ini复制代码File file = new File("D:\\java\\测试文件夹");

ini复制代码FileAlterationObserver fileObserver = new FileAlterationObserver(file);

arduino复制代码fileObserver.addListener(new FileListenUtil());

ini复制代码FileAlterationMonitor fileMonitor = new FileAlterationMonitor(TimeUnit.SECONDS.toMillis(5), fileObserver);

ini复制代码fileMonitor.start();

bash复制代码yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum update
yum repolist

bash复制代码yum -y install easy-rsa

bash复制代码mkdir -p /opt/easy-rsa
cp -a /usr/share/easy-rsa/3.0.8/* /opt/easy-rsa/
cp -a /usr/share/doc/easy-rsa-3.0.8/vars.example /opt/easy-rsa/vars

bash复制代码set_var EASYRSA_DN      "cn_only"
set_var EASYRSA_REQ_COUNTRY     "CN"
set_var EASYRSA_REQ_PROVINCE    "Shanghai"
set_var EASYRSA_REQ_CITY        "Shanghai"
set_var EASYRSA_REQ_ORG         "lucifer"
set_var EASYRSA_REQ_EMAIL       "pc1107750981@163.com"
set_var EASYRSA_NS_SUPPORT      "yes"

bash复制代码[root@openvpn easy-rsa]# cd /opt/easy-rsa/
[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa init-pki

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars

init-pki complete; you may now create a CA or requests.
Your newly created PKI dir is: /opt/easy-rsa/pki

bash复制代码[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa build-ca

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars
Using SSL: openssl OpenSSL 1.0.2k-fips  26 Jan 2017

Enter New CA Key Passphrase: 
Re-Enter New CA Key Passphrase: 
Generating RSA private key, 2048 bit long modulus
.....+++
..........................................+++
e is 65537 (0x10001)
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Common Name (eg: your user, host, or server name) [Easy-RSA CA]:

CA creation complete and you may now import and sign cert requests.
Your new CA certificate file for publishing is at:
/opt/easy-rsa/pki/ca.crt

bash复制代码[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa gen-req server nopass

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars
Using SSL: openssl OpenSSL 1.0.2k-fips  26 Jan 2017
Generating a 2048 bit RSA private key
...........................+++
........................................................................+++
writing new private key to '/opt/easy-rsa/pki/easy-rsa-1326.TIfM4D/tmp.rxSnIM'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Common Name (eg: your user, host, or server name) [server]:

Keypair and certificate request completed. Your files are:
req: /opt/easy-rsa/pki/reqs/server.req
key: /opt/easy-rsa/pki/private/server.key

bash复制代码[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa sign server server

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars
Using SSL: openssl OpenSSL 1.0.2k-fips  26 Jan 2017


You are about to sign the following certificate.
Please check over the details shown below for accuracy. Note that this request
has not been cryptographically verified. Please be sure it came from a trusted
source or that you have verified the request checksum with the sender.

Request subject, to be signed as a server certificate for 825 days:

subject=
    commonName                = server


Type the word 'yes' to continue, or any other input to abort.
  Confirm request details: yes
Using configuration from /opt/easy-rsa/pki/easy-rsa-1397.ds5qpo/tmp.lX0IFN
Enter pass phrase for /opt/easy-rsa/pki/private/ca.key:
Check that the request matches the signature
Signature ok
The Subject's Distinguished Name is as follows
commonName            :ASN.1 12:'server'
Certificate is to be certified until Jun  3 14:02:46 2023 GMT (825 days)

Write out database with 1 new entries
Data Base Updated

Certificate created at: /opt/easy-rsa/pki/issued/server.crt

bash复制代码/opt/easy-rsa/easyrsa gen-dh

bash复制代码[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa gen-req client nopass

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars
Using SSL: openssl OpenSSL 1.0.2k-fips  26 Jan 2017
Generating a 2048 bit RSA private key
..................................................................+++
...................................................................................................................+++
writing new private key to '/opt/easy-rsa/pki/easy-rsa-1761.HYs4Xv/tmp.z02JuI'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Common Name (eg: your user, host, or server name) [client]:

Keypair and certificate request completed. Your files are:
req: /opt/easy-rsa/pki/reqs/client.req
key: /opt/easy-rsa/pki/private/client.key

bash复制代码[root@openvpn easy-rsa]# /opt/easy-rsa/easyrsa sign client client

Note: using Easy-RSA configuration from: /opt/easy-rsa/vars
Using SSL: openssl OpenSSL 1.0.2k-fips  26 Jan 2017


You are about to sign the following certificate.
Please check over the details shown below for accuracy. Note that this request
has not been cryptographically verified. Please be sure it came from a trusted
source or that you have verified the request checksum with the sender.

Request subject, to be signed as a client certificate for 825 days:

subject=
    commonName                = client


Type the word 'yes' to continue, or any other input to abort.
  Confirm request details: yes
Using configuration from /opt/easy-rsa/pki/easy-rsa-1828.VwQHeF/tmp.eYqBSS
Enter pass phrase for /opt/easy-rsa/pki/private/ca.key:
Check that the request matches the signature
Signature ok
The Subject's Distinguished Name is as follows
commonName            :ASN.1 12:'client'
Certificate is to be certified until Jun  3 14:09:37 2023 GMT (825 days)

Write out database with 1 new entries
Data Base Updated

Certificate created at: /opt/easy-rsa/pki/issued/client.crt

bash复制代码yum -y install openvpn

bash复制代码port 1194 #端口
proto udp #协议
dev tun #采用路由隧道模式tun
ca ca.crt #ca证书文件位置
cert server.crt #服务端公钥名称
key server.key #服务端私钥名称
dh dh.pem #交换证书
server 10.8.0.0 255.255.255.0 #给客户端分配地址池，注意：不能和VPN服务器内网网段有相同
push "route 192.168.31.1 255.255.255.0" #允许客户端访问内网192.168.31.1网段
ifconfig-pool-persist ipp.txt #地址池记录文件位置
keepalive 10 120 #存活时间，10秒ping一次,120 如未收到响应则视为断线
max-clients 100 #最多允许100个客户端连接
status openvpn-status.log #日志记录位置
verb 3 #openvpn版本
client-to-client #客户端与客户端之间支持通信
log /var/log/openvpn.log #openvpn日志记录位置
persist-key #通过keepalive检测超时后，重新启动VPN，不重新读取keys，保留第一次使用的keys。
persist-tun #检测超时后，重新启动VPN，一直保持tun是linkup的。否则网络会先linkdown然后再linkup
duplicate-cn

bash复制代码cp -a /opt/easy-rsa/pki/ca.crt /etc/openvpn/
cp -a /opt/easy-rsa/pki/issued/server.crt /etc/openvpn/
cp -a /opt/easy-rsa/pki/private/server.key /etc/openvpn/
cp -a /opt/easy-rsa/pki/dh.pem /etc/openvpn/

bash复制代码systemctl -f enable openvpn@server.service
systemctl start openvpn@server.service

bash复制代码/opt/easy-rsa/pki/ca.crt 
/opt/easy-rsa/pki/issued/client.crt
/opt/easy-rsa/pki/private/client.key

bash复制代码client #指定当前VPN是客户端
dev tun #使用tun隧道传输协议
proto udp #使用udp协议传输数据
remote 192.168.31.168 1194 #openvpn服务器IP地址端口号
resolv-retry infinite #断线自动重新连接，在网络不稳定的情况下非常有用
nobind #不绑定本地特定的端口号
ca ca.crt #指定CA证书的文件路径
cert client.crt #指定当前客户端的证书文件路径
key client.key #指定当前客户端的私钥文件路径
verb 3 #指定日志文件的记录详细级别，可选0-9，等级越高日志内容越详细
persist-key #通过keepalive检测超时后，重新启动VPN，不重新读取keys，保留第一次使用的keys
persist-tun #检测超时后，重新启动VPN，一直保持tun是linkup的。否则网络会先linkdown然后再linkup

java复制代码MeterRegistry registry = new SimpleMeterRegistry(); 
Counter counter = registry.counter("counter");
counter.increment();

java复制代码CompositeMeterRegistry composite = new CompositeMeterRegistry();

Counter compositeCounter = composite.counter("counter");
compositeCounter.increment(); // <- 实际上这一步操作是无效的,但是不会报错

SimpleMeterRegistry simple = new SimpleMeterRegistry();
composite.add(simple);  // <- 向CompositeMeterRegistry实例中添加SimpleMeterRegistry实例

compositeCounter.increment();  // <-计数成功

java复制代码Metrics.addRegistry(new SimpleMeterRegistry());
Counter counter = Metrics.counter("counter", "tag-1", "tag-2");
counter.increment();

java复制代码MeterRegistry registry = ...
registry.timer("http.server.requests");

java复制代码MeterRegistry registry = ...
registry.counter("database.calls", "db", "users")
registry.counter("http.requests", "uri", "/api/users")

java复制代码MeterRegistry registry = ...
registry.counter("calls",
    "class", "database",
    "db", "users");

registry.counter("calls",
    "class", "http",
    "uri", "/api/users");

java复制代码MeterRegistry registry = ...
registry.counter("calls",
    "class", "database",
    "db", "users");

registry.counter("calls",
    "class", "http",
    "uri", "/api/users");
 

MeterRegistry registry = ...
registry.config().commonTags("stack", "prod", "region", "us-east-1");
// 和上面的意义是一样的
registry.config().commonTags(Arrays.asList(Tag.of("stack", "prod"), Tag.of("region", "us-east-1")));

java复制代码public interface Tag extends Comparable<Tag> {
    String getKey();

    String getValue();

    static Tag of(String key, String value) {
        return new ImmutableTag(key, value);
    }

    default int compareTo(Tag o) {
        return this.getKey().compareTo(o.getKey());
    }
}

java复制代码MeterRegistry registry = ...
registry.config()
    .meterFilter(MeterFilter.ignoreTags("http"))
    .meterFilter(MeterFilter.denyNameStartsWith("jvm"));

java复制代码MeterRegistry meterRegistry = new SimpleMeterRegistry();
Counter counter = meterRegistry.counter("http.request", "createOrder", "/order/create");
counter.increment();
System.out.println(counter.measure()); // [Measurement{statistic='COUNT', value=1.0}]

java复制代码//实体
@Data
public class Order {

	private String orderId;
	private Integer amount;
	private String channel;
	private LocalDateTime createTime;
}


public class CounterMain {

	private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd");

	static {
            Metrics.addRegistry(new SimpleMeterRegistry());
        }

        public static void main(String[] args) throws Exception {
            Order order1 = new Order();
            order1.setOrderId("ORDER_ID_1");
            order1.setAmount(100);
            order1.setChannel("CHANNEL_A");
            order1.setCreateTime(LocalDateTime.now());
            createOrder(order1);
            Order order2 = new Order();
            order2.setOrderId("ORDER_ID_2");
            order2.setAmount(200);
            order2.setChannel("CHANNEL_B");
            order2.setCreateTime(LocalDateTime.now());
            createOrder(order2);
            Search.in(Metrics.globalRegistry).meters().forEach(each -> {
                StringBuilder builder = new StringBuilder();
                builder.append("name:")
                        .append(each.getId().getName())
                        .append(",tags:")
                        .append(each.getId().getTags())
                        .append(",type:").append(each.getId().getType())
                        .append(",value:").append(each.measure());
                System.out.println(builder.toString());
            });
	}

	private static void createOrder(Order order) {
		//忽略订单入库等操作
		Metrics.counter("order.create",
				"channel", order.getChannel(),
				"createTime", FORMATTER.format(order.getCreateTime())).increment();
	}
}

java复制代码name:order.create,tags:[tag(channel=CHANNEL_A), tag(createTime=2018-11-10)],type:COUNTER,value:[Measurement{statistic='COUNT', value=1.0}]
name:order.create,tags:[tag(channel=CHANNEL_B), tag(createTime=2018-11-10)],type:COUNTER,value:[Measurement{statistic='COUNT', value=1.0}]

java复制代码public class CounterBuilderMain {

        public static void main(String[] args) throws Exception{
            Counter counter = Counter.builder("name")  //名称
                    .baseUnit("unit") //基础单位
                    .description("desc") //描述
                    .tag("tagKey", "tagValue")  //标签
                    .register(new SimpleMeterRegistry());//绑定的MeterRegistry
            counter.increment();
        }
}

java复制代码public class FunctionCounterMain {

        public static void main(String[] args) throws Exception {
            MeterRegistry registry = new SimpleMeterRegistry();
            AtomicInteger n = new AtomicInteger(0);
            //这里ToDoubleFunction匿名实现其实可以使用Lambda表达式简化为AtomicInteger::get
            FunctionCounter.builder("functionCounter", n, new ToDoubleFunction<AtomicInteger>() {
                @Override
                public double applyAsDouble(AtomicInteger value) {
                    return value.get();
                }
            }).baseUnit("function")
                    .description("functionCounter")
                    .tag("createOrder", "CHANNEL-A")
                    .register(registry);
            //下面模拟三次计数		
            n.incrementAndGet();
            n.incrementAndGet();
            n.incrementAndGet();
        }
}

java复制代码public interface Timer extends Meter {
    ...
    void record(long var1, TimeUnit var3);

    default void record(Duration duration) {
        this.record(duration.toNanos(), TimeUnit.NANOSECONDS);
    }

    <T> T record(Supplier<T> var1);

    <T> T recordCallable(Callable<T> var1) throws Exception;

    void record(Runnable var1);

    default Runnable wrap(Runnable f) {
        return () -> {
            this.record(f);
        };
    }

    default <T> Callable<T> wrap(Callable<T> f) {
        return () -> {
            return this.recordCallable(f);
        };
    }

    long count();

    double totalTime(TimeUnit var1);

    default double mean(TimeUnit unit) {
        return this.count() == 0L ? 0.0D : this.totalTime(unit) / (double)this.count();
    }

    double max(TimeUnit var1);
	...
}

java复制代码Timer timer = ...
timer.record(() -> dontCareAboutReturnValue());
timer.recordCallable(() -> returnValue());

Runnable r = timer.wrap(() -> dontCareAboutReturnValue());
Callable c = timer.wrap(() -> returnValue());

java复制代码public class TimerMain {

        private static final Random R = new Random();

        static {
            Metrics.addRegistry(new SimpleMeterRegistry());
        }

        public static void main(String[] args) throws Exception {
            Order order1 = new Order();
            order1.setOrderId("ORDER_ID_1");
            order1.setAmount(100);
            order1.setChannel("CHANNEL_A");
            order1.setCreateTime(LocalDateTime.now());
            Timer timer = Metrics.timer("timer", "createOrder", "cost");
            timer.record(() -> createOrder(order1));
        }

        private static void createOrder(Order order) {
            try {
                TimeUnit.SECONDS.sleep(R.nextInt(5)); //模拟方法耗时
            } catch (InterruptedException e) {
                //no-op
            }
        }
}

java复制代码MeterRegistry registry = ...
Timer timer = Timer
    .builder("my.timer")
    .description("a description of what this timer does") // 可选
    .tags("region", "test") // 可选
    .register(registry);

java复制代码Timer.Sample sample = Timer.start(registry);

// 这里做业务逻辑
Response response = ...

sample.stop(registry.timer("my.timer", "response", response.status()));

java复制代码public interface FunctionTimer extends Meter {
    static <T> Builder<T> builder(String name, T obj, ToLongFunction<T> countFunction,
                                  ToDoubleFunction<T> totalTimeFunction,
                                  TimeUnit totalTimeFunctionUnit) {
        return new Builder<>(name, obj, countFunction, totalTimeFunction, totalTimeFunctionUnit);
    }
	...
}

java复制代码IMap<?, ?> cache = ...; // 假设使用了Hazelcast缓存
registry.more().timer("cache.gets.latency", Tags.of("name", cache.getName()), cache,
    c -> c.getLocalMapStats().getGetOperationCount(),  //实际上就是cache的一个方法，记录缓存生命周期初始化的增量(个数)
    c -> c.getLocalMapStats().getTotalGetLatency(),  // Get操作的延迟时间总量，可以理解为耗时
    TimeUnit.NANOSECONDS
);

java复制代码public class FunctionTimerMain {

        public static void main(String[] args) throws Exception {
            //这个是为了满足参数,暂时不需要理会
            Object holder = new Object();
            AtomicLong totalTimeNanos = new AtomicLong(0);
            AtomicLong totalCount = new AtomicLong(0);
            FunctionTimer.builder("functionTimer", holder, p -> totalCount.get(), 
                    p -> totalTimeNanos.get(), TimeUnit.NANOSECONDS)
                    .register(new SimpleMeterRegistry());
            totalTimeNanos.addAndGet(10000000);
            totalCount.incrementAndGet();
        }
}

java复制代码@Timed(value = "aws.scrape", longTask = true)
@Scheduled(fixedDelay = 360000)
void scrapeResources() {
    //这里做相对耗时的业务逻辑
}

java复制代码public class LongTaskTimerMain {

        public static void main(String[] args) throws Exception{
            MeterRegistry meterRegistry = new SimpleMeterRegistry();
            LongTaskTimer longTaskTimer = meterRegistry.more().longTaskTimer("longTaskTimer");
            longTaskTimer.record(() -> {

                //这里编写Task的逻辑
            });
            //或者这样
            Metrics.more().longTaskTimer("longTaskTimer").record(()-> {
                //这里编写Task的逻辑
            });
        }
}

java复制代码List<String> list = registry.gauge("listGauge", Collections.emptyList(), new ArrayList<>(), List::size); 
List<String> list2 = registry.gaugeCollectionSize("listSize2", Tags.empty(), new ArrayList<>()); 
Map<String, Integer> map = registry.gaugeMapSize("mapGauge", Tags.empty(), new HashMap<>());

java复制代码AtomicInteger n = registry.gauge("numberGauge", new AtomicInteger(0));
n.set(1);
n.set(2);

java复制代码//一般我们不需要操作Gauge实例
Gauge gauge = Gauge
    .builder("gauge", myObj, myObj::gaugeValue)
    .description("a description of what this gauge does") // 可选
    .tags("region", "test") // 可选
    .register(registry);

java复制代码public class GaugeMain {

	private static final MeterRegistry MR = new SimpleMeterRegistry();
	private static final BlockingQueue<Message> QUEUE = new ArrayBlockingQueue<>(500);
	private static BlockingQueue<Message> REAL_QUEUE;

        static {
            REAL_QUEUE = MR.gauge("messageGauge", QUEUE, Collection::size);
        }

        public static void main(String[] args) throws Exception {
            consume();
            Message message = new Message();
            message.setUserId(1L);
            message.setContent("content");
            REAL_QUEUE.put(message);
        }

        private static void consume() throws Exception {
            new Thread(() -> {
                while (true) {
                    try {
                        Message message = REAL_QUEUE.take();
                        //handle message
                        System.out.println(message);
                    } catch (InterruptedException e) {
                        //no-op
                    }
                }
            }).start();
        }
}

java复制代码public class TimeGaugeMain {

        private static final SimpleMeterRegistry R = new SimpleMeterRegistry();

        public static void main(String[] args) throws Exception{
            AtomicInteger count = new AtomicInteger();
            TimeGauge.Builder<AtomicInteger> timeGauge = TimeGauge.builder("timeGauge", count,
                    TimeUnit.SECONDS, AtomicInteger::get);
            timeGauge.register(R);
            count.addAndGet(10086);
            print();
            count.set(1);
            print();
        }

        private static void print()throws Exception{
            Search.in(R).meters().forEach(each -> {
                StringBuilder builder = new StringBuilder();
                builder.append("name:")
                        .append(each.getId().getName())
                        .append(",tags:")
                        .append(each.getId().getTags())
                        .append(",type:").append(each.getId().getType())
                        .append(",value:").append(each.measure());
                System.out.println(builder.toString());
            });
        }
    }

//输出
name:timeGauge,tags:[],type:GAUGE,value:[Measurement{statistic='VALUE', value=10086.0}]
name:timeGauge,tags:[],type:GAUGE,value:[Measurement{statistic='VALUE', value=1.0}]

java复制代码DistributionSummary summary = registry.summary("response.size");

java复制代码DistributionSummary summary = DistributionSummary
    .builder("response.size")
    .description("a description of what this summary does") // 可选
    .baseUnit("bytes") // 可选
    .tags("region", "test") // 可选
    .scale(100) // 可选
    .register(registry);

java复制代码public class DistributionSummaryMain {
	
        private static final DistributionSummary DS  = DistributionSummary.builder("cacheHitPercent")
                .register(new SimpleMeterRegistry());

        private static final LoadingCache<String, String> CACHE = CacheBuilder.newBuilder()
                .maximumSize(1000)
                .recordStats()
                .expireAfterWrite(60, TimeUnit.SECONDS)
                .build(new CacheLoader<String, String>() {
                    @Override
                    public String load(String s) throws Exception {
                        return selectFromDatabase();
                    }
                });

        public static void main(String[] args) throws Exception{
            String key = "doge";
            String value = CACHE.get(key);
            record();
        }

        private static void record()throws Exception{
            CacheStats stats = CACHE.stats();
            BigDecimal hitCount = new BigDecimal(stats.hitCount());
            BigDecimal requestCount = new BigDecimal(stats.requestCount());
            DS.record(hitCount.divide(requestCount,2,BigDecimal.ROUND_HALF_DOWN).doubleValue());
        }
}

xml复制代码<dependencyManagement>
      <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-dependencies</artifactId>
              <version>2.1.0.RELEASE</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
      </dependencies>
  </dependencyManagement>
  <dependencies>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-actuator</artifactId>
      </dependency>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-aop</artifactId>
      </dependency>
      <dependency>
          <groupId>org.projectlombok</groupId>
          <artifactId>lombok</artifactId>
          <version>1.16.22</version>
      </dependency>
<dependency>
          <groupId>io.micrometer</groupId>
          <artifactId>micrometer-registry-prometheus</artifactId>
          <version>1.1.0</version>
      </dependency>
  </dependencies>

java复制代码//实体
@Data
public class Message {

        private String orderId;
        private Long userId;
        private String content;
    }

    @Data
    public class Order {

        private String orderId;
        private Long userId;
        private Integer amount;
        private LocalDateTime createTime;
    }

    //控制器和服务类
    @RestController
    public class OrderController {

        @Autowired
        private OrderService orderService;

        @PostMapping(value = "/order")
        public ResponseEntity<Boolean> createOrder(@RequestBody Order order){
            return ResponseEntity.ok(orderService.createOrder(order));
        }
    }

    @Slf4j
    @Service
    public class OrderService {

        private static final Random R = new Random();

        @Autowired
        private MessageService messageService;

        public Boolean createOrder(Order order) {
            //模拟下单
            try {
                int ms = R.nextInt(50) + 50;
                TimeUnit.MILLISECONDS.sleep(ms);
                log.info("保存订单模拟耗时{}毫秒...", ms);
            } catch (Exception e) {
                //no-op
            }
            //记录下单总数
            Metrics.counter("order.count", "order.channel", order.getChannel()).increment();
            //发送消息
            Message message = new Message();
            message.setContent("模拟短信...");
            message.setOrderId(order.getOrderId());
            message.setUserId(order.getUserId());
            messageService.sendMessage(message);
            return true;
        }
    }

    @Slf4j
    @Service
    public class MessageService implements InitializingBean {

        private static final BlockingQueue<Message> QUEUE = new ArrayBlockingQueue<>(500);
        private static BlockingQueue<Message> REAL_QUEUE;
        private static final Executor EXECUTOR = Executors.newSingleThreadExecutor();
        private static final Random R = new Random();

        static {
            REAL_QUEUE = Metrics.gauge("message.gauge", Tags.of("message.gauge", "message.queue.size"), QUEUE, Collection::size);
        }

        public void sendMessage(Message message) {
            try {
                REAL_QUEUE.put(message);
            } catch (InterruptedException e) {
                //no-op
            }
        }

        @Override
        public void afterPropertiesSet() throws Exception {
            EXECUTOR.execute(() -> {
                while (true) {
                    try {
                        Message message = REAL_QUEUE.take();
                        log.info("模拟发送短信,orderId:{},userId:{},内容:{},耗时:{}毫秒", message.getOrderId(), message.getUserId(),
                                message.getContent(), R.nextInt(50));
                    } catch (Exception e) {
                        throw new IllegalStateException(e);
                    }
                }
            });
        }
    }

    //切面类
    @Component
    @Aspect
    public class TimerAspect {

        @Around(value = "execution(* club.throwable.smp.service.*Service.*(..))")
        public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
            Signature signature = joinPoint.getSignature();
            MethodSignature methodSignature = (MethodSignature) signature;
            Method method = methodSignature.getMethod();
            Timer timer = Metrics.timer("method.cost.time", "method.name", method.getName());
            ThrowableHolder holder = new ThrowableHolder();
            Object result = timer.recordCallable(() -> {
                try {
                    return joinPoint.proceed();
                } catch (Throwable e) {
                    holder.throwable = e;
                }
                return null;
            });
            if (null != holder.throwable) {
                throw holder.throwable;
            }
            return result;
        }

        private class ThrowableHolder {

            Throwable throwable;
        }
}

yaml复制代码server:
  port: 9091
management:
  server:
    port: 10091
  endpoints:
    web:
      exposure:
		include: '*'
	  base-path: /management

xml复制代码management.endpoint.${端点ID}.enabled=true/false可以查

xml复制代码management.endpoints.web.exposure.include=info,health
management.endpoints.web.exposure.exclude=prometheus

shell复制代码wget https://github.com/prometheus/prometheus/releases/download/v2.5.0/prometheus-2.5.0.linux-amd64.tar.gz
tar xvfz prometheus-*.tar.gz
cd prometheus-*

yml复制代码scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.
    # 这里配置需要拉取度量信息的URL路径，这里选择应用程序的prometheus端点
	metrics_path: /management/prometheus
	static_configs:
	# 这里配置host和port
    - targets: ['localhost:10091']

shell复制代码# 参数 --storage.tsdb.path=存储数据的路径，默认路径为./data
./prometheus --config.file=prometheus.yml  --log.level=debug

bash复制代码wget https://s3-us-west-2.amazonaws.com/grafana-releases/release/grafana-5.3.4-1.x86_64.rpm 
sudo yum localinstall grafana-5.3.4-1.x86_64.rpm

html复制代码app_register 0.0
app_login 0.0

java复制代码    @RequestMapping(value = "/meter", method = RequestMethod.GET)
    @ResponseBody
    public void getMeg(HttpServletResponse response) throws IOException {
        
        Map map = Metrics.globalRegistry.getMeters().stream().collect(
                Collectors.toMap(meter -> meter.getId().getName(),
                        meter -> Metrics.counter(meter.getId().getName()).count()));

        StringBuffer html = new StringBuffer();
        map.forEach((key,value) ->{
            html.append(key).append(" ").append(value).append("\n");
        });
        response.setContentType("text/plain; version=0.0.4;charset=utf-8");
        response.setContentLength(html.toString().length());
        ServletOutputStream out = response.getOutputStream();
        out.write(html.toString().getBytes());
        out.flush();
    }

java复制代码public interface Servlet {
    //初始化
    public void init(ServletConfig config) throws ServletException;

    //响应请求
    public void service(ServletRequest req, ServletResponse res)
            throws ServletException, IOException;

    //获取servlet信息
    public String getServletInfo();
        
    //服务停止时回调
    public void destroy();
}

java复制代码@Override
public final void init() throws ServletException {

   // 设置servlet的属性
   PropertyValues pvs = new ServletConfigPropertyValues(getServletConfig(), this.requiredProperties);
   if (!pvs.isEmpty()) {
      try {
         BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(this);
         ResourceLoader resourceLoader = new ServletContextResourceLoader(getServletContext());
         bw.registerCustomEditor(Resource.class, new ResourceEditor(resourceLoader, getEnvironment()));
         initBeanWrapper(bw);
         bw.setPropertyValues(pvs, true);
      }
      catch (BeansException ex) {
         if (logger.isErrorEnabled()) {
            logger.error("Failed to set bean properties on servlet '" + getServletName() + "'", ex);
         }
         throw ex;
      }
   }

   // 具体的初始化方法交给子类实现
   initServletBean();
}
//空实现，具体的由子类实现
protected void initServletBean() throws ServletException {
}

java复制代码@Override
protected final void initServletBean() throws ServletException {
   getServletContext().log("Initializing Spring " + getClass().getSimpleName() + " '" + getServletName() + "'");
   if (logger.isInfoEnabled()) {
      logger.info("Initializing Servlet '" + getServletName() + "'");
   }
   long startTime = System.currentTimeMillis();

   try {
      //这里初始化了web的上下文，这里会初始化Servlet的九大策略
      this.webApplicationContext = initWebApplicationContext();
      //这个方法也是空实现
      initFrameworkServlet();
   }
   catch (ServletException | RuntimeException ex) {
      logger.error("Context initialization failed", ex);
      throw ex;
   }

   if (logger.isDebugEnabled()) {
      String value = this.enableLoggingRequestDetails ?
            "shown which may lead to unsafe logging of potentially sensitive data" :
            "masked to prevent unsafe logging of potentially sensitive data";
      logger.debug("enableLoggingRequestDetails='" + this.enableLoggingRequestDetails +
            "': request parameters and headers will be " + value);
   }

   if (logger.isInfoEnabled()) {
      logger.info("Completed initialization in " + (System.currentTimeMillis() - startTime) + " ms");
   }
}

//初始化上下文
protected WebApplicationContext initWebApplicationContext() {
   WebApplicationContext rootContext =
         WebApplicationContextUtils.getWebApplicationContext(getServletContext());
   WebApplicationContext wac = null;

   if (this.webApplicationContext != null) {
      wac = this.webApplicationContext;
      if (wac instanceof ConfigurableWebApplicationContext) {
         ConfigurableWebApplicationContext cwac = (ConfigurableWebApplicationContext) wac;
         if (!cwac.isActive()) {
            if (cwac.getParent() == null) {
               cwac.setParent(rootContext);
            }
            configureAndRefreshWebApplicationContext(cwac);
         }
      }
   }
   if (wac == null) {
      wac = findWebApplicationContext();
   }
   if (wac == null) {
      wac = createWebApplicationContext(rootContext);
   }

   if (!this.refreshEventReceived) {
      synchronized (this.onRefreshMonitor) {
          //springboot只会进入这个方法，这个方法是空实现，具体实现在子类DispatchServlet
         onRefresh(wac);
      }
   }

   if (this.publishContext) {
      String attrName = getServletContextAttributeName();
      getServletContext().setAttribute(attrName, wac);
   }

   return wac;
}

java复制代码@Override
protected void onRefresh(ApplicationContext context) {
   initStrategies(context);
}

//初始化策略
protected void initStrategies(ApplicationContext context) {
   initMultipartResolver(context);
   initLocaleResolver(context);
   initThemeResolver(context);
   //这个是我们关注的核心，Controller注册就在这里实现
   initHandlerMappings(context);
   //这个是处理Controller方法调用的，逻辑跟上面的initHandlerMappings差不多
   initHandlerAdapters(context);
   initHandlerExceptionResolvers(context);
   initRequestToViewNameTranslator(context);
   initViewResolvers(context);
   initFlashMapManager(context);
}

java复制代码private void initHandlerMappings(ApplicationContext context) {
   this.handlerMappings = null;
    //默认为true
   if (this.detectAllHandlerMappings) {
      //默认的HandlerMapping有8个，这里我们只关心RequestMappingHandlerMapping这个类
      Map<String, HandlerMapping> matchingBeans =
            BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerMapping.class, true, false);
      if (!matchingBeans.isEmpty()) {
         this.handlerMappings = new ArrayList<>(matchingBeans.values());
         //排序
         AnnotationAwareOrderComparator.sort(this.handlerMappings);
      }
   }
   else {
      try {
         HandlerMapping hm = context.getBean(HANDLER_MAPPING_BEAN_NAME, HandlerMapping.class);
         //这里就让Serlvet和Controller建立起了间接关系了，这个方法主要是为了给handlerMappings属性赋值
         this.handlerMappings = Collections.singletonList(hm);
      }
      catch (NoSuchBeanDefinitionException ex) {
      }
   }

   //这里如果没有HanlderMapping的话，会给一个默认的处理
   if (this.handlerMappings == null) {
      this.handlerMappings = getDefaultStrategies(context, HandlerMapping.class);
      if (logger.isTraceEnabled()) {
         logger.trace("No HandlerMappings declared for servlet '" + getServletName() +
               "': using default strategies from DispatcherServlet.properties");
      }
   }
}

java复制代码/**
* 这个方法只是将ServletRequest强转为HttpServletRequest
* ServletResponse强转为HttpServletResponse
*/
@Override
public void service(ServletRequest req, ServletResponse res)
    throws ServletException, IOException {

    HttpServletRequest  request;
    HttpServletResponse response;

    try {
        request = (HttpServletRequest) req;
        response = (HttpServletResponse) res;
    } catch (ClassCastException e) {
        throw new ServletException(lStrings.getString("http.non_http"));
    }
    //接着看这个
    service(request, response);
}

protected void service(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException {
    //获取方法类型
    String method = req.getMethod();
    //根据不同的方法类型调用不同的方法，从doGet进去，看子类FrameworkServlet的doGet方法
    if (method.equals(METHOD_GET)) {
        long lastModified = getLastModified(req);
        if (lastModified == -1) {
            doGet(req, resp);
        } else {
            long ifModifiedSince;
            try {
                ifModifiedSince = req.getDateHeader(HEADER_IFMODSINCE);
            } catch (IllegalArgumentException iae) {
                ifModifiedSince = -1;
            }
            if (ifModifiedSince < (lastModified / 1000 * 1000)) {
                maybeSetLastModified(resp, lastModified);
                doGet(req, resp);
            } else {
                resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
            }
        }

    } else if (method.equals(METHOD_HEAD)) {
        long lastModified = getLastModified(req);
        maybeSetLastModified(resp, lastModified);
        doHead(req, resp);

    } else if (method.equals(METHOD_POST)) {
        doPost(req, resp);

    } else if (method.equals(METHOD_PUT)) {
        doPut(req, resp);

    } else if (method.equals(METHOD_DELETE)) {
        doDelete(req, resp);

    } else if (method.equals(METHOD_OPTIONS)) {
        doOptions(req,resp);

    } else if (method.equals(METHOD_TRACE)) {
        doTrace(req,resp);

    } else {
        String errMsg = lStrings.getString("http.method_not_implemented");
        Object[] errArgs = new Object[1];
        errArgs[0] = method;
        errMsg = MessageFormat.format(errMsg, errArgs);

        resp.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED, errMsg);
    }
}

//FrameworkServlet的doGet方法
@Override
protected final void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    //继续跟
   processRequest(request, response);
}

rotected final void processRequest(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

   long startTime = System.currentTimeMillis();
   Throwable failureCause = null;

   LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();
   LocaleContext localeContext = buildLocaleContext(request);

   RequestAttributes previousAttributes = RequestContextHolder.getRequestAttributes();
   ServletRequestAttributes requestAttributes = buildRequestAttributes(request, response, previousAttributes);

   WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
   asyncManager.registerCallableInterceptor(FrameworkServlet.class.getName(), new RequestBindingInterceptor());

   initContextHolders(request, localeContext, requestAttributes);

   try {
       //这里处理请求，继续跟，看子类DispatchServlet的doService方法
      doService(request, response);
   }
   catch (ServletException | IOException ex) {
      failureCause = ex;
      throw ex;
   }
   catch (Throwable ex) {
      failureCause = ex;
      throw new NestedServletException("Request processing failed", ex);
   }

   finally {
      resetContextHolders(request, previousLocaleContext, previousAttributes);
      if (requestAttributes != null) {
         requestAttributes.requestCompleted();
      }
      logResult(request, response, failureCause, asyncManager);
      publishRequestHandledEvent(request, response, startTime, failureCause);
   }
}

java复制代码@Override
protected void doService(HttpServletRequest request, HttpServletResponse response) throws Exception {
    // 打印日志
   logRequest(request);
   //保存快照
   Map<String, Object> attributesSnapshot = null;
   if (WebUtils.isIncludeRequest(request)) {
      attributesSnapshot = new HashMap<>();
      Enumeration<?> attrNames = request.getAttributeNames();
      while (attrNames.hasMoreElements()) {
         String attrName = (String) attrNames.nextElement();
         if (this.cleanupAfterInclude || attrName.startsWith(DEFAULT_STRATEGIES_PREFIX)) {
            attributesSnapshot.put(attrName, request.getAttribute(attrName));
         }
      }
   }
    //设置属性
   request.setAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE, getWebApplicationContext());
   request.setAttribute(LOCALE_RESOLVER_ATTRIBUTE, this.localeResolver);
   request.setAttribute(THEME_RESOLVER_ATTRIBUTE, this.themeResolver);
   request.setAttribute(THEME_SOURCE_ATTRIBUTE, getThemeSource());

   if (this.flashMapManager != null) {
      FlashMap inputFlashMap = this.flashMapManager.retrieveAndUpdate(request, response);
      if (inputFlashMap != null) {
         request.setAttribute(INPUT_FLASH_MAP_ATTRIBUTE, Collections.unmodifiableMap(inputFlashMap));
      }
      request.setAttribute(OUTPUT_FLASH_MAP_ATTRIBUTE, new FlashMap());
      request.setAttribute(FLASH_MAP_MANAGER_ATTRIBUTE, this.flashMapManager);
   }

   try {
       //处理请求核心方法
      doDispatch(request, response);
   }
   finally {
      if (!WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {
         if (attributesSnapshot != null) {
            restoreAttributesAfterInclude(request, attributesSnapshot);
         }
      }
   }
}

java复制代码protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
   HttpServletRequest processedRequest = request;
   HandlerExecutionChain mappedHandler = null;
   boolean multipartRequestParsed = false;

   WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);

   try {
      ModelAndView mv = null;
      Exception dispatchException = null;

      try {
         processedRequest = checkMultipart(request);
         multipartRequestParsed = (processedRequest != request);

         // 获取当前请求的handler
         mappedHandler = getHandler(processedRequest);
         if (mappedHandler == null) {
             //404
            noHandlerFound(processedRequest, response);
            return;
         }

         // 获取处理当前请求的handlerAdapter
         HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
         
         String method = request.getMethod();
         boolean isGet = "GET".equals(method);
         if (isGet || "HEAD".equals(method)) {
            long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
            if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {
               return;
            }
         }
          //调用前置拦截器
         if (!mappedHandler.applyPreHandle(processedRequest, response)) {
            return;
         }

         // 请求对应的方法在这里被执行
         mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

         if (asyncManager.isConcurrentHandlingStarted()) {
            return;
         }

         applyDefaultViewName(processedRequest, mv);
         //调用后置拦截器
         mappedHandler.applyPostHandle(processedRequest, response, mv);
      }
      catch (Exception ex) {
         dispatchException = ex;
      }
      catch (Throwable err) {
         // As of 4.3, we're processing Errors thrown from handler methods as well,
         // making them available for @ExceptionHandler methods and other scenarios.
         dispatchException = new NestedServletException("Handler dispatch failed", err);
      }
      processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
   }
   catch (Exception ex) {
      triggerAfterCompletion(processedRequest, response, mappedHandler, ex);
   }
   catch (Throwable err) {
      triggerAfterCompletion(processedRequest, response, mappedHandler,
            new NestedServletException("Handler processing failed", err));
   }
   finally {
      if (asyncManager.isConcurrentHandlingStarted()) {
         // Instead of postHandle and afterCompletion
         if (mappedHandler != null) {
            mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);
         }
      }
      else {
         // Clean up any resources used by a multipart request.
         if (multipartRequestParsed) {
            cleanupMultipart(processedRequest);
         }
      }
   }
}

@Nullable
protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
   if (this.handlerMappings != null) {
      for (HandlerMapping mapping : this.handlerMappings) {
      //这里的mapping就是接下来要讲到的RequestMappingHandlerMapping
         HandlerExecutionChain handler = mapping.getHandler(request);
         if (handler != null) {
            return handler;
         }
      }
   }
   return null;
}

java复制代码@Override
@SuppressWarnings("deprecation")
public void afterPropertiesSet() {
    //配置
   this.config = new RequestMappingInfo.BuilderConfiguration();
   this.config.setUrlPathHelper(getUrlPathHelper());
   this.config.setPathMatcher(getPathMatcher());
   this.config.setSuffixPatternMatch(useSuffixPatternMatch());
   this.config.setTrailingSlashMatch(useTrailingSlashMatch());
   this.config.setRegisteredSuffixPatternMatch(useRegisteredSuffixPatternMatch());
   this.config.setContentNegotiationManager(getContentNegotiationManager());
    //这里是核心，会把所有controller注册进去
   super.afterPropertiesSet();
}

java复制代码@Override
public void afterPropertiesSet() {
   initHandlerMethods();
}

protected void initHandlerMethods() {
   for (String beanName : getCandidateBeanNames()) {
      if (!beanName.startsWith(SCOPED_TARGET_NAME_PREFIX)) {
      //这里会注册controller
         processCandidateBean(beanName);
      }
   }
   handlerMethodsInitialized(getHandlerMethods());
}

protected void processCandidateBean(String beanName) {
   Class<?> beanType = null;
   try {
      beanType = obtainApplicationContext().getType(beanName);
   }
   catch (Throwable ex) {
      if (logger.isTraceEnabled()) {
         logger.trace("Could not resolve type for bean '" + beanName + "'", ex);
      }
   }
   //这里的isHandler会判断是否有Controller或RequestMapping注解
   if (beanType != null && isHandler(beanType)) {
      //这里会注册controller，接着跟
      detectHandlerMethods(beanName);
   }
}

protected void detectHandlerMethods(Object handler) {
    //获取类型
   Class<?> handlerType = (handler instanceof String ?
         obtainApplicationContext().getType((String) handler) : handler.getClass());

   if (handlerType != null) {
      Class<?> userType = ClassUtils.getUserClass(handlerType);
      Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
            (MethodIntrospector.MetadataLookup<T>) method -> {
               try {
               //这里会把RequestMapping转换为RequestMappingInfo
                  return getMappingForMethod(method, userType);
               }
               catch (Throwable ex) {
                  throw new IllegalStateException("Invalid mapping on handler class [" +
                        userType.getName() + "]: " + method, ex);
               }
            });
      if (logger.isTraceEnabled()) {
         logger.trace(formatMappings(userType, methods));
      }
      methods.forEach((method, mapping) -> {
         Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
         //注册到mappingRegistry中，后面会根据request获取对应的HandlerMethod
         registerHandlerMethod(handler, invocableMethod, mapping);
      });
   }
}

java复制代码@Override
@Nullable
protected RequestMappingInfo getMappingForMethod(Method method, Class<?> handlerType) {
    //获取方法上的RequestMapping并且转换为RequestMappingInfo
   RequestMappingInfo info = createRequestMappingInfo(method);
   if (info != null) {
       //获取类上的RequestMapping并且转换为RequestMappingInfo（这里就是Controller上的RequestMapping）
      RequestMappingInfo typeInfo = createRequestMappingInfo(handlerType);
      if (typeInfo != null) {
          //将方法上的RequestMapping和类上的RequestMapping合并，这里会合并url
         info = typeInfo.combine(info);
      }
      String prefix = getPathPrefix(handlerType);
      if (prefix != null) {
         info = RequestMappingInfo.paths(prefix).options(this.config).build().combine(info);
      }
   }
   return info;
}

java复制代码protected void registerHandlerMethod(Object handler, Method method, T mapping) {
   //这里直接注册到mappingRegistry中，后面也直接从mappingRegistry获取
   this.mappingRegistry.register(mapping, handler, method);
}

public void register(T mapping, Object handler, Method method) {
   if (KotlinDetector.isKotlinType(method.getDeclaringClass())) {
      Class<?>[] parameterTypes = method.getParameterTypes();
      if ((parameterTypes.length > 0) && "kotlin.coroutines.Continuation".equals(parameterTypes[parameterTypes.length - 1].getName())) {
         throw new IllegalStateException("Unsupported suspending handler method detected: " + method);
      }
   }
   this.readWriteLock.writeLock().lock();
   try {
       //创建HandlerMethod
      HandlerMethod handlerMethod = createHandlerMethod(handler, method);
      validateMethodMapping(handlerMethod, mapping);
      this.mappingLookup.put(mapping, handlerMethod);

      List<String> directUrls = getDirectUrls(mapping);
      for (String url : directUrls) {
         this.urlLookup.add(url, mapping);
      }

      String name = null;
      if (getNamingStrategy() != null) {
         name = getNamingStrategy().getName(handlerMethod, mapping);
         addMappingName(name, handlerMethod);
      }

      CorsConfiguration corsConfig = initCorsConfiguration(handler, method, mapping);
      if (corsConfig != null) {
         this.corsLookup.put(handlerMethod, corsConfig);
      }
       //这里会添加到MappingRegistry中去
      this.registry.put(mapping, new MappingRegistration<>(mapping, handlerMethod, directUrls, name));
   }
   finally {
      this.readWriteLock.writeLock().unlock();
   }
}

java复制代码@Override
@Nullable
public final HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
    //这里获取真正的处理器，子类AbstractHandlerMethodMapping实现
   Object handler = getHandlerInternal(request);
   if (handler == null) {
      //没有的话，使用默认的
      handler = getDefaultHandler();
   }
   if (handler == null) {
      return null;
   }
   // 如果是beanName的话 从ioc容器中获取真正的实例
   if (handler instanceof String) {
      String handlerName = (String) handler;
      handler = obtainApplicationContext().getBean(handlerName);
   }
    //这里获取对应请求的拦截器链
   HandlerExecutionChain executionChain = getHandlerExecutionChain(handler, request);

   if (logger.isTraceEnabled()) {
      logger.trace("Mapped to " + handler);
   }
   else if (logger.isDebugEnabled() && !request.getDispatcherType().equals(DispatcherType.ASYNC)) {
      logger.debug("Mapped to " + executionChain.getHandler());
   }

   if (hasCorsConfigurationSource(handler) || CorsUtils.isPreFlightRequest(request)) {
      CorsConfiguration config = (this.corsConfigurationSource != null ? this.corsConfigurationSource.getCorsConfiguration(request) : null);
      CorsConfiguration handlerConfig = getCorsConfiguration(handler, request);
      config = (config != null ? config.combine(handlerConfig) : handlerConfig);
      executionChain = getCorsHandlerExecutionChain(request, executionChain, config);
   }

   return executionChain;
}

java复制代码@Override
protected HandlerMethod getHandlerInternal(HttpServletRequest request) throws Exception {
   String lookupPath = getUrlPathHelper().getLookupPathForRequest(request);
   request.setAttribute(LOOKUP_PATH, lookupPath);
   this.mappingRegistry.acquireReadLock();
   try {
      HandlerMethod handlerMethod = lookupHandlerMethod(lookupPath, request);
      return (handlerMethod != null ? handlerMethod.createWithResolvedBean() : null);
   }
   finally {
      this.mappingRegistry.releaseReadLock();
   }
}

@Nullable
protected HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request) throws Exception {
   List<Match> matches = new ArrayList<>();
   List<T> directPathMatches = this.mappingRegistry.getMappingsByUrl(lookupPath);
   if (directPathMatches != null) {
      addMatchingMappings(directPathMatches, matches, request);
   }
   if (matches.isEmpty()) {
      // No choice but to go through all mappings...
      addMatchingMappings(this.mappingRegistry.getMappings().keySet(), matches, request);
   }

   if (!matches.isEmpty()) {
      Match bestMatch = matches.get(0);
      if (matches.size() > 1) {
         Comparator<Match> comparator = new MatchComparator(getMappingComparator(request));
         matches.sort(comparator);
         bestMatch = matches.get(0);
         if (logger.isTraceEnabled()) {
            logger.trace(matches.size() + " matching mappings: " + matches);
         }
         if (CorsUtils.isPreFlightRequest(request)) {
            return PREFLIGHT_AMBIGUOUS_MATCH;
         }
         Match secondBestMatch = matches.get(1);
         if (comparator.compare(bestMatch, secondBestMatch) == 0) {
            Method m1 = bestMatch.handlerMethod.getMethod();
            Method m2 = secondBestMatch.handlerMethod.getMethod();
            String uri = request.getRequestURI();
            throw new IllegalStateException(
                  "Ambiguous handler methods mapped for '" + uri + "': {" + m1 + ", " + m2 + "}");
         }
      }
      request.setAttribute(BEST_MATCHING_HANDLER_ATTRIBUTE, bestMatch.handlerMethod);
      handleMatch(bestMatch.mapping, lookupPath, request);
      return bestMatch.handlerMethod;
   }
   else {
      return handleNoMatch(this.mappingRegistry.getMappings().keySet(), lookupPath, request);
   }
}

java复制代码protected HandlerExecutionChain getHandlerExecutionChain(Object handler, HttpServletRequest request) {
   HandlerExecutionChain chain = (handler instanceof HandlerExecutionChain ?
         (HandlerExecutionChain) handler : new HandlerExecutionChain(handler));
    //这里会拿到所有的拦截器，然后通过路径匹配到合适的拦截器
   String lookupPath = this.urlPathHelper.getLookupPathForRequest(request, LOOKUP_PATH);
   for (HandlerInterceptor interceptor : this.adaptedInterceptors) {
      if (interceptor instanceof MappedInterceptor) {
         MappedInterceptor mappedInterceptor = (MappedInterceptor) interceptor;
         if (mappedInterceptor.matches(lookupPath, this.pathMatcher)) {
            chain.addInterceptor(mappedInterceptor.getInterceptor());
         }
      }
      else {
         chain.addInterceptor(interceptor);
      }
   }
   return chain;
}

java复制代码//这里的ha就是RequestMappingHandlerAdapter类
//核心是RequestMappingHandlerAdapter类的handleInternal方法
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

java复制代码@Override
protected ModelAndView handleInternal(HttpServletRequest request,
      HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {

   ModelAndView mav;
   checkRequest(request);

   if (this.synchronizeOnSession) {
      HttpSession session = request.getSession(false);
      if (session != null) {
         Object mutex = WebUtils.getSessionMutex(session);
         synchronized (mutex) {
            //这里就是真正调用HandlerMethod的地方了
            mav = invokeHandlerMethod(request, response, handlerMethod);
         }
      }
      else {
          //这里就是真正调用HandlerMethod的地方了
         mav = invokeHandlerMethod(request, response, handlerMethod);
      }
   }
   else {
    //这里就是真正调用HandlerMethod的地方了
      mav = invokeHandlerMethod(request, response, handlerMethod);
   }

   if (!response.containsHeader(HEADER_CACHE_CONTROL)) {
      if (getSessionAttributesHandler(handlerMethod).hasSessionAttributes()) {
         applyCacheSeconds(response, this.cacheSecondsForSessionAttributeHandlers);
      }
      else {
         prepareResponse(response);
      }
   }

   return mav;
}

less复制代码@DS("postgresql")
@Mapper
public interface CtmAskForLeaveMapper extends BaseMapper<CtmAskForLeave> {

}

less复制代码@DS("mysql")
@Mapper
public interface CtmThirdAskForLeaveMapper extends BaseMapper<CtmThirdAskForLeave> {

}

java复制代码@Configuration
@MapperScan("mappper所在包")
public class MybatisPlusConfig {


    /**
     * 分页插件*/
    @Bean
    public PaginationInterceptor paginationInterceptor(){
        return new PaginationInterceptor();
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*/*.xml"));
        sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory());
        sqlSessionFactoryBean.setPlugins(new Interceptor[]{paginationInterceptor()});
        return sqlSessionFactoryBean.getObject();
    }


}

csharp复制代码/**
 * 处理数据
 * @return
 */
Boolean messageAskForLeave();

typescript复制代码@Override
public Boolean messageAskForLeave() {
    List<CtmThirdAskForLeave> ctmThirdAskForLeaves = ctmThirdAskForLeaveMapper.selectList(null);
}

go复制代码if (type == "A") {
    // A逻辑
} else if (type == "B") {
    // B逻辑
} else { 
    // 其他逻辑
}

arduino复制代码public interface BaseStrategy {

    public final static String KEY_CONCAT = "_";

    String getStrategyKey();
}

csharp复制代码public interface IStrategy  extends BaseStrategy {

    public final static String ESTATE_STRATEGY_KEY_PREFIX = IStrategy.class.getSimpleName() + KEY_CONCAT;

    void deal1();

    void deal2();
}