typescript复制代码@SpringBootApplication

public class Application{

 public static void main(String [] args){

 SpringApplication.run(Application.class,args);

 }

}

less复制代码@Configuration

@ConditionalOnClass(DataSource.class)

class MySQLAutoConfiguration {

 //...

}

less复制代码@Bean

@ConditionalOnBean(name="dataSource")

LocalContainerEntityManagerFactoryBean entityManagerFactory(){

 //...

}

@Bean

@ConditionalOnMissingBean

public MyBean myBean(){

 //...

}

less复制代码@Bean

@ConditionalOnProperty(name="alipay",havingValue="on")

Alipay alipay(){

 return new Alipay();

}

less复制代码@ConditionalOnResource(resources = "classpath:website.properties")

Properties addWebsiteProperties(){

 //...

}

less复制代码@ConditionalOnWebApplication

HealthCheckController healthCheckController(){

 //...

}

less复制代码@Bean

@ConditionalException("${localstore} && ${local == 'true'}")

LocalFileStore store(){

 //...

}

csharp复制代码@Conditioanl(CustomConditioanl.class)

CustomProperties addCustomProperties(){

 //...

}

css复制代码输入
["Solution", "shuffle", "reset", "shuffle"]
[[[1, 2, 3]], [], [], []]
输出
[null, [3, 1, 2], [1, 2, 3], [1, 3, 2]]

解释
Solution solution = new Solution([1, 2, 3]);
solution.shuffle();    // 打乱数组 [1,2,3] 并返回结果。任何 [1,2,3]的排列返回的概率应该相同。例如，返回 [3, 1, 2]
solution.reset();      // 重设数组到它的初始状态 [1, 2, 3] 。返回 [1, 2, 3]
solution.shuffle();    // 随机返回数组 [1, 2, 3] 打乱后的结果。例如，返回 [1, 3, 2]

Java复制代码class Solution {
    int[] nums;
    int n;
    Random random = new Random();
    public Solution(int[] _nums) {
        nums = _nums;
        n = nums.length;
    }
    public int[] reset() {
        return nums;
    }
    public int[] shuffle() {
        int[] ans = nums.clone();
        for (int i = 0; i < n; i++) {
            swap(ans, i, i + random.nextInt(n - i));
        }
        return ans;
    }
    void swap(int[] arr, int i, int j) {
        int c = arr[i];
        arr[i] = arr[j];
        arr[j] = c;
    }
}

hive复制代码hive> load data [local] inpath '数据的 path' [overwrite] into table student [partition (partcol1=val1,…)];

hive复制代码hive (default)> create table student_par(id string, name string) row format delimited fields terminated by '\t';

hive复制代码hive (default)> insert into table student_par values('1','wangwu'),('2','zhaoliu');

hive复制代码hive (default)> insert overwrite table student_par select id,name from student;

hive复制代码create table if not exists student3 as select id, name from student;

hive复制代码hive (default)> dfs -mkdir /student;
hive (default)> dfs -put /opt/module/hive-3.1.2/datas/student.txt /student;

hive复制代码hive (default)> create external table if not exists student3(id int, name string)
              > row format delimited fields terminated by '\t'
              > location '/student';

hive复制代码hive (default)> select * from student3;

hive复制代码hive (default)> import table student2 from '/user/hive/warehouse/export/student';

hive复制代码hive (default)> insert overwrite local directory '/opt/module/hive-3.1.2/datas/student01' select * from student;

hive复制代码hive (default)> insert overwrite local directory '/opt/module/hive-3.1.2/datas/student02' row format delimited fields terminated by '\t' select * from student;

hive复制代码hive (default)> insert overwrite directory '/student03' row format delimited fields terminated by '\t' select * from student;

hive复制代码hive (default)> dfs -get /user/hive/warehouse/student/student.txt /opt/module/data/export/student3.txt;

shell复制代码[moe@hadoop102 datas]$ hive -e 'select * from student;' > ./student4.txt

hive复制代码hive (default)> export table student to '/student5';

hive复制代码hive (default)> truncate table student;

txt复制代码SELECT [ALL | DISTINCT] select_expr, select_expr, ...
FROM table_reference
[WHERE where_condition]
[GROUP BY col_list]
[ORDER BY col_list]
[CLUSTER BY col_list
| [DISTRIBUTE BY col_list] [SORT BY col_list]
]
[LIMIT number]

txt复制代码10	ACCOUNTING	1700
20	RESEARCH	1800
30	SALES	1900
40	OPERATIONS	1700

txt复制代码7369	SMITH	CLERK	7902	1980-12-17	800.00		20
7499	ALLEN	SALESMAN	7698	1981-2-20	1600.00	300.00	30
7521	WARD	SALESMAN	7698	1981-2-22	1250.00	500.00	30
7566	JONES	MANAGER	7839	1981-4-2	2975.00		20
7654	MARTIN	SALESMAN	7698	1981-9-28	1250.00	1400.00	30
7698	BLAKE	MANAGER	7839	1981-5-1	2850.00		30
7782	CLARK	MANAGER	7839	1981-6-9	2450.00		10
7788	SCOTT	ANALYST	7566	1987-4-19	3000.00		20
7839	KING	PRESIDENT		1981-11-17	5000.00		10
7844	TURNER	SALESMAN	7698	1981-9-8	1500.00	0.00	30
7876	ADAMS	CLERK	7788	1987-5-23	1100.00		20
7900	JAMES	CLERK	7698	1981-12-3	950.00		30
7902	FORD	ANALYST	7566	1981-12-3	3000.00		20
7934	MILLER	CLERK	7782	1982-1-23	1300.00		10

hive复制代码hive (default)> select * from emp;
hive (default)> select empno,ename,job,mgr,hiredate,sal,comm,deptno from emp ;

hive复制代码hive (default)> select empno, ename from emp;

hive复制代码hive (default)> select ename AS name, deptno dn from emp;

hive复制代码hive (default)> select sal + 1 from emp;

hive复制代码hive (default)> select count(*) cnt from emp;

hive复制代码hive (default)> select max(sal) max_sal from emp;

hive复制代码hive (default)> select min(sal) min_sal from emp;

hive复制代码hive (default)> select sum(sal) sum_sal from emp;

hive复制代码hive (default)> select avg(sal) avg_sal from emp;

hive复制代码hive (default)> select * from emp limit 5;

hive复制代码hive (default)> select * from emp where sal >1000;

hive复制代码hive (default)> select * from emp where sal = 5000;

hive复制代码hive (default)> select * from emp where sal between 500 and 1000;

hive复制代码hive (default)> select * from emp where comm is null;

hive复制代码hive (default)> select * from emp where sal IN (1500, 5000);

hive复制代码hive (default)> select * from emp where sal>1000 and deptno=30;

hive复制代码hive (default)> select * from emp where sal>1000 or deptno=30;

hive复制代码hive (default)> select * from emp where deptno not IN(30, 20);

hive复制代码hive (default)> select t.deptno, avg(t.sal) avg_sal from emp t group by t.deptno;

hive复制代码hive (default)> select t.deptno, t.job, max(t.sal) max_sal from emp t group by t.deptno, t.job;

hive复制代码hive (default)> select deptno, avg(sal) from emp group by deptno;

hive复制代码hive (default)> select deptno, avg(sal) avg_sal from emp group by deptno having avg_sal > 2000;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno, d.dname from emp e inner join dept d on e.deptno = d.deptno;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno from emp e join dept d on e.deptno = d.deptno;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno from emp e join dept d on e.deptno = d.deptno;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno from emp e left join dept d on e.deptno = d.deptno;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno from emp e right join dept d on e.deptno = d.deptno;

hive复制代码hive (default)> select e.empno, e.ename, d.deptno from emp e full join dept d on e.deptno = d.deptno;

txt复制代码1700	Beijing
1800	London
1900	Tokyo

hive复制代码create table if not exists location(
loc int,
loc_name string
)
row format delimited fields terminated by '\t';

hive复制代码hive (default)> load data local inpath '/opt/module/hive-3.1.2/datas/location.txt' into table location;

hive复制代码hive (default)>SELECT e.ename, d.dname, l.loc_name FROM emp e JOIN dept d ON d.deptno = e.deptno JOIN location l ON d.loc = l.loc;

hive复制代码hive (default)> select empno, dname from emp, dept;

hive复制代码hive (default)> select ename, sal*2 twosal from emp order by twosal;

hive复制代码hive (default)> select ename, deptno, sal from emp order by deptno, sal;

hive复制代码hive (default)> set mapreduce.job.reduces=3;

hive复制代码hive (default)> set mapreduce.job.reduces;

hive复制代码hive (default)> select * from emp sort by deptno desc;

hive复制代码hive (default)> insert overwrite local directory '/opt/module/data/sortby-result' select * from emp sort by deptno desc;

hive复制代码hive (default)> set mapreduce.job.reduces=3;
hive (default)> insert overwrite local directory '/opt/module/data/distribute-result' select * from emp distribute by deptno sort by empno desc;

hive复制代码hive (default)> select * from emp cluster by deptno;
hive (default)> select * from emp distribute by deptno sort by deptno;

xml复制代码 <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>5.1.47</version>
       </dependency>
       <dependency>
           <groupId>c3p0</groupId>
           <artifactId>c3p0</artifactId>
           <version>0.9.1.2</version>
       </dependency>
       <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>druid</artifactId>
           <version>1.1.10</version>
       </dependency>
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.12</version>
           <scope>test</scope>
       </dependency>

java复制代码   @Test
//测试手动创建 c3p0数据源
    public void dataSourceTest() throws Exception {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUser("root");
        dataSource.setPassword("root");
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
    @Test
    public void druidTest() throws Exception{
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName("com.mysql.jdbc.Driver");
        druidDataSource.setUrl("jdbc:mysql://localhost:3306/test");
        druidDataSource.setUsername("root");
        druidDataSource.setPassword("root");
        DruidPooledConnection connection = druidDataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

properties复制代码jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.user=root
jdbc.password=root

java复制代码@Test  //测试c3p0数据源(使用properties配置文件)
    public void c3p0Test() throws Exception {
        ResourceBundle jdbc = ResourceBundle.getBundle("jdbc");
        String driver = jdbc.getString("jdbc.driver");
        String url = jdbc.getString("jdbc.url");
        String user = jdbc.getString("jdbc.user");
        String password = jdbc.getString("jdbc.password");
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(user);
        dataSource.setPassword(password);
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

xml复制代码      <bean id="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
          <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
          <property name="url" value="jdbc:mysql://localhost:3306/test"></property>
          <property name="username" value="root"></property>
          <property name="password" value="root"></property>
      </bean>

java复制代码    @Test
    public void testSpringContext() throws Exception {
        ApplicationContext app=new ClassPathXmlApplicationContext("applicationContext.xml");
        DruidDataSource druidDataSource = app.getBean(DruidDataSource.class);
        DruidPooledConnection connection = druidDataSource.getConnection();
        System.out.println(connection);
        connection.close();
​
    }

xml复制代码<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context.xsd">
     <context:property-placeholder location="classpath:jdbc.properties"/>
    <bean id="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
          <property name="driverClassName" value="${jdbc.driver}"></property>
          <property name="url" value="${jdbc.url}"></property>
          <property name="username" value="${jdbc.user}"></property>
          <property name="password" value="${jdbc.password}"></property>
      </bean>
</beans>

python复制代码def dianzan_guanzhu():
    now = datetime.datetime.now()
    name = "python萌新"
    print("%s name:%s" % (now, name))
    time.sleep(1)
    result = "好棒！" + name + " 关注雷学委,学会了开发知识！"
    print("%s result:%s" % (now, result))
    return result

python复制代码#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time : 2021/11/21 12:02 上午
# @Author : LeiXueWei
# @CSDN/Juejin/Wechat: 雷学委
# @XueWeiTag: CodingDemo
# @File : __init__.py.py
# @Project : hello

import threading
import datetime
import time


def dianzan_guanzhu():
    now = datetime.datetime.now()
    name = "python萌新"
    print("%s name:%s" % (now, name))
    time.sleep(1)
    result = "好棒！" + name + " 关注雷学委,学会了开发知识！"
    print("%s result:%s" % (now, result))
    return result


for i in range(3):
    mythread = threading.Thread(name="t-" + str(i), target=dianzan_guanzhu)
    print("mythread:", mythread)
    print("is_alive:", mythread.is_alive())
    mythread.start()
    print("is_alive:", mythread.is_alive())

python复制代码#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time : 2021/11/21 12:02 上午
# @Author : LeiXueWei
# @CSDN/Juejin/Wechat: 雷学委
# @XueWeiTag: CodingDemo
# @File : __init__.py.py
# @Project : hello
import random
import threading
import datetime
import time


def dianzan_guanzhu():
    thread_name = threading.current_thread().getName()
    now = datetime.datetime.now()
    print("线程启动了:", thread_name)
    name = "python萌新"+thread_name
    print("%s - %s name:%s" % (thread_name, now, name))
    time.sleep(1)
    result = "好棒！" + name + " 关注雷学委,学会了开发知识！"
    print("%s - %s result:%s" % (thread_name, now, result))
    return result


for i in range(3):
    mythread = threading.Thread(name="t-" + str(i), target=dianzan_guanzhu)
    print("mythread:", mythread)
    print("is_alive:", mythread.is_alive())
    mythread.start()
    ac = threading.active_count()
    print("active_count:", ac)

ini复制代码@Test
public void testPredicateAnd() {

    Predicate<String> letterLengthLimit = s -> s.length() > 5;
    Predicate<String> letterStartWith = s -> s.startsWith("gate");

    MICRO_SERVICE.stream().filter(
            letterLengthLimit.and(letterStartWith)
    ).forEach(System.out::println);
}

ini复制代码@Test
public void testPredicateOr() {

    Predicate<String> letterLengthLimit = s -> s.length() > 5;
    Predicate<String> letterStartWith = s -> s.startsWith("gate");

    MICRO_SERVICE.stream().filter(
            letterLengthLimit.or(letterStartWith)
    ).forEach(System.out::println);
}

typescript复制代码@Test
public void testPredicateNegate() {

    Predicate<String> letterStartWith = s -> s.startsWith("gate");
    MICRO_SERVICE.stream().filter(letterStartWith.negate()).forEach(System.out::println);
}

scss复制代码@Test
public void testPredicateIsEqual() {
    Predicate<String> equalGateway = s -> Predicate.isEqual("gateway").test(s);
    MICRO_SERVICE.stream().filter(equalGateway).forEach(System.out::println);
}

php复制代码/**
 * Returns an {@code Optional} describing the specified value, if non-null,
 * otherwise returns an empty {@code Optional}.
 *
 * @param <T> the class of the value
 * @param value the possibly-null value to describe
 * @return an {@code Optional} with a present value if the specified value
 * is non-null, otherwise an empty {@code Optional}
 */
public static <T> Optional<T> ofNullable(T value) {
    return value == null ? empty() : of(value);
}

typescript复制代码/**
 * Return the value if present, otherwise return {@code other}.
 *
 * @param other the value to be returned if there is no value present, may
 * be null
 * @return the value, if present, otherwise {@code other}
 */
public T orElse(T other) {
    return value != null ? value : other;
}

arduino复制代码public Predicate<ServerWebExchange> apply(PathRoutePredicateFactory.Config config) {
    final ArrayList<PathPattern> pathPatterns = new ArrayList();
    synchronized(this.pathPatternParser) {
        this.pathPatternParser.setMatchOptionalTrailingSeparator(config.isMatchOptionalTrailingSeparator());
        config.getPatterns().forEach((pattern) -> {
            PathPattern pathPattern = this.pathPatternParser.parse(pattern);
            pathPatterns.add(pathPattern);
        });
    }

    return new GatewayPredicate() {
        public boolean test(ServerWebExchange exchange) {
            PathContainer path = PathContainer.parsePath(exchange.getRequest().getURI().getRawPath());
            Optional<PathPattern> optionalPathPattern = pathPatterns.stream().filter((pattern) -> {
                return pattern.matches(path);
            }).findFirst();
            if (optionalPathPattern.isPresent()) {
                PathPattern pathPattern = (PathPattern)optionalPathPattern.get();
                PathRoutePredicateFactory.traceMatch("Pattern", pathPattern.getPatternString(), path, true);
                PathMatchInfo pathMatchInfo = pathPattern.matchAndExtract(path);
                ServerWebExchangeUtils.putUriTemplateVariables(exchange, pathMatchInfo.getUriVariables());
                return true;
            } else {
                PathRoutePredicateFactory.traceMatch("Pattern", config.getPatterns(), path, false);
                return false;
            }
        }

        public String toString() {
            return String.format("Paths: %s, match trailing slash: %b", config.getPatterns(), config.isMatchOptionalTrailingSeparator());
        }
    };
}