sql复制代码/* 例如：可以通过设置当前事务为查询 5 秒之前的数据状态来开启 Stale Read */
> SET TRANSACTION READ ONLY AS OF TIMESTAMP NOW() - INTERVAL 5 SECOND;
> SELECT * FROM T;

java复制代码public enum CodeEnum {

    // 根据业务需求进行添加
    SUCCESS(200,"处理成功"),
    ERROR_PATH(404,"请求地址错误"),
    ERROR_SERVER(505,"服务器内部发生错误");
    
    private int code;
    private String message;
    
    CodeEnum(int code, String message) {
        this.code = code;
        this.message = message;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

java复制代码public class R implements Serializable {

    private static final long serialVersionUID = 793034041048451317L;

    private int code;
    private String message;
    private Object data = null;

    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }

    public Object getData() {
        return data;
    }

    /**
     * 放入响应枚举
     */
    public R fillCode(CodeEnum codeEnum){
        this.setCode(codeEnum.getCode());
        this.setMessage(codeEnum.getMessage());
        return this;
    }

    /**
     * 放入响应码及信息
     */
    public R fillCode(int code, String message){
        this.setCode(code);
        this.setMessage(message);
        return this;
    }

    /**
     * 处理成功，放入自定义业务数据集合
     */
    public R fillData(Object data) {
        this.setCode(CodeEnum.SUCCESS.getCode());
        this.setMessage(CodeEnum.SUCCESS.getMessage());
        this.data = data;
        return this;
    }
}

java复制代码List<String> list = Arrays.asList("a", "b", "c");
// 创建一个顺序流
Stream<String> stream = list.stream();
// 创建一个并行流
Stream<String> parallelStream = list.parallelStream();

java复制代码int[] array={1,3,5,6,8};
IntStream stream = Arrays.stream(array);

java复制代码Stream<Integer> stream = Stream.of(1, 2, 3, 4, 5, 6);

Stream<Integer> stream2 = Stream.iterate(0, (x) -> x + 3).limit(4);
stream2.forEach(System.out::println); // 0 3 6 9

Stream<Double> stream3 = Stream.generate(Math::random).limit(3);
stream3.forEach(System.out::println);

vbnet复制代码3
6
9
0.8106623442686114
0.11554643727388458
0.1404645961428974

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(7, 6, 9, 3, 8, 2, 1);
        // 遍历输出符合条件的元素
        list.stream().filter(x -> x > 6).forEach(System.out::println);
        // 匹配第一个
        Optional<Integer> findFirst = list.stream().filter(x -> x > 6).findFirst();
        // 匹配任意（适用于并行流）
        Optional<Integer> findAny = list.parallelStream().filter(x -> x > 6).findAny();
        // 是否包含符合特定条件的元素
        boolean anyMatch = list.stream().anyMatch(x -> x < 6);
        System.out.println("匹配第一个值：" + findFirst.get());
        System.out.println("匹配任意一个值：" + findAny.get());
        System.out.println("是否存在大于6的值：" + anyMatch);
        
    }
}

vbnet复制代码7
9
8
匹配第一个值：7
匹配任意一个值：8
是否存在大于6的值：true

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(6, 7, 3, 8, 1, 2, 9);
        Stream<Integer> stream = list.stream();
        stream.filter(x -> x > 7).forEach(System.out::println);
    }
}

vbnet复制代码8
9

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<String> list = Arrays.asList("adnm", "admmt", "pot", "xbangd", "weoujgsd");
        Optional<String> max = list.stream().max(Comparator.comparing(String::length));
        System.out.println("最长的字符串：" + max.get());
    }
}

vbnet复制代码最长的字符串：weoujgsd

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(7, 6, 9, 4, 11, 6);
        // 自然排序
        Optional<Integer> max = list.stream().max(Integer::compareTo);
        // 自定义排序
        Optional<Integer> max2 = list.stream().max(new Comparator<Integer>() {
            @Override
            public int compare(Integer o1, Integer o2) {
                return o1.compareTo(o2);
            }
        });
        System.out.println("自然排序的最大值：" + max.get());
        System.out.println("自定义排序的最大值：" + max2.get());
    }
}

vbnet复制代码自然排序的最大值：11
自定义排序的最大值：11

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(7, 6, 4, 8, 2, 11, 9);
        long count = list.stream().filter(x -> x > 6).count();
        System.out.println("list中大于6的元素个数：" + count);
    }
}

vbnet复制代码list中大于6的元素个数：4

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        String[] strArr = { "abcd", "bcdd", "defde", "fTr" };
        List<String> strList = Arrays.stream(strArr).map(String::toUpperCase).collect(Collectors.toList());
        System.out.println("每个元素大写：" + strList);
        List<Integer> intList = Arrays.asList(1, 3, 5, 7, 9, 11);
        List<Integer> intListNew = intList.stream().map(x -> x + 3).collect(Collectors.toList());
        System.out.println("每个元素+3：" + intListNew);
    }
}

css复制代码每个元素大写：[ABCD, BCDD, DEFDE, FTR]
每个元素+3：[4, 6, 8, 10, 12, 14]

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<String> list = Arrays.asList("m,k,l,a", "1,3,5,7");
        List<String> listNew = list.stream().flatMap(s -> {
            // 将每个元素转换成一个stream
            String[] split = s.split(",");
            Stream<String> s2 = Arrays.stream(split);
            return s2;
        }).collect(Collectors.toList());
        System.out.println("处理前的集合：" + list);
        System.out.println("处理后的集合：" + listNew);
    }
}

css复制代码处理前的集合：[m,k,l,a, 1,3,5,7]
处理后的集合：[m, k, l, a, 1, 3, 5, 7]

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(1, 3, 2, 8, 11, 4);
        // 求和方式1
        Optional<Integer> sum = list.stream().reduce(Integer::sum);
        // 求和方式2
        Optional<Integer> sum2 = list.stream().reduce(Integer::sum);
        // 求和方式3
        Integer sum3 = list.stream().reduce(0, Integer::sum);
        // 求乘积
        Optional<Integer> product = list.stream().reduce((x, y) -> x * y);
        // 求最大值方式1
        Optional<Integer> max = list.stream().reduce((x, y) -> x > y ? x : y);
        // 求最大值写法2
        Integer max2 = list.stream().reduce(1, Integer::max);
        System.out.println("list求和：" + sum.get() + "," + sum2.get() + "," + sum3);
        System.out.println("list求积：" + product.get());
        System.out.println("list求和：" + max.get() + "," + max2);
    }
}

vbnet复制代码list求和：29,29,29
list求积：2112
list求和：11,11

Process finished with exit code 0

java复制代码public class Person {

    private String name;  // 姓名
    private int salary; // 薪资
    private int age; // 年龄
    private String sex; //性别
    private String area;  // 地区

    // 构造方法
    public Person(String name, int salary, int age,String sex,String area) {
        this.name = name;
        this.salary = salary;
        this.age = age;
        this.sex = sex;
        this.area = area;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getSalary() {
        return salary;
    }

    public void setSalary(int salary) {
        this.salary = salary;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getArea() {
        return area;
    }

    public void setArea(String area) {
        this.area = area;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", salary=" + salary +
                ", age=" + age +
                ", sex='" + sex + '\'' +
                ", area='" + area + '\'' +
                '}';
    }
}

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(1, 6, 3, 4, 6, 7, 9, 6, 20);
        List<Integer> listNew = list.stream().filter(x -> x % 2 == 0).collect(Collectors.toList());
        Set<Integer> set = list.stream().filter(x -> x % 2 == 0).collect(Collectors.toSet());
        List<Person> personList = new ArrayList<Person>();
        personList.add(new Person("Tom", 8900, 23, "male", "New York"));
        personList.add(new Person("Jack", 7000, 25, "male", "Washington"));
        personList.add(new Person("Lily", 7800, 21, "female", "Washington"));
        personList.add(new Person("Anni", 8200, 24, "female", "New York"));
        Map<?, Person> map = personList.stream().filter(p -> p.getSalary() > 8000)
                .collect(Collectors.toMap(Person::getName, p -> p));
        System.out.println("toList:" + listNew);
        System.out.println("toSet:" + set);
        System.out.println("toMap:" + map);
    }
}

ini复制代码toList:[6, 4, 6, 6, 20]
toSet:[4, 20, 6]
toMap:{Tom=Person{name='Tom', salary=8900, age=23, sex='male', area='New York'}, Anni=Person{name='Anni', salary=8200, age=24, sex='female', area='New York'}}

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Person> personList = new ArrayList<Person>();
        personList.add(new Person("Tom", 8900, 23, "male", "New York"));
        personList.add(new Person("Jack", 7000, 25, "male", "Washington"));
        personList.add(new Person("Lily", 7800, 21, "female", "Washington"));
        // 求总数
        long count = personList.size();
        // 求平均工资
        Double average = personList.stream().collect(Collectors.averagingDouble(Person::getSalary));
        // 求最高工资
        Optional<Integer> max = personList.stream().map(Person::getSalary).max(Integer::compare);
        // 求工资之和
        int sum = personList.stream().mapToInt(Person::getSalary).sum();
        // 一次性统计所有信息
        DoubleSummaryStatistics collect = personList.stream().collect(Collectors.summarizingDouble(Person::getSalary));
        System.out.println("员工总数：" + count);
        System.out.println("员工平均工资：" + average);
        System.out.println("员工最高工资：" + max.get());
        System.out.println("员工工资总和：" + sum);
        System.out.println("员工工资所有统计：" + collect);
    }
}

python复制代码员工总数：3
员工平均工资：7900.0
员工最高工资：8900
员工工资总和：23700
员工工资所有统计：DoubleSummaryStatistics{count=3, sum=23700.000000, min=7000.000000, average=7900.000000, max=8900.000000}

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Person> personList = new ArrayList<Person>();
        personList.add(new Person("Tom", 8900, 23, "male", "Washington"));
        personList.add(new Person("Jack", 7000, 25, "male", "Washington"));
        personList.add(new Person("Lily", 7800, 21, "female", "New York"));
        personList.add(new Person("Anni", 8200, 24, "female", "New York"));
        // 将员工按薪资是否高于8000分组
        Map<Boolean, List<Person>> part = personList.stream().collect(Collectors.partitioningBy(x -> x.getSalary() > 8000));
        // 将员工按性别分组
        Map<String, List<Person>> group = personList.stream().collect(Collectors.groupingBy(Person::getSex));
        // 将员工先按性别分组，再按地区分组
        Map<String, Map<String, List<Person>>> group2 = personList.stream().collect(Collectors.groupingBy(Person::getSex, Collectors.groupingBy(Person::getArea)));
        System.out.println("员工按薪资是否大于8000分组情况：" + part);
        System.out.println("员工按性别分组情况：" + group);
        System.out.println("员工按性别、地区：" + group2);
    }
}

css复制代码员工按薪资是否大于8000分组情况：{false=[Person{name='Jack', salary=7000, age=25, sex='male', area='Washington'}, Person{name='Lily', salary=7800, age=21, sex='female', area='New York'}], true=[Person{name='Tom', salary=8900, age=23, sex='male', area='Washington'}, Person{name='Anni', salary=8200, age=24, sex='female', area='New York'}]}
员工按性别分组情况：{female=[Person{name='Lily', salary=7800, age=21, sex='female', area='New York'}, Person{name='Anni', salary=8200, age=24, sex='female', area='New York'}], male=[Person{name='Tom', salary=8900, age=23, sex='male', area='Washington'}, Person{name='Jack', salary=7000, age=25, sex='male', area='Washington'}]}
员工按性别、地区：{female={New York=[Person{name='Lily', salary=7800, age=21, sex='female', area='New York'}, Person{name='Anni', salary=8200, age=24, sex='female', area='New York'}]}, male={Washington=[Person{name='Tom', salary=8900, age=23, sex='male', area='Washington'}, Person{name='Jack', salary=7000, age=25, sex='male', area='Washington'}]}}

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Person> personList = new ArrayList<Person>();
        personList.add(new Person("Tom", 8900, 23, "male", "New York"));
        personList.add(new Person("Jack", 7000, 25, "male", "Washington"));
        personList.add(new Person("Lily", 7800, 21, "female", "Washington"));
        String names = personList.stream().map(Person::getName).collect(Collectors.joining(","));
        System.out.println("所有员工的姓名：" + names);
        List<String> list = Arrays.asList("A", "B", "C");
        String string = list.stream().collect(Collectors.joining("-"));
        System.out.println("拼接后的字符串：" + string);
    }
}

css复制代码所有员工的姓名：Tom,Jack,Lily
拼接后的字符串：A-B-C

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        List<Person> personList = new ArrayList<Person>();
        personList.add(new Person("Sherry", 9000, 24, "female", "New York"));
        personList.add(new Person("Tom", 8900, 22, "male", "Washington"));
        personList.add(new Person("Jack", 9000, 25, "male", "Washington"));
        personList.add(new Person("Lily", 8800, 26, "male", "New York"));
        personList.add(new Person("Alisa", 9000, 26, "female", "New York"));
        // 按工资升序排序（自然排序）
        List<String> newList = personList.stream().sorted(Comparator.comparing(Person::getSalary)).map(Person::getName)
                .collect(Collectors.toList());
        // 按工资倒序排序
        List<String> newList2 = personList.stream().sorted(Comparator.comparing(Person::getSalary).reversed())
                .map(Person::getName).collect(Collectors.toList());
        // 先按工资再按年龄升序排序
        List<String> newList3 = personList.stream()
                .sorted(Comparator.comparing(Person::getSalary).thenComparing(Person::getAge)).map(Person::getName)
                .collect(Collectors.toList());
        // 先按工资再按年龄自定义排序（降序）
        List<String> newList4 = personList.stream().sorted((p1, p2) -> {
            if (p1.getSalary() == p2.getSalary()) {
                return p2.getAge() - p1.getAge();
            } else {
                return p2.getSalary() - p1.getSalary();
            }
        }).map(Person::getName).collect(Collectors.toList());
        System.out.println("按工资升序排序：" + newList);
        System.out.println("按工资降序排序：" + newList2);
        System.out.println("先按工资再按年龄升序排序：" + newList3);
        System.out.println("先按工资再按年龄自定义降序排序：" + newList4);
    }
}

css复制代码按工资升序排序：[Lily, Tom, Sherry, Jack, Alisa]
按工资降序排序：[Sherry, Jack, Alisa, Tom, Lily]
先按工资再按年龄升序排序：[Lily, Tom, Sherry, Jack, Alisa]
先按工资再按年龄自定义降序排序：[Alisa, Jack, Sherry, Tom, Lily]

Process finished with exit code 0

java复制代码public class StreamTest {

    public static void main(String[] args) {
        String[] arr1 = { "a", "b", "c", "d" };
        String[] arr2 = { "d", "e", "f", "g" };
        Stream<String> stream1 = Stream.of(arr1);
        Stream<String> stream2 = Stream.of(arr2);
        // concat:合并两个流 distinct：去重
        List<String> newList = Stream.concat(stream1, stream2).distinct().collect(Collectors.toList());
        // limit：限制从流中获得前n个数据
        List<Integer> collect = Stream.iterate(1, x -> x + 2).limit(10).collect(Collectors.toList());
        // skip：跳过前n个数据
        List<Integer> collect2 = Stream.iterate(1, x -> x + 2).skip(1).limit(5).collect(Collectors.toList());
        System.out.println("流合并：" + newList);
        System.out.println("limit：" + collect);
        System.out.println("skip：" + collect2);
    }
}

css复制代码流合并：[a, b, c, d, e, f, g]
limit：[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
skip：[3, 5, 7, 9, 11]

Process finished with exit code 0

java复制代码//需要查询的数据
List<Integer> numbers = Arrays.asList(3, 2, 2, 3, 7, 3, 5, 10, 6, 20, 30, 40, 50, 60, 100);
List<Integer> dataList = numbers.stream().sorted(Integer::compareTo).skip(0).limit(10).collect(Collectors.toList());
System.out.println(dataList.toString());

csharp复制代码[2, 2, 3, 3, 3, 5, 6, 7, 10, 20]

Process finished with exit code 0

java复制代码List<String> strings = Arrays.asList("abc", "", "bc", "efg", "abcd", "", "jkl");
// 采用并行计算方法，获取空字符串的数量
long count = strings.parallelStream().filter(String::isEmpty).count();
System.out.println(count);

java复制代码public static void main(String[] args) {
    List<Person> personList = new ArrayList<>();
    personList.add(new Person("Tom",7000,25,"male","安徽"));
    personList.add(new Person("Jack",8000,30,"female","北京"));
    personList.add(new Person("Lucy",9000,40,"male","上海"));
    personList.add(new Person("Airs",10000,40,"female","深圳"));
    Map<Integer, Person> collect = personList.stream().collect(Collectors.toMap(Person::getAge, v -> v, (k1, k2) -> k1));
    System.out.println(collect);
}

ini复制代码{40=Person{name='Lucy', salary=9000, age=40, sex='male', area='上海'}, 25=Person{name='Tom', salary=7000, age=25, sex='male', area='安徽'}, 30=Person{name='Jack', salary=8000, age=30, sex='female', area='北京'}}

Process finished with exit code 0

java复制代码public static <T, K, U>
    Collector<T, ?, Map<K,U>> toMap(Function<? super T, ? extends K> keyMapper,
                                    Function<? super T, ? extends U> valueMapper,
                                    BinaryOperator<U> mergeFunction) {
    return toMap(keyMapper, valueMapper, mergeFunction, HashMap::new);
}

http复制代码Authorization: Basic emx0OnpsdA==

java复制代码public interface Calculator {    /**     * 把传进来的所有numbers 做求和处理     *     * @param numbers     * @return 总和     */    long sumUp(long[] numbers);}

java复制代码public class ForLoopCalculator implements Calculator {    @Override    public long sumUp(long[] numbers) {        long total = 0;        for (long i : numbers) {            total += i;        }        return total;    }}

java复制代码    public static void main(String[] args) {        long[] numbers = LongStream.rangeClosed(1, 10000000).toArray();        Instant start = Instant.now();        Calculator calculator = new ForLoopCalculator();        long result = calculator.sumUp(numbers);        Instant end = Instant.now();        System.out.println("耗时：" + Duration.between(start, end).toMillis() + "ms");        System.out.println("结果为：" + result);     }输出：耗时：10ms结果为：50000005000000

java复制代码public class ExecutorServiceCalculator implements Calculator {    private int parallism;    private ExecutorService pool;    public ExecutorServiceCalculator() {        parallism = Runtime.getRuntime().availableProcessors(); // CPU的核心数 默认就用cpu核心数了        pool = Executors.newFixedThreadPool(parallism);    }    //处理计算任务的线程    private static class SumTask implements Callable<Long> {        private long[] numbers;        private int from;        private int to;        public SumTask(long[] numbers, int from, int to) {            this.numbers = numbers;            this.from = from;            this.to = to;        }        @Override        public Long call() {            long total = 0;            for (int i = from; i <= to; i++) {                total += numbers[i];            }            return total;        }    }    @Override    public long sumUp(long[] numbers) {        List<Future<Long>> results = new ArrayList<>();        // 把任务分解为 n 份，交给 n 个线程处理   4核心 就等分成4份呗        // 然后把每一份都扔个一个SumTask线程 进行处理        int part = numbers.length / parallism;        for (int i = 0; i < parallism; i++) {            int from = i * part; //开始位置            int to = (i == parallism - 1) ? numbers.length - 1 : (i + 1) * part - 1; //结束位置            //扔给线程池计算            results.add(pool.submit(new SumTask(numbers, from, to)));        }        // 把每个线程的结果相加，得到最终结果 get()方法 是阻塞的        // 优化方案：可以采用CompletableFuture来优化  JDK1.8的新特性        long total = 0L;        for (Future<Long> f : results) {            try {                total += f.get();            } catch (Exception ignore) {            }        }        return total;    }}

java复制代码    public static void main(String[] args) {        long[] numbers = LongStream.rangeClosed(1, 10000000).toArray();        Instant start = Instant.now();        Calculator calculator = new ExecutorServiceCalculator();        long result = calculator.sumUp(numbers);        Instant end = Instant.now();        System.out.println("耗时：" + Duration.between(start, end).toMillis() + "ms");        System.out.println("结果为：" + result); // 打印结果500500    }输出：耗时：30ms结果为：50000005000000

java复制代码public class ForkJoinCalculator implements Calculator {    private ForkJoinPool pool;    //执行任务RecursiveTask：有返回值  RecursiveAction：无返回值    private static class SumTask extends RecursiveTask<Long> {        private long[] numbers;        private int from;        private int to;        public SumTask(long[] numbers, int from, int to) {            this.numbers = numbers;            this.from = from;            this.to = to;        }        //此方法为ForkJoin的核心方法：对任务进行拆分  拆分的好坏决定了效率的高低        @Override        protected Long compute() {            // 当需要计算的数字个数小于6时，直接采用for loop方式计算结果            if (to - from < 6) {                long total = 0;                for (int i = from; i <= to; i++) {                    total += numbers[i];                }                return total;            } else { // 否则，把任务一分为二，递归拆分(注意此处有递归)到底拆分成多少分 需要根据具体情况而定                int middle = (from + to) / 2;                SumTask taskLeft = new SumTask(numbers, from, middle);                SumTask taskRight = new SumTask(numbers, middle + 1, to);                taskLeft.fork();                taskRight.fork();                return taskLeft.join() + taskRight.join();            }        }    }    public ForkJoinCalculator() {        // 也可以使用公用的线程池 ForkJoinPool.commonPool()：        // pool = ForkJoinPool.commonPool()        pool = new ForkJoinPool();    }    @Override    public long sumUp(long[] numbers) {        Long result = pool.invoke(new SumTask(numbers, 0, numbers.length - 1));        pool.shutdown();        return result;    }}输出：耗时：390ms结果为：50000005000000

java复制代码    public static void main(String[] args) {        Instant start = Instant.now();        long result = LongStream.rangeClosed(0, 10000000L).parallel().reduce(0, Long::sum);        Instant end = Instant.now();        System.out.println("耗时：" + Duration.between(start, end).toMillis() + "ms");        System.out.println("结果为：" + result); // 打印结果500500    }输出：耗时：130ms结果为：50000005000000

sql复制代码mysql> show engines;

sql复制代码mysql> show variables like '%storage_engine%';

sql复制代码show table status like "table_name" ;

properties复制代码query_cache_type=1
query_cache_size=600000

properties复制代码set global  query_cache_type=1;
set global  query_cache_size=600000;

sql复制代码select sql_no_cache count(*) from usr;

sql复制代码# 开启一个事务
START TRANSACTION;
# 多条 SQL 语句
SQL1,SQL2...
## 提交事务
COMMIT;

sql复制代码mysql> SELECT @@tx_isolation;
+-----------------+
| @@tx_isolation  |
+-----------------+
| REPEATABLE-READ |
+-----------------+

dart复制代码import 'dart:io';
import 'dart:isolate';

main() async {
  print(DateTime.now().toString() + ' 开始');

  //这是一个接收端口,可以理解成我的手机
  ReceivePort receivePort = new ReceivePort();

  //安排三个妹妹出去旅行,让她们牢记我的手机号
  await Isolate.spawn(travelToBeijing, receivePort.sendPort);
  await Isolate.spawn(travelToShanghai, receivePort.sendPort);
  await Isolate.spawn(travelToGuangzhou, receivePort.sendPort);

  //我就在手机上，等待他们的消息
  receivePort.listen((message) {
    print(message);
  });

  print(DateTime.now().toString() + ' 结束');
}

void travelToBeijing(SendPort sendPort) {
  sleep(Duration(seconds: 3));
  sendPort.send(DateTime.now().toString() + ' 我是妹妹1，我在北京了');
}

void travelToShanghai(SendPort sendPort) {
  sleep(Duration(seconds: 3));
  sendPort.send(DateTime.now().toString() + ' 我是妹妹2，我在上海了');
}

void travelToGuangzhou(SendPort sendPort) {
  sleep(Duration(seconds: 3));
  sendPort.send(DateTime.now().toString() + ' 我是妹妹3，我在广州了');
}

bash复制代码2021-07-01 15:40:38.132122 开始
2021-07-01 15:40:38.295683 结束
2021-07-01 15:40:41.200316 我是妹妹1，我在北京了
2021-07-01 15:40:41.248851 我是妹妹2，我在上海了
2021-07-01 15:40:41.296737 我是妹妹3，我在广州了

dart复制代码import 'dart:io';
import 'dart:isolate';

class MultiTask {
  static void run(
      {List<TaskItem> taskList,
      Function taskFunc,
      Function onCompletedItem,
      Function onCompletedAll}) async {
    ReceivePort receivePort = new ReceivePort();

    Map<String, Isolate> mapParam = {};
    for (int i = 0; i < taskList.length; i++) {
      TaskItem taskItem = taskList[i];
      mapParam[taskItem.key] = await Isolate.spawn(
          taskFunc, TaskMessage(receivePort.sendPort, taskItem));
    }

    List<TaskRes> taskResList = [];
    receivePort.listen((message) async {
      TaskRes taskRes = message as TaskRes;
      if (null != onCompletedItem) await onCompletedItem(taskRes);
      taskResList.add(taskRes);
      mapParam[taskRes.key].kill();
      if (taskResList.length == taskList.length) {
        receivePort.close();
        if (null != onCompletedAll) await onCompletedAll(taskResList);
      }
    });
  }
}

class TaskMessage {
  SendPort sendPort;
  TaskItem taskItem;
  TaskMessage(this.sendPort, this.taskItem);
}

class TaskItem {
  String key;
  String param;

  TaskItem(this.key, this.param);
}

class TaskRes {
  String key;
  String res;

  TaskRes(this.key, this.res);
}

dart复制代码import 'dart:io';
import 'dart:isolate';
import 'MultiTask.dart';

main() async {
  List<TaskItem> taskList = [
    TaskItem('1', 'param1'),
    TaskItem('2', 'param2'),
    TaskItem('3', 'param1'),
    TaskItem('4', 'param2'),
    TaskItem('5', 'param1'),
    TaskItem('6', 'param2'),
    TaskItem('7', 'param1'),
    TaskItem('8', 'param2'),
    TaskItem('9', 'param1'),
    TaskItem('0', 'param2'),
  ];

  print(DateTime.now());

  MultiTask.run(
    taskList: taskList,
    taskFunc: taskFunc,
    onCompletedItem: (TaskRes taskRes) =>
        print(DateTime.now().toString() + '_' + taskRes.res),
    onCompletedAll: (List<TaskRes> taskResList) =>
        print(DateTime.now().toString() + '_onCompletedAll'),
  );
}

void taskFunc(TaskMessage taskMessage) async {
  sleep(Duration(seconds: 3));

  String res = 'onCompletedItem is ok';

  taskMessage.sendPort.send(TaskRes(taskMessage.taskItem.key, res));
}

yaml复制代码2021-07-01 15:50:54.862973
2021-07-01 15:50:57.924675_onCompletedItem is ok
2021-07-01 15:50:57.954982_onCompletedItem is ok
2021-07-01 15:50:57.986042_onCompletedItem is ok
2021-07-01 15:50:58.021282_onCompletedItem is ok
2021-07-01 15:50:58.053387_onCompletedItem is ok
2021-07-01 15:50:58.088492_onCompletedItem is ok
2021-07-01 15:50:58.121968_onCompletedItem is ok
2021-07-01 15:50:58.157117_onCompletedItem is ok
2021-07-01 15:50:58.190835_onCompletedItem is ok
2021-07-01 15:50:58.229044_onCompletedItem is ok
2021-07-01 15:50:58.241011_onCompletedAll

ts复制代码// 用户信息
interface UserInfo {
  // 来源渠道
  from: { type: '老用户邀请', fromUserId: string }
    | { type: '推广链接', url: string }
    | { type: '直接进入' },
  // 注册时间
  createTime: Date
}

ts复制代码export interface ReqHello {
  name: string;
}

export interface ResHello {
  reply: string;
}

ts复制代码import { ApiCall } from "tsrpc";

export async function ApiHello(call: ApiCall<ReqHello, ResHello>) {
  call.succ({
    reply: 'Hello, ' + call.req.name
  });
}

ts复制代码let ret = await client.callApi('Hello', {
    name: 'World'
});
console.log(ret); // { isSucc: true, res: { reply: 'Hello, World' } }

shell复制代码npx create-tsrpc-app@latest

python复制代码# !/usr/bin/python3
import threading
import uuid
from tkinter import *
from tkinter import filedialog, messagebox

import cv2
from PIL import ImageTk, Image


class MY_GUI():

    def __init__(self, init_window_name):
        self.init_window_name = init_window_name
        self.out_frame = None
        self.in_frame = None

    # 绘制窗口
    def set_init_window(self):
        self.init_window_name.title("图片处理")  # 窗口名
        self.init_window_name.geometry('950x681+10+10')

        self.input_label = Label(self.init_window_name, text="路径：")
        self.input_label.place(x=0, y=0, width=80, height=30)
        self.input_path = Entry(self.init_window_name)
        self.input_path.place(x=80, y=0, width=850, height=30)

        self.init_data_label = Label(self.init_window_name, text="修复前")
        self.init_data_label.place(x=0, y=60, width=80, height=30)
        self.result_data_label = Label(self.init_window_name, text="修复后")
        self.result_data_label.place(x=550, y=60, width=80, height=30)

        self.in_img_button = Button(self.init_window_name, text="选择图片", bg="lightblue", width=10,
                                    command=self.select_in_frame)
        self.in_img_button.place(x=400, y=100, width=150, height=30)

        self.degree_label = Label(self.init_window_name, text="修复程度（1-10）")
        self.degree_label.place(x=400, y=150, width=150, height=30)
        self.degree_input = Spinbox(self.init_window_name, from_=1, to=10)  # 调用内部方法  加()为直接调用
        self.degree_input.place(x=400, y=180, width=150, height=30)
        
        self.repair_button = Button(self.init_window_name, text="修复", bg="lightblue", width=10,
                                    command=self.access_pixels)
        self.repair_button.place(x=400, y=230, width=150, height=30)
        self.d_img_button = Button(self.init_window_name, text="保存", bg="lightblue", width=10,
                                   command=self.d_img)
        self.d_img_button.place(x=400, y=280, width=150, height=30)

    def select_in_frame(self):
        path = filedialog.askopenfilename()
        if path is None or path == '':
            messagebox.showinfo("提示", "请选择图片")
            return
        self.input_path.delete(0, END)
        self.input_path.insert(0, path)
        frame = cv2.imread(path)
        self.in_frame = frame

    # 这里就修复图片的代码了
    def access_pixels(self):
        if self.in_frame is None:
            messagebox.showinfo("提示", "请选择图片")
            return
        degreeStr = self.degree_input.get()
        if degreeStr is None or degreeStr == '':
            degreeStr = '0'

        degree = int(degreeStr)
        if degree < 1:
            degree = 1
        elif degree > 10:
            degree = 10

        frame = self.in_frame.copy()

        print(frame.shape)  # shape内包含三个元素：按顺序为高、宽、通道数
        height = frame.shape[0]
        weight = frame.shape[1]
        channels = frame.shape[2]

        showImgHeight = int(height / (weight / 400))
        # 这里是转换rgb 不然 保存下来会变色    
        b1, g1, r1 = cv2.split(self.in_frame.copy())
        rgb_img1 = cv2.merge([r1, g1, b1])
        im = Image.fromarray(cv2.resize(rgb_img1, (400, showImgHeight)))
        imgtk = ImageTk.PhotoImage(image=im)

        self.before2_img = Label(self.init_window_name, image=imgtk).place(x=0, y=90, width=400,
                                                                           height=showImgHeight)
        print("weight : %s, height : %s, channel : %s" % (weight, height, channels))
        for row in range(height):  # 遍历高
            for col in range(weight):  # 遍历宽
                for c in range(channels):  # 便利通道
                    pv = frame[row, col, c]
                    # 这里是判断是不是小黑点
                    if pv > 23 * (11 - degree):
                        # 这里就是计算增加白色 原颜色+修复程度*10,防止太白 颜色都一样
                        if (pv + degree * 10) > 255:
                            frame[row, col, c] = 255
                        else:
                            frame[row, col, c] = (pv + degree * 10)
                    # 这里是判断黑色，是不是需要更黑一些
                    if pv < degree * 15:
                        frame[row, col, c] = 0

        self.out_frame = frame
        b, g, r = cv2.split(self.out_frame.copy())
        rgb_img = cv2.merge([r, g, b])
        im2 = Image.fromarray(cv2.resize(rgb_img, (400, showImgHeight)))
        imgtk2 = ImageTk.PhotoImage(image=im2)
        self.img2 = Label(self.init_window_name, image=imgtk2).place(x=550, y=90, width=400, height=showImgHeight)
        self.img2.place()

    def d_img(self):
        if self.out_frame is None:
            messagebox.showinfo("提示", "请先修复图片")
            return
        path = filedialog.askdirectory()
        if path is None or path == '':
            messagebox.showinfo("提示", "请选择输出路径")
            return
        savepath = path + "/repair-" + str(uuid.uuid4()) + ".png"
        cv2.imwrite(savepath, self.out_frame)


if __name__ == '__main__':
    init_window = Tk()
    ZMJ_PORTAL = MY_GUI(init_window)
    ZMJ_PORTAL.set_init_window()
    init_window.mainloop()