qq_38522268的博客

xxl支持多种路由策略。路由策略针对同一个job在不同group运行的策略,当同时启动多个同名的执行器例子时，这个执行器就有多个，如下：这样这个xxl-job-executor-sample下就有两个进程了，配置这个group下的的job的路由策略：具体策略详见com.xxl.job.admin.core.route.ExecutorRouteStrategyEnumFIRST(I18nUtil.getString("jobconf_route_first"), new Executo

ThreadLocal是做线程本地存储，ThreadLocal为变量在每个线程中都创建了一个副本，每个线程可以访问自己内部的副本变量。举个ThreadLocal的例子public class ThreadLocalTest { private static ThreadLocal<Integer> threadLocal = new ThreadLocal<>(); public static void main(String[] args) {

1，下载jdk-8u221-linux-x64.tar.gz文件2，解压tar -zxvf jdk-8u221-linux-x64.tar.gz -C ~/app/3，配置环境参数vi ~/.bash_profile添加路径：export JAVA_HOME=/home/hadoop/app/jdk1.8.0_221export PATH=$JAVA_HOME/bin:$PATH4，刷新权限source~/.bash_profile5，用java和jav.

通过SpringApplication的类加载器获取System.out.println(SpringApplication.class.getClassLoader().getResource("META-INF/spring.factories"));输出：jar:file:/D:/maven/org/springframework/boot/spring-boot/2.2.0....

class Test{ public static int re(){ return new Random().nextInt(7)+1; } public static int re1(){ int i=re()-1; int j=re()-1; i=i*7+j;//i的范围0-48 /...

第一种直接在@Controller类下的方法里使用response.addHeader("Access-Control-Allow-Origin", "*");response.setHeader("Content-Type", "application/json;charset=UTF-8");如下：@GetMapping("/font")@ResponseBodypu...

二叉树类public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; }}前序：public class Solution { private List<Integer> list=n...

二叉树类public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; }}前序：public class Solution { public List<Integer> preorde...

PriorityQueue默认最小堆PriorityQueue priorityQueue=new PriorityQueue();priorityQueue.add(1);priorityQueue.add(2);System.out.println(priorityQueue.peek());输出1改成PriorityQueue priorityQueue=new Pr...

首先，引入gson依赖<dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId></dependency>下面是我对json进行一些测试public static void main(Stri...

使用java.util下的ArraysArrays.asList("1","2")

public class MyThread extends Thread { volatile boolean keepRunning = true; int count = 0;//成员变量 public void run() { System.out.println(getName() + "是一个Thread线程："); Syste...

第一种public sychronized void test(){}第二种private final Object lock=new Object();public void test(int i){sychronized (lock){if(i<0){lock.wait();}lock.notifyAll();}}两种方法都能实现方...

比较的是两个字符串时，如果字符串相同则返回0；如果按照字典排序，第一个字符串比第二个字符串靠前，就返回负值。public class Test { public static <T extends Comparable<T>> T maximum(T x, T y, T z) { T max = x; if (y.c...

public class Reflection { public static void main(String[] args){ //表示基本类型 Class c=int.class; System.out.println(c.isPrimitive()); System.out.println(c.getName());...

import java.util.InputMismatchException;import java.util.Scanner;public class TestException { public static void main(String[] args) { int a = 1; int b = 0; try ...

下面的方法是将nums里的元素频率最高的前k个元素存放到List里返回public List<Integer> top(int[] nums, int k) { HashMap<Integer, Integer> map = new HashMap<>(); for (int i : nums) { int count = m...

public class MaxHeap<E extends Comparable<E>> { private ArrayList<E> data; private MaxHeap(int capacity) { data = new ArrayList<>(capacity); } privat...

volatile关键的先行发生于后面这个变量的读操作public class Demo { private volatile static boolean shutdown; public static void main(String[] args) throws InterruptedException { Runnable runnable=()-&g...

Object.wait()主要在sychronized方法或者sychronized块中使用，使用该方法。当前线程进入waitset中，释放掉锁资源，直到被notify()方法被唤醒，进入锁池中竞争被加锁的资源Thread.sleep()当前线程让出cpu资源，不会影响锁，能够在程序的任何地方使用Thread.join()A,B两个线程 如果B.join(),而此时A线程没有...

第一种，通过 Integer.bitCount(index) 方法public int[] countBits(int num) { int[] memo = new int[num + 1]; int index = 0; while (index <= num) { memo[index] = Integer.bitCount(index);...

依赖：<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix</artifactId></dependency><!--dashboar...

feign的server和client都要引入feign依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> <version>...

lab:for (int i = 0; i < 10; i++) { for (int j = 0; j < 10; j++) { System.out.println("i="+"+i;"+"j="+j); if(j==3){ break lab; } }}

1配置config-server实现创建一个eureka client 见https://blog.youkuaiyun.com/qq_38522268/article/details/98465868添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifac...

添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> <version>1.4.2.RELEASE</version&...

第一种：使用RestTemplateRestTemplate restTemplate = new RestTemplate();//http://115.28.179.114:8885/String reponse = restTemplate.getForObject("http://www.baidu.com", String.class);log.info(reponse);...

添加配置spring: application: name: name注意spring不要有多个，比如spring: application: name: namespring: datasource: driver-class-name: com.mysql.jdbc.Driver会显示应用名UNKNOWN，应sprin...

启动类加注解@EnableDiscoveryClient@SpringBootApplication@EnableDiscoveryClientpublic class ClientApplication { public static void main(String[] args) { SpringApplication.run(ClientAppli...

启动类上加注解@EnableEurekaServer@SpringBootApplication@EnableEurekaServerpublic class EurekaApplication { public static void main(String[] args) { SpringApplication.run(EurekaApplication....

最简单的递归便宜方程为LCS(m,n)：求s1[0...m] 和s2[0...n]的最长公共子序列changdu偏移状态：s1[m] ==s2[n]?1+LCS(m-1,n-1):max(LCS(m-1,n),LCS(m,n-1))详细代码： public class Wigglemaxlength { private char[] s1; p...

首先我的配置是按照流程来的，只要把tomcat里的配置改成除443端口外的其他端口，再用https://域名:端口，可以正常访问但是使用https://域名:443时，浏览器上登录tomcat的开启页面，多次刷新，大多数显示页面连接被重置，也会有成功进入tomcat的时候，频率不高我又使用jmeter进行测试，返回的信息报错java.net.SocketException: Connec...

AtomicStampedReference能解决CAS的ABA问题，下面是这个类的简单使用public class ConcurrencyAutomicTest { //initialRef初始值，initialStamp版本号 private static AtomicStampedReference atomicStampedReference=new AtomicSt...

public class ConcurrencyAutomicTest8 { private static AtomicLongArray atomicLongArray=new AtomicLongArray(10); public static void main(String[] args){ //给数组下标为1的数组赋值2 atomicLo...

这里是Comparable和Comparator的实际使用我用java提供的最小堆结构PriorityQueue，并对给定的一个非空的整数数组，计算频率前k高的元素int[] nums = {-1, 1, -1, 1,-1, 2, 3};int k = 2;输出1 -1首先使用Comparablepublic class MySolution { privat...

接口public interface MyComparator<T> { T compare(T o1, T o2);}测试类public class TestMyComparator<T> { private MyComparator<T> comparator; private T[] data; publ...

char的引用类型是Character

将Set转成ArrayList在使用get()方法public static void main(String[] args){ Set<String> set1=new HashSet<>(); set1.add("1"); List<String> list=new ArrayList<>(set1); St...

一个字符串1_1_1_1我想获取第一个"_"后的字符串String str = "1_1_1_1";int index = str.indexOf("_");String newStr = str.substring(index + 1);System.out.println(newStr);输出：1_1_1第二个"_"后的字符串String str = "1_1...

下类有一个静态方法，一个非静态方法public class Msym { public static void test(String[] arg){ for (String string : arg) { System.out.println(string); } } public static void t...