基于SpringBoot多线程@Async的使用体验
作者：金陵砍柴人 发布时间：2021-07-15 04:47:04
多线程@Async的使用体验
场景
导入：可以将大批量的数据insert操作采用多线程的方式并行执行
第三方服务的接口调用：由于存在个别第三方服务调用比较耗时的场景，此时就可以与自身服务的逻辑并行执行
简而言之：接口中部份业务逻辑可以通过并行的方式来优化接口性能
1.线程池配置
@Configuration
@EnableAsync
public class TaskPoolConfig {
@Bean("taskExecutor") // bean 的名称，默认为首字母小写的方法名
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
//核心线程数（CPU核心数+1）
executor.setCorePoolSize(10);
//最大线程数（2*CPU核心数+1）
executor.setMaxPoolSize(20);
//缓冲队列数
executor.setQueueCapacity(200);
//允许线程空闲时间（单位：默认为秒）
executor.setKeepAliveSeconds(60);
//线程池名前缀
executor.setThreadNamePrefix("sub-thread-");
// 增加 TaskDecorator 属性的配置
executor.setTaskDecorator(new ContextDecorator());
// 线程池对拒绝任务的处理策略:CallerRunsPolicy：不在新线程中执行任务，而是由调用者所在的线程来执行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
executor.initialize();
return executor;
}
}
2.子父线程之间共享一个Request的配置方案
1.实现TaskDecorator接口
/**
* 子线程装饰器
*
* @author Da Shuai
* @date 2021-06-10 18:28:17
*/
public class SubThreadTaskDecorator implements TaskDecorator {
@Override
public Runnable decorate(Runnable runnable) {
RequestAttributes context = RequestContextHolder.currentRequestAttributes();
return () -> {
try {
RequestContextHolder.setRequestAttributes(context);
runnable.run();
} finally {
RequestContextHolder.resetRequestAttributes();
}
};
}
}
2.之前的线程池配置加如下代码使其生效
// 增加 TaskDecorator 属性的配置
executor.setTaskDecorator(new ContextDecorator());
3.阻塞主线程，等待所有子线程执行完毕后继续执行主线程
1.CountDownLatch
思路：
实例化CountDownLatch对象，同时传入x（线程数量：这个数量必须等于子线程数量）进行构造
每个子线程执行完毕后会调用countDown()方法
子线程逻辑后方调用await()方法
这样线程计数器为0之前，主线程就一直处于pending状态
主线程逻辑
new CountDownLatch(X)
latch.await()
@Override
@Transactional
public void importExcel(File file) {
CountDownLatch latch = new CountDownLatch(3);
for (int i = 0; i < 3; i++) {
VoteDO voteDO = new VoteDO();
voteDO.setTitle(i + "");
asyncManager.asyncSaveVote(voteDO);
}
//System.out.println(1/0);
try {
latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
子线程逻辑
latch.countDown()
@Override
@Async
public void asyncSaveVote(VoteDO voteDO, CountDownLatch latch) {
log.info("当前线程为 {}，休眠10s开始", Thread.currentThread().getName());
try {
Thread.sleep(10000L);
} catch (InterruptedException e) {
e.printStackTrace();
}
log.info("当前线程为 {}，休眠10s结束", Thread.currentThread().getName());
log.info("当前线程为 {}，保存开始", Thread.currentThread().getName());
voteDO.setDesc(Thread.currentThread().getName());
voteDao.insert(voteDO);
latch.countDown();
log.info("当前线程为 {}，保存结束", Thread.currentThread().getName());
}
日志
2021-06-11 16:31:08.653 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : ===============请求内容===============
2021-06-11 16:31:08.653 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : 请求地址:http://localhost:8080/api/import
2021-06-11 16:31:08.653 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : 请求方式:POST
2021-06-11 16:31:08.655 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : 请求类方法:com.zhdj.controller.ImportController.importExcel
2021-06-11 16:31:08.655 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : 请求类方法参数:[org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile@42c3f403]
2021-06-11 16:31:08.655 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : ===============请求内容===============
2021-06-11 16:31:08.676 INFO 27516 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2021-06-11 16:31:08.894 INFO 27516 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2021-06-11 16:31:08.921 INFO 27516 --- [ sub-thread-3] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-3，休眠10s开始
2021-06-11 16:31:08.921 INFO 27516 --- [ sub-thread-1] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-1，休眠10s开始
2021-06-11 16:31:08.921 INFO 27516 --- [ sub-thread-2] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-2，休眠10s开始
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-2] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-2，休眠10s结束
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-3] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-3，休眠10s结束
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-2] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-2，保存开始
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-1] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-1，休眠10s结束
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-3] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-3，保存开始
2021-06-11 16:31:18.921 INFO 27516 --- [ sub-thread-1] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-1，保存开始
2021-06-11 16:31:19.080 DEBUG 27516 --- [ sub-thread-3] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:31:19.080 DEBUG 27516 --- [ sub-thread-1] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:31:19.080 DEBUG 27516 --- [ sub-thread-2] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:31:19.156 DEBUG 27516 --- [ sub-thread-1] com.zhdj.dao.VoteDao.insert : ==> Parameters: 0(String), sub-thread-1(String), 2021-06-11T16:31:19.032(LocalDateTime), 2021-06-11T16:31:19.037(LocalDateTime)
2021-06-11 16:31:19.156 DEBUG 27516 --- [ sub-thread-3] com.zhdj.dao.VoteDao.insert : ==> Parameters: 2(String), sub-thread-3(String), 2021-06-11T16:31:19.032(LocalDateTime), 2021-06-11T16:31:19.037(LocalDateTime)
2021-06-11 16:31:19.156 DEBUG 27516 --- [ sub-thread-2] com.zhdj.dao.VoteDao.insert : ==> Parameters: 1(String), sub-thread-2(String), 2021-06-11T16:31:19.032(LocalDateTime), 2021-06-11T16:31:19.037(LocalDateTime)
2021-06-11 16:31:19.172 DEBUG 27516 --- [ sub-thread-3] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:31:19.178 DEBUG 27516 --- [ sub-thread-2] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:31:19.187 DEBUG 27516 --- [ sub-thread-1] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:31:19.224 INFO 27516 --- [ sub-thread-3] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-3，保存结束
2021-06-11 16:31:19.224 INFO 27516 --- [ sub-thread-1] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-1，保存结束
2021-06-11 16:31:19.224 INFO 27516 --- [ sub-thread-2] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-2，保存结束
2021-06-11 16:31:19.226 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : --------------返回内容----------------
2021-06-11 16:31:19.328 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : Response内容:null
2021-06-11 16:31:19.328 INFO 27516 --- [nio-8080-exec-1] com.zhdj.config.LogAspect : --------------返回内容----------------
2.Future
思路：
1.子线程逻辑返回Future对象
2.主线程逻辑循环判断每个子线程返回的Future对象isDone()是否为true
主线程逻辑
循环判断future.isDone()是否为true
@Override
@Transactional
public void importExcel(File file) {
List<Future> futureList = new ArrayList<>();
for (int i = 0; i < 3; i++) {
VoteDO voteDO = new VoteDO();
voteDO.setTitle(i + "");
Future future = asyncManager.asyncSaveVote(voteDO);
futureList.add(future);
}
//检查所有子线程是否均执行完毕
while (true) {
boolean isAllDone = true;
for (Future future : futureList) {
if (null == future || !future.isDone()) {
isAllDone = false;
}
}
if (isAllDone) {
log.info("所有子线程执行完毕");
break;
}
}
}
子线程逻辑
返回Future对象
@Override
public Future asyncSaveVote(VoteDO voteDO) {
log.info("当前线程为 {}，休眠10s开始", Thread.currentThread().getName());
try {
Thread.sleep(10000L);
} catch (InterruptedException e) {
e.printStackTrace();
}
log.info("当前线程为 {}，休眠10s结束", Thread.currentThread().getName());
log.info("当前线程为 {}，保存开始", Thread.currentThread().getName());
voteDO.setDesc(Thread.currentThread().getName());
voteDao.insert(voteDO);
log.info("当前线程为 {}，保存结束", Thread.currentThread().getName());
//返回需要用AsyncResult类
return new AsyncResult<>(true);
}
日志
2021-06-11 16:42:28.974 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : ===============请求内容===============
2021-06-11 16:42:28.974 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : 请求地址:http://localhost:8080/api/import
2021-06-11 16:42:28.974 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : 请求方式:POST
2021-06-11 16:42:28.975 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : 请求类方法:com.zhdj.controller.ImportController.importExcel
2021-06-11 16:42:28.975 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : 请求类方法参数:[org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile@7e23bacc]
2021-06-11 16:42:28.975 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : ===============请求内容===============
2021-06-11 16:42:28.979 INFO 20492 --- [ sub-thread-5] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-5，休眠10s开始
2021-06-11 16:42:28.979 INFO 20492 --- [ sub-thread-4] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-4，休眠10s开始
2021-06-11 16:42:28.979 INFO 20492 --- [ sub-thread-6] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-6，休眠10s开始
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-6] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-6，休眠10s结束
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-4] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-4，休眠10s结束
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-5] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-5，休眠10s结束
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-6] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-6，保存开始
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-5] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-5，保存开始
2021-06-11 16:42:38.980 INFO 20492 --- [ sub-thread-4] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-4，保存开始
2021-06-11 16:42:38.981 DEBUG 20492 --- [ sub-thread-4] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:42:38.981 DEBUG 20492 --- [ sub-thread-5] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:42:38.981 DEBUG 20492 --- [ sub-thread-6] com.zhdj.dao.VoteDao.insert : ==> Preparing: INSERT INTO vote ( title, `desc`, gmt_create, gmt_modified ) VALUES ( ?, ?, ?, ? )
2021-06-11 16:42:38.982 DEBUG 20492 --- [ sub-thread-5] com.zhdj.dao.VoteDao.insert : ==> Parameters: 1(String), sub-thread-5(String), 2021-06-11T16:42:38.980(LocalDateTime), 2021-06-11T16:42:38.981(LocalDateTime)
2021-06-11 16:42:38.982 DEBUG 20492 --- [ sub-thread-4] com.zhdj.dao.VoteDao.insert : ==> Parameters: 0(String), sub-thread-4(String), 2021-06-11T16:42:38.980(LocalDateTime), 2021-06-11T16:42:38.981(LocalDateTime)
2021-06-11 16:42:38.982 DEBUG 20492 --- [ sub-thread-6] com.zhdj.dao.VoteDao.insert : ==> Parameters: 2(String), sub-thread-6(String), 2021-06-11T16:42:38.980(LocalDateTime), 2021-06-11T16:42:38.981(LocalDateTime)
2021-06-11 16:42:38.988 DEBUG 20492 --- [ sub-thread-5] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:42:38.989 INFO 20492 --- [ sub-thread-5] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-5，保存结束
2021-06-11 16:42:38.993 DEBUG 20492 --- [ sub-thread-6] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:42:38.993 INFO 20492 --- [ sub-thread-6] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-6，保存结束
2021-06-11 16:42:39.004 DEBUG 20492 --- [ sub-thread-4] com.zhdj.dao.VoteDao.insert : <== Updates: 1
2021-06-11 16:42:39.005 INFO 20492 --- [ sub-thread-4] com.zhdj.AsyncManagerImpl : 当前线程为 sub-thread-4，保存结束
2021-06-11 16:42:39.005 INFO 20492 --- [nio-8080-exec-2] com.zhdj.service.impl.VoteServiceImpl : 所有子线程执行完毕
2021-06-11 16:42:39.005 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : --------------返回内容----------------
2021-06-11 16:42:39.005 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : Response内容:null
2021-06-11 16:42:39.005 INFO 20492 --- [nio-8080-exec-2] com.zhdj.config.LogAspect : --------------返回内容----------------
4.多线程共用一个事务
暂时无解决方案，这是弊端
异步调用@Async问题
1.使用背景
在项目中，当访问其他人的接口较慢或者做耗时任务时，不想程序一直卡在耗时任务上，想程序能够并行执行，我们可以使用多线程来并行的处理任务，也可以使用spring提供的异步处理方式@Async。
2.异步处理方式
调用之后，不返回任何数据。
调用之后，返回数据，通过Future来获取返回数据
3.@Async不返回数据
使用@EnableAsync启用异步注解
@Configuration
@EnableAsync
@Slf4j
public class AsyncConfig{
}
在异步处理的方法dealNoReturnTask上添加注解@Async
@Component
@Slf4j
public class AsyncTask {
@Async
public void dealNoReturnTask(){
log.info("Thread {} deal No Return Task start", Thread.currentThread().getName());
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
log.info("Thread {} deal No Return Task end at {}", Thread.currentThread().getName(), System.currentTimeMillis());
}
}
Test测试类：
@SpringBootTest(classes = SpringbootApplication.class)
@RunWith(SpringJUnit4ClassRunner.class)
@Slf4j
public class AsyncTest {
@Autowired
private AsyncTask asyncTask;
@Test
public void testDealNoReturnTask(){
asyncTask.dealNoReturnTask();
try {
log.info("begin to deal other Task!");
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
日志打印结果为：
begin to deal other Task!
AsyncExecutorThread-1 deal No Return Task start
AsyncExecutorThread-1 deal No Return Task end at 1499751227034
从日志中我们可以看出，方法dealNoReturnTask()是异步执行完成的。
dealNoReturnTask()设置sleep 3s是为了模拟耗时任务
testDealNoReturnTask()设置sleep 10s是为了确认异步是否执行完成
4.@Async返回数据
异步调用返回数据，Future表示在未来某个点获取执行结果，返回数据类型可以自定义
@Async
public Future<String> dealHaveReturnTask() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
JSONObject jsonObject = new JSONObject();
jsonObject.put("thread", Thread.currentThread().getName());
jsonObject.put("time", System.currentTimeMillis());
return new AsyncResult<String>(jsonObject.toJSONString());
}
测试类用isCancelled判断异步任务是否取消，isDone判断任务是否执行结束
@Test
public void testDealHaveReturnTask() throws Exception {
Future<String> future = asyncTask.dealHaveReturnTask();
log.info("begin to deal other Task!");
while (true) {
if(future.isCancelled()){
log.info("deal async task is Cancelled");
break;
}
if (future.isDone() ) {
log.info("deal async task is Done");
log.info("return result is " + future.get());
break;
}
log.info("wait async task to end ...");
Thread.sleep(1000);
}
}
日志打印如下，我们可以看出任务一直在等待异步任务执行完毕，用future.get()来获取异步任务的返回结果
begin to deal other Task!
wait async task to end ...
wait async task to end ...
wait async task to end ...
wait async task to end ...
deal async task is Done
return result is {"thread":"AsyncExecutorThread-1","time":1499752617330}
5.异常处理
我们可以实现AsyncConfigurer接口，也可以继承AsyncConfigurerSupport类来实现
在方法getAsyncExecutor()中创建线程池的时候，必须使用 executor.initialize()，
不然在调用时会报线程池未初始化的异常。
如果使用threadPoolTaskExecutor()来定义bean，则不需要初始化
@Configuration
@EnableAsync
@Slf4j
public class AsyncConfig implements AsyncConfigurer {
// @Bean
// public ThreadPoolTaskExecutor threadPoolTaskExecutor(){
// ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
// executor.setCorePoolSize(10);
// executor.setMaxPoolSize(100);
// executor.setQueueCapacity(100);
// return executor;
// }
@Override
public Executor getAsyncExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(10);
executor.setMaxPoolSize(100);
executor.setQueueCapacity(100);
executor.setThreadNamePrefix("AsyncExecutorThread-");
executor.initialize(); //如果不初始化，导致找到不到执行器
return executor;
}
@Override
public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
return new AsyncExceptionHandler();
}
}
异步异常处理类：
@Slf4j
public class AsyncExceptionHandler implements AsyncUncaughtExceptionHandler {
@Override
public void handleUncaughtException(Throwable ex, Method method, Object... params) {
log.info("Async method: {} has uncaught exception,params:{}", method.getName(), JSON.toJSONString(params));
if (ex instanceof AsyncException) {
AsyncException asyncException = (AsyncException) ex;
log.info("asyncException:{}",asyncException.getErrorMessage());
}
log.info("Exception :");
ex.printStackTrace();
}
}
异步处理异常类：
@Data
@AllArgsConstructor
public class AsyncException extends Exception {
private int code;
private String errorMessage;
}
在无返回值的异步调用中，异步处理抛出异常，AsyncExceptionHandler的handleUncaughtException()会捕获指定异常，原有任务还会继续运行，直到结束。
在有返回值的异步调用中，异步处理抛出异常，会直接抛出异常，异步任务结束，原有处理结束执行。
来源：https://blog.csdn.net/qq_39905910/article/details/117819787
0
投稿猜你喜欢
本文实例为大家分享了QT实现用户登录注册的具体代码，供大家参考，具体内容如下#include "widget.h"#in- 前言日常编码过程中，最重要的技能不是说你学会使用很多最新的编程技术或者做出一个高大上的系统。而是你在写代码过程中，对异常的处理，是否系统可以
- 一、用法：list集合中contains() 用于判断集合中 是否 包含指定的元素。list会将括号内的元素和list中存在的元素进行逐个比
- 一、循环语句的几种语法语法：for循环格式：for(初始化语句；条件判断；递进语句){循环体；}while循环格式：初始化语句；while（
- 前言由于刚写项目不久，在写 web 后台接口时，经常会对前端传入的参数进行一些规则校验，如果入参较少还好，一旦需要校验的参数比较多，那么使用
- IntelliJ IDEA是广受Java开发者喜爱的工具，其商业版的价格十分昂贵，如下图：现在有机会免费获取IntelliJ IDEA的正版
- 本文实例讲述了C#基于基姆拉尔森算法计算指定日期是星期几的方法。分享给大家供大家参考。具体分析如下：基姆拉尔森计算公式 W= (d+2*m+
- Android 调用发送短信的方 * 能：调用发送短信功能 1 、 权限 <uses-permission android:name=&
- 1、说明向上转型就是把一个子类引用给一个父类引用，也就是父类引用 引用了子类的对象，即父类 父类对象 = 子类实例。此时通过父类引用变量调用
- 一、引言Good Good Study，Day Day Up，童鞋点个关注，不迷路，么么哒～～～MP自带的条件构造器虽然很强大，有时候也避免
- 简介：任务并行库（Task Parellel Library）是BCL的一个类库，极大的简化了并行编程。使用任务并行库执行循环C#当中我们一
- 背景java程序员一般写的是后端服务是JavaWeb类型的项目，主要包括Http接口和dubbo接口，Http接口一般采用的rest风格，那
- java调用Rsync并发迁移数据并执行校验java代码如下RsyncFile.javaimport lombok.NoArgsConstr
- Tomcat 如何实现WebSocketWebSocket协议属于HTML5标准，越来越多浏览器已经原生支持WebSocket，它能让客户端
- 要讲到C#源码的执行过程 首先要提下程序集，因为Clr并不是和托管摸块打交道的，而是和程序集（dll，exe）1、从哪里来程序集是由一个或者
- ArrayList线程不安全怎么办？有三种解决方法：使用对应的 Vector 类，这个类中的所有方法都加上了 synchronized 关键
- 本文实例讲述了java数据结构与算法之noDups去除重复项算法。分享给大家供大家参考，具体如下：public static void no
- 位运算 位运算的运算分量只能是整型或字符型数据，位运算把运算对象看作是由二进位组成的位串信息，按位完成指
- Springboot 整合 RocketMQ 收发消息创建springboot项目pom.xml添加rocketmq-spring-boot
- macOS搭建Spring Boot开发环境，具体内容如下软硬件环境macOS Sierrajava 1.8.0_65maven 3.5.0
