springboot之同步與異步

1異步與同步

以一個例子解釋：李明拿100w去買房子，

同步的步驟是1李明用手機支付100w給銷售部的負責人jimao,2jimao收到錢，然后3把房子的鑰匙給李明

異步的步驟是上面的123步驟同一時間進行

2異步代碼

2.1 創建一個空的springboot項目

可以參考 [ 超鏈接 ]+ ( https://www.cnblogs.com/zhushilai/p/14006484.html ) 中的創建方式

<a href="https://www.cnblogs.com/zhushilai/p/14006484.html" target="_blank">超鏈接</a>

 

2.2 pom.xml添加依賴包

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.3.3.RELEASE</version>
  <relativePath/> <!-- lookup parent from repository -->
 </parent>
 <groupId>com.example</groupId>
 <artifactId>spring_task</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <name>spring_task</name>
 <description>Demo project for Spring Boot</description>
​
 <properties>
  <java.version>1.8</java.version>
  <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
 </properties>
 <dependencies>
  <!-- web依賴的jar  -->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
 
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter</artifactId>
  </dependency>
​
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
  </dependency>
 </dependencies>
​
 <build>
  <plugins>
   <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
   </plugin>
  </plugins>
 </build>
​
</project>
​

2.3創建異步類AsyncTest

package com.example.spring_task.async;
​
import java.util.concurrent.Future;
​
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Component;
​
/**
 * 異步任務業務類
 * @author Administrator
 * @Async 異步注解，可以標記在類上面，作用於類中的所有方法，也可以標記在方法上面
 */
@Component
@Async
public class AsyncTest {
 
 public void task1() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(1000L);
  long end =System.currentTimeMillis();
  System.out.println("任務1耗時："+(end-begin));
 }
 
 public void task2() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(2000L);
  long end =System.currentTimeMillis();
  System.out.println("任務2耗時："+(end-begin));
 }
 
 public void task3() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(3000L);
  long end =System.currentTimeMillis();
  System.out.println("任務3耗時："+(end-begin));
 }
 //獲取異步結果
 public Future<String> task4() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(3000L);
  long end =System.currentTimeMillis();
  System.out.println("任務4耗時："+(end-begin));
  return new AsyncResult<String>("任務4");
 }
 
 public Future<String> task5() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(2000L);
  long end =System.currentTimeMillis();
  System.out.println("任務5耗時："+(end-begin));
  return new AsyncResult<String>("任務5");
 }
 
 public Future<String> task6() throws InterruptedException {
  long begin=System.currentTimeMillis();
  Thread.sleep(1000L);
  long end =System.currentTimeMillis();
  System.out.println("任務6耗時："+(end-begin));
  return new AsyncResult<String>("任務6");
 }
 
}
​

2.4 添加Controller

AsyncController

package com.example.spring_task.controller;
​
​
import java.util.concurrent.Future;
​
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
​
import com.example.spring_task.async.AsyncTest;
import com.example.spring_task.utils.JsonData;
​
@RestController
@RequestMapping("/api/v1")
public class AsyncController {
​
 /**
 * 將異步類注解進來
 */
 @Autowired
 private AsyncTest asyncTest;
 
 @GetMapping("asyncTest")
 public JsonData exetask() throws InterruptedException {
  long begin=System.currentTimeMillis();
//  asyncTest.task1();
//  asyncTest.task2();
//  asyncTest.task3();
  Future<String> task4=asyncTest.task4();
  Future<String> task5=asyncTest.task5();
  Future<String> task6=asyncTest.task6();
  for (;;) {
   if(task4.isDone()&&task5.isDone()&&task6.isDone()) {
    break;
   }
  }
  
  long end=System.currentTimeMillis();
  long total=end-begin;
  System.out.println("執行總耗時"+total);
  return JsonData.buildSuccess(total);
 }
}
​

2.5添加工具類JsonData

JsonData

package com.example.spring_task.utils;
​
import java.io.Serializable;
​
public class JsonData implements Serializable{
 private static final long serialVersionUID = 1L;
 /**
 * 狀態碼
 * 0表示成功;1表示處理中;-1表示失敗
 */
 private Integer code;
 /**
 * 數據
 */
 private Object data;
 /**
 * 描述
 */
 private String msg;
 public JsonData(Integer code, Object data, String msg) {
  super();
  this.code = code;
  this.data = data;
  this.msg = msg;
 }
 /**
 * 成功，傳入數據
 * @return
 */
 public static JsonData buildSuccess() {
  return new JsonData(0,null,null);
 }
 
 /**
 * 成功，傳入數據
 * @return
 */
 public static JsonData buildSuccess(Object data) {
  return new JsonData(0,data,null);
 }
 /**
 * 成功，傳入數據和狀態碼
 * @param data
 * @param code
 * @return
 */
 public static JsonData buildSuccess(Object data,Integer code) {
  return new JsonData(code,data,null);
 }
 /**
 * 成功，傳入狀態碼和信息
 * @param msg
 * @param code
 * @return
 */
 public static JsonData buildSuccess(String msg,Integer code) {
  return new JsonData(code,msg,null);
 }
 
 
 /**
 * 失敗，傳入描述信息
 * @return
 */
 public static JsonData buildError(String msg) {
  return new JsonData(-1,null,msg);
 }
 
 /**
 * 失敗，傳入信息和狀態碼
 * @param msg
 * @param code
 * @return
 */
 public static JsonData buildError(String msg,Integer code) {
  return new JsonData(code,null,msg);
 }
 /**
 * 失敗，出入數據和狀態碼
 * @param data
 * @param code
 * @return
 */
 public static JsonData buildError(Object data,Integer code) {
  return new JsonData(code,data,null);
 }
 
 public JsonData() {}
 
 
 public Integer getCode() {
  return code;
 }
 public void setCode(Integer code) {
  this.code = code;
 }
 public Object getData() {
  return data;
 }
 public void setData(Object data) {
  this.data = data;
 }
 public String getMsg() {
  return msg;
 }
 public void setMsg(String msg) {
  this.msg = msg;
 }
 @Override
 public String toString() {
  return "JsonData [code=" + code + ", data=" + data + ", msg=" + msg + "]";
 }
}
​

2.6 給application添加注解

package com.example.spring_task;
​
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
/**
 * 
 * @author Administrator
 * @SpringBootApplication 掃描所有類
 * @EnableScheduling 開啟定時任務
 * @EnableAsync 開啟異步類
 */
@SpringBootApplication
@EnableScheduling
@EnableAsync
public class SpringTaskApplication {
​
 public static void main(String[] args) {
  SpringApplication.run(SpringTaskApplication.class, args);
 }
​
}
​

2.7執行接口接口

接口地址：localhost:8080/api/v1/asyncTest

接口結果：

任務6耗時：1000
任務5耗時：2000
任務4耗時：3000
執行總耗時3104

3同步代碼

和上面的異步代碼一樣，只需要將異步類中的注解@Async注釋掉

接口地址：localhost:8080/api/v1/asyncTest

接口結果：

任務4耗時：3000
任務5耗時：2001
任務6耗時：1000
執行總耗時6004