AsyncRestTemplate 异步服务访问

需要先配置SpringMVC支持异步访问，需要Servlet 3.0支持，导入3.0包

            javax.servlet
            javax.servlet-api
            3.0.1
            provided
       
       
            javax.servlet.jsp
            jsp-api
            2.2
            provided
       

web.xml 也需要用3.0的配置，一下不支持 true

  Archetype Created Web Application
  
		contextConfigLocation
		classpath:spring/spring.xml
	
	
		org.springframework.web.context.ContextLoaderListener
	
	
	
		springmvc
		org.springframework.web.servlet.DispatcherServlet
		
			contextConfigLocation
			classpath:spring/spring-mvc1.xml
		
		1
		true
	
	
		springmvc
		/
	

spring配置

Controller 

package com.smart.web;

import java.util.concurrent.Callable;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.smart.domain.User;

@RestController
@RequestMapping("/sp1")
public class Sp1Controller {
	@RequestMapping("/m1")
	public String m1(){
		return "1";
	}
	@RequestMapping("/m2")
	public Callable m2(){
		System.out.println("abc");
		return new Callable() {
			@Override
			public User call() throws Exception {
				Thread.sleep(10L*1000);
				User user = new User();
				user.setUserId("1");
				user.setUserName("tom");
				return user;
			}
			
		};
	}
}

m2方法，模拟延时10秒

测试：

package com.smart.test;

import org.junit.Test;
import org.springframework.http.ResponseEntity;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;
import org.springframework.web.client.AsyncRestTemplate;

import com.smart.domain.User;

public class Sp1Test {
	
	@Test
	public void m2Test() throws InterruptedException{
		AsyncRestTemplate template = new AsyncRestTemplate();
		
		ListenableFuture> future = template.getForEntity("http://localhost:8086/s3/sp1/m2", User.class);
		
		future.addCallback(new ListenableFutureCallback>() {

			@Override
			public void onSuccess(ResponseEntity arg0) {
				System.out.println("### handler OK"+arg0.getBody());
				
			}

			@Override
			public void onFailure(Throwable arg0) {
				System.out.println("### handler error"+arg0);
				
			}
		});
		System.out.println("=========no wait");
		Thread.sleep(20L*1000); //为了防止测试提前结束，关闭程序
		
	}
	
}

使用junit测试，为防止主程序结束而结束整个执行，需要加入延时20秒

日志：

客户端：

[DEBUG] [2017-11-23 15:43:08,290] [org.springframework.web.client.AsyncRestTemplate main] - Created asynchronous GET request for "http://localhost:8086/s3/sp1/m2"
[DEBUG] [2017-11-23 15:43:08,383] [org.springframework.web.client.RestTemplate main] - Setting request Accept header to [application/json, application/*+json]
=========no wait
[DEBUG] [2017-11-23 15:43:18,411] [org.springframework.web.client.AsyncRestTemplate SimpleAsyncTaskExecutor-1] - Async GET request for "http://localhost:8086/s3/sp1/m2" resulted in 200 (OK)
[DEBUG] [2017-11-23 15:43:18,413] [org.springframework.web.client.RestTemplate SimpleAsyncTaskExecutor-1] - Reading [class com.smart.domain.User] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@66720ae]
### handler OKcom.smart.domain.User@321bc965

服务端

abc
[DEBUG] [2017-11-23 15:43:08,409] [org.springframework.web.context.request.async.WebAsyncManager http-bio-8080-exec-3] - Concurrent handling starting for GET [/s3/sp1/m2]
[DEBUG] [2017-11-23 15:43:08,409] [org.springframework.web.servlet.DispatcherServlet http-bio-8080-exec-3] - Leaving response open for concurrent processing
[DEBUG] [2017-11-23 15:43:18,406] [org.springframework.web.context.request.async.WebAsyncManager MvcAsync2] - Concurrent result value [com.smart.domain.User@646ce1c3] - dispatching request to resume processing
[DEBUG] [2017-11-23 15:43:18,406] [org.springframework.web.servlet.DispatcherServlet http-bio-8080-exec-4] - DispatcherServlet with name 'springmvc' resumed processing GET request for [/s3/sp1/m2]
[DEBUG] [2017-11-23 15:43:18,407] [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping http-bio-8080-exec-4] - Looking up handler method for path /sp1/m2
[DEBUG] [2017-11-23 15:43:18,407] [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping http-bio-8080-exec-4] - Returning handler method [public java.util.concurrent.Callable com.smart.web.Sp1Controller.m2()]
[DEBUG] [2017-11-23 15:43:18,407] [org.springframework.beans.factory.support.DefaultListableBeanFactory http-bio-8080-exec-4] - Returning cached instance of singleton bean 'sp1Controller'
[DEBUG] [2017-11-23 15:43:18,407] [org.springframework.web.servlet.DispatcherServlet http-bio-8080-exec-4] - Last-Modified value for [/s3/sp1/m2] is: -1
[DEBUG] [2017-11-23 15:43:18,407] [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter http-bio-8080-exec-4] - Found concurrent result value [com.smart.domain.User@646ce1c3]
[DEBUG] [2017-11-23 15:43:18,408] [org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor http-bio-8080-exec-4] - Written [com.smart.domain.User@646ce1c3] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@2eab8f37]
[DEBUG] [2017-11-23 15:43:18,409] [org.springframework.web.servlet.DispatcherServlet http-bio-8080-exec-4] - Null ModelAndView returned to DispatcherServlet with name 'springmvc': assuming HandlerAdapter completed request handling
[DEBUG] [2017-11-23 15:43:18,409] [org.springframework.web.servlet.DispatcherServlet http-bio-8080-exec-4] - Successfully completed request