1.DeferredResult

Spring supports HTTP asynchronous return

2. Asynchronous processing

Start a new thread, process the data and return the value.

3. Code examples

1）controller

package com.liuxd.controller;

import com.liuxd.entity.Responses;
import com.liuxd.service.TaskService2;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.async.DeferredResult;

@Slf4j
@RestController
public class AsyncCtr2 {

    @Autowired
    private TaskService2 taskService2;

    @GetMapping(value = "/getResult")
    public DeferredResult<Responses<String>> getResult() {
        log.info("HTTP request received...");
        long startTime = System.currentTimeMillis();

        DeferredResult<Responses<String>> deferredResult = new DeferredResult<Responses<String>>();

        new Thread(new Runnable() {
            @Override
            public void run() {
                taskService2.getData(deferredResult);
            }
        }).start();

        log.info("The task of the receiving HTTP request thread has been completed, exit!");
        long endTime = System.currentTimeMillis();
        log.info("http Total request time. " + (endTime - startTime) + "ms");

        return deferredResult;

    }
}

2）service

package com.liuxd.service;

import com.liuxd.entity.Responses;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.web.context.request.async.DeferredResult;

@Slf4j
@Service
public class TaskService2 {

    public void getData(DeferredResult<Responses<String>> deferredResult) {

        log.info("Call service asynchronous with return method, start execution...");
        long startTime = System.currentTimeMillis();

        try {
            Thread.sleep(2500L);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        log.info("Call service asynchronous has return method, the end of execution!!!") ;

        long endTime = System.currentTimeMillis();
        log.info("Total time taken to call service asynchronous return method. " + (endTime - startTime) + "ms");

        deferredResult.setResult(new Responses<>(0, "Done", "SUCCESS"));

    }


}

3）Responses

package com.liuxd.entity;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class Responses<T> {

    private Integer code;

    private String msg;

    private T data;

}

4) Print results

5) Result analysis

1) The HTTP main thread accepts the request and ends after processing the request

2) After the asynchronous thread ends, returns the