使用多线程提高REST服务器性能

异步处理REST服务

1、使用Runnable异步处理Rest服务

释放主线程，启用副线程进行处理，副线程处理完成后直接返回请求

主要代码

import java.util.concurrent.Callable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 *
 * @author hzc
 *
 */
@RestController
public class AsyncController {

    private Logger logger = LoggerFactory.getLogger(AsyncController.class);

    @RequestMapping("/order")
    public Callable<String> order() throws InterruptedException {
        logger.info("主线程开始");

        Callable<String> result = new Callable<String>() {

            @Override
            public String call() throws Exception {
                logger.info("副线程开始");
                Thread.sleep(1000);
                logger.info("副线程结束");
                return "success";
            }

        };
        logger.info("主线程返回");
        return result;

    }
}

2、使用DeferredResult异步处理Rest服务

释放主线程，启用副线程1进行前处理，副线程2进行后处理，副线程2处理完后返回请求

模拟业务场景

主线程调用副线程1进行业务处理，将任务放于消息队列，副线程2监听消息队列，并处理队列的任务，在使用DeferredResult获取队列返回的结果，返回给前端

Controller类

package com.maple.security.web.async;

import org.apache.commons.lang.RandomStringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.async.DeferredResult;

/**
 *
 * @author hzc
 *
 */
@RestController
public class AsyncController {

    private Logger logger = LoggerFactory.getLogger(AsyncController.class);

    @Autowired
    private MockQueue mockQueue;

    @Autowired
    private DeferredResultHolder deferredResultHolder;

    @RequestMapping("/order")
    public DeferredResult<String> order() throws InterruptedException {
        logger.info("主线程开始");

        String orderNumber = RandomStringUtils.randomNumeric(8);
        mockQueue.setPlaceOrder(orderNumber);

        DeferredResult<String> result = new DeferredResult<>();
        deferredResultHolder.getMap().put(orderNumber, result);
        logger.info("主线程返回");
        return result;

    }
}

模拟消息队列类

package com.maple.security.web.async;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 *
 * @author hzc
 *
 */
@Component
public class MockQueue {

    private Logger logger = LoggerFactory.getLogger(MockQueue.class);

    // 生成下单
    private String placeOrder;

    // 完成下单
    private String completeOrder;

    public String getPlaceOrder() {
        return placeOrder;
    }

    public void setPlaceOrder(String placeOrder) {
        new Thread(() -> {
            logger.info("接到下单请求");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            this.completeOrder = placeOrder;
            logger.info("下单请求处理完毕," + placeOrder);
        }).start();

    }

    public String getCompleteOrder() {
        return completeOrder;
    }

    public void setCompleteOrder(String completeOrder) {
        this.completeOrder = completeOrder;
    }
}

监听消息队列并处理类

package com.maple.security.web.async;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;

@Component
public class QueueListener implements ApplicationListener<ContextRefreshedEvent> {

    private Logger logger = LoggerFactory.getLogger(QueueListener.class);

    @Autowired
    private MockQueue mockQueue;

    @Autowired
    private DeferredResultHolder deferredResultHolder;

    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {

        new Thread(() -> {
            while (true) {
                if (StringUtils.isNotBlank(mockQueue.getCompleteOrder())) {
                    String orderNumber = mockQueue.getCompleteOrder();
                    logger.info("返回订单处理结果：" + orderNumber);
                    deferredResultHolder.getMap().get(orderNumber).setResult("place order success");

                    mockQueue.setCompleteOrder(null);

                } else {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();

    }
}

异步处理结果类

/**
 *
 */
package com.maple.security.web.async;

import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Component;
import org.springframework.web.context.request.async.DeferredResult;

/**
 * @author hzc
 *
 */
@Component
public class DeferredResultHolder {

    private Map<String, DeferredResult<String>> map = new HashMap<String, DeferredResult<String>>();

    public Map<String, DeferredResult<String>> getMap() {
        return map;
    }

    public void setMap(Map<String, DeferredResult<String>> map) {
        this.map = map;
    }

}

3、异步处理配置

原文地址：https://www.cnblogs.com/maple92/p/11616472.html