java多线程学习笔记_JAVA_编程开发_程序员俱乐部

问题情境：数据存储在搜索服务器，现需测试搜索提供查询更新接口性能,用户提交更新后立即查询，测试搜索接口实时性
模拟多个用户同时查询提交多条数据，要求用户数、批量提交数、查询和提交时间间隔都为可配

class="java" name="code">
package com.ifeng.sisp.util;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import com.ifeng.sisp.pojo.Article;
import com.ifeng.sisp.service.ArticleService;
import com.ifeng.sisp.service.impl.ArticleServiceImpl;

public class TestTreads {
	public static List<String> spend = new ArrayList<String>();//用于存储耗时
	static String num = null;
	static String batch = null;
	static String millis = null;
	public static void add(long spendTime){
		String time = spendTime + "";
		spend.add(time);
	}
	public static void main(String[] args) throws Exception,ParseException{
		args = new String[]{"-num","30","-batch","57","-millis","500"};
		for(int i=0;i<args.length;i++){
			if(args[i].equals("-num")){
				i++;
				num=args[i];
			}else if(args[i].equals("-batch")){
				i++ ;
				batch=args[i];
			}else if(args[i].equals("-millis")){
				i++;
				millis=args[i];
			}else{
				System.err.print("no such parameter");
				System.exit(0);
			}
		}
		if(num==null){
			System.err.print("num can not be null !");
			System.exit(0);
		}
		if(batch==null){
			System.err.print("batch can not be null !");
			System.exit(0);
		}
		if(millis==null){
			System.err.print("millis can not be null !");
			System.exit(0);
		}
		
		int threadNum = Integer.parseInt(num);
		CountDownLatch threadSignal = new CountDownLatch(threadNum);
		int bt = Integer.parseInt(batch);
		long mis = Long.parseLong(millis);
		for(int i=0;i<threadNum;i++){
			submitThread st = new submitThread(i,bt,threadSignal,mis);
			Thread thread = new Thread(st);
			thread.start();
		}
		System.out.println("all submit start");
		threadSignal.await();
		System.out.println("all thread over");
		StringBuffer sb = new StringBuffer();
		Collections.sort(spend);
		for(String s : spend){
			sb.append(s).append("\n");
		}
		FileUtil.write("E:/spendTime.txt", sb.toString());
	}

}
class submitThread implements Runnable{
	private int num;
	private int batch;
	private long millis;
	private CountDownLatch threadSignal;
	ArticleService service = new ArticleServiceImpl();
	public submitThread(int num,int batch,CountDownLatch threadSignal,long millis){
		this.batch = batch;
		this.num = num;
		this.threadSignal = threadSignal;
		this.millis = millis;
	}
	public void run(){
		String dataServer = "http://ip:port/solr/comment";
		for(int i =0;i<1;i++){
			System.out.println(Thread.currentThread()+" is run " + i);
			//获取文章。进行审核
			String source = "http://ip:port/solr/comment/select?q=";
			source += "channel:ifeng_comment*" + "+time:[2014-06-20T00:00:00Z+2014-06-20T23:11:20Z]";
			source += "&wt=xml" + "&start=" + num*batch + "&rows=" + batch;
			try{
			source += "&sort=" + URLEncoder.encode("time desc", "utf-8");
			}catch(UnsupportedEncodingException e){
				e.printStackTrace();
			}
			List<Article> as = new ArrayList<Article>();
			as = MsgConvertUtil.parseArticleXml(source);
			List<Article> operate = new ArrayList<Article>();
			for(Article a : as){
				a.setManualStatus("1");
				a.setStatus("2");
				operate.add(a);
			}
			/*if(i%2==0){
				for(Article a : as){
					a.setManualStatus("2");
					a.setStatus("3");
					operate.add(a);
				}
			}else{
				for(Article a : as){
					a.setManualStatus("1");
					a.setStatus("2");
					operate.add(a);
				}
			}*/
			
			
			String msg = MsgConvertUtil.createArticleXmlTest(operate);
			String url = dataServer + "/update?softCommit=true";
			// System.out.println(msg);
			long start = System.currentTimeMillis();
			String res = MsgUtil.sendPostMsg(url, msg, "struts");
			long end = System.currentTimeMillis();
			System.out.println(res);
			int count = 0;
			try{
				Thread.sleep(millis);
				}catch(InterruptedException e){
					e.printStackTrace();
				}
			
			List<Article> fas = MsgConvertUtil.parseArticleXml(source);
			for(Article a : fas){
				if(!a.getStatus().equals("2")){
					count++;
					System.out.println(a.getId()+"未及时"+a.getStatus());
				}
			}
			/*if(i%2==0){
				for(Article a : fas){
					if(!a.getStatus().equals("3")){
						count++;
						System.out.println(a.getId()+"未及时"+a.getStatus());
					}
				}
			}else{
				for(Article a : fas){
					if(!a.getStatus().equals("2")){
						count++;
						System.out.println(a.getId()+"未及时"+a.getStatus());
					}
				}
			}*/
			
			/*for(Article a : operate){
				long s = System.currentTimeMillis();
				Article article = service.selectById(a.getId(), dataServer, "audit");
				System.out.println(System.currentTimeMillis()-s);
				if(!article.getStatus().equals("3"))
					System.out.println(article.getId()+"未及时"+article.getStatus());
			}*/
			long spend = end - start;
			
			if(count!=0)
				TestTreads.add(spend);
			
			try{
				Thread.sleep(2000);
				}catch(InterruptedException e){
					e.printStackTrace();
				}
			
		}
		threadSignal.countDown();
	}
}

解析：CountDownLatch类
CountDownLatch类是一个同步计数器，构造是传入int初始值，每调用一次countDown()方法，计数器减1；调用await()方法会一直阻塞当前线程，直到计数器为0
CountDownLatch的应用场景：有一个任务想要往下执行，但必须等到其他任务执行完成，这里我是在多个线程执行完更新查询结束后，想要记录所有耗时写入文件