单线程和多线程处理1W条数据对比代码

package study.interview;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.Random;
import java.util.Set;

public class TestEmailFromList {
final static String[] list = {"qq.com","126.com","168.com","sina.com","baidu.com","soho.com","yeah.net","139.com","hotmail.com"};
public static void main(String[] args) throws InterruptedException {
//email存放容器
LinkedList<Email> emailList = new LinkedList<Email>();
//统计各类邮箱使用人数容器
Map<String, Integer> mapEmail = new HashMap<String, Integer>();
//统计各类邮箱使用人数容器
Map<String, Integer> mapEmailPool = new HashMap<String, Integer>();
Random random=new Random();
//email原始邮箱初始化
for (int i = 0; i < 9999; i++) {
int num = random.nextInt(9);
emailList.add(new Email(String.valueOf(i+"@"+list[num])));
}

// 单线程统计各类邮箱使用人数
long startTime = System.currentTimeMillis();
TestEmailFromList.countingBySingleThread(emailList, mapEmail);
long endTime = System.currentTimeMillis();
System.out.println("单线程统计用时："+(endTime-startTime));

//多线程统计各类邮箱使用人数
long startTime2 = System.currentTimeMillis();
//用多少个线程
TestEmailFromList.countingByMultiThread(emailList, mapEmailPool);
long endTime2 = System.currentTimeMillis();
System.out.println("多线程统计用时："+(endTime2-startTime2));

}
/*
* 单线程统计邮箱使用人数
*/
public static void countingBySingleThread(LinkedList<Email> emailList,Map<String, Integer> mapEmail){
for (int i = 0; i <emailList.size(); i++) {
String key = emailList.get(i).getUserName().split("@")[1];
if(mapEmail.containsKey(key)){
int  value = mapEmail.get(key);
mapEmail.put(key, ++value);
}else{
mapEmail.put(key, 1);
}
}
printMap(mapEmail);
}
/*
* 多线程统计邮箱使用人数
*/
public static  void countingByMultiThread(LinkedList<Email> emailList,Map<String, Integer> mapEmailPool){
ExecutorService executorService = Executors.newCachedThreadPool();
List<Future<Map<String, Integer>>> resultList = new ArrayList<Future<Map<String, Integer>>>();
for (int i = 0; i < 4; i++) {
LinkedList<Email> eList = null;
if(i==3){
eList = new LinkedList<Email>(emailList.subList(i*2500,(i+1)*2500-1));
}else{
eList = new LinkedList<Email>(emailList.subList(i*2500,(i+1)*2500));
}
System.out.println(eList.getFirst().getUserName()+"----"+eList.getLast().getUserName());
//使用ExecutorService执行Callable类型的任务，并将结果保存在future变量中
Future<Map<String, Integer>> future = executorService.submit(new TaskWithResultMap( eList,mapEmailPool));
//将任务执行结果存储到List中
resultList.add(future);

}

//遍历任务的结果
for (Future<Map<String, Integer>> fs : resultList) {
try {
System.out.println(fs.get());
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}finally{
executorService.shutdown();
}
}

printMap(mapEmailPool);
}

/*
* 输出map
*/
public static void printMap(Map<String, Integer> mapEmail){
Set<Entry<String, Integer>> set = mapEmail.entrySet();
for (Entry<String, Integer> entry : set) {
System.out.println("使用"+entry.getKey()+"的人共"+entry.getValue());
}
}

}

class TaskWithResultMap implements Callable<Map<String, Integer>>{
LinkedList<Email> emailList;
Map<String, Integer> mapEmailPool;
public TaskWithResultMap(LinkedList<Email> emailList,Map<String, Integer> mapEmailPool){
this.emailList = emailList;
this.mapEmailPool = mapEmailPool;
}

@Override
public Map<String, Integer> call() throws Exception {
synchronized (mapEmailPool) {
for (int i = 0; i <emailList.size(); i++) {
String key = emailList.get(i).getUserName().split("@")[1];
if(mapEmailPool.containsKey(key)){
int  value = mapEmailPool.get(key);
mapEmailPool.put(key, ++value);
}else{
mapEmailPool.put(key, 1);
}
}
}
return mapEmailPool;
}

}

class MyThread implements Runnable {
LinkedList<Email> emailList;
Map<String, Integer> mapEmailPool;

public MyThread(LinkedList<Email> emailList,Map<String, Integer> mapEmailPool) {
this.emailList = emailList;
this.mapEmailPool = mapEmailPool;
}

public void run() {
while(true){
synchronized (mapEmailPool) {
try {
for (int i = 0; i <emailList.size(); i++) {
String key = emailList.get(i).getUserName().split("@")[1];
if(mapEmailPool.containsKey(key)){
int  value = mapEmailPool.get(key);
mapEmailPool.put(key, ++value);
}else{
mapEmailPool.put(key, 1);
}

}
} catch (Exception e) {
System.out.println(Thread.currentThread().getName()+"异常");
}

}
}
}

}

class Email {
String username;

public Email() {
}

public Email(String username) {
this.username = username;
}

public String getUserName() {
return username;
}
}