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分享JSP使用多线程
想要开多个线程去访问远程的数据接口（因为需要模拟登陆所以返回较慢，一般需要1-5s），同时在页面上实时显示接口返回数据，想问一下这种怎么做才好？(接口返回数据耗时基本是随机的，所以用callable的话需要等那个较慢的；而用runnable的话怎么在run函数中调用jsp的out或response又是个问题）
刚接触jsp还请各位说得详细点，谢谢~
刚接触jsp还请各位说得详细点，谢谢~
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noobfresher 2018-04-28
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贴一下两种方式的实验代码，Runnable的会报IOException
Callable：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.util.concurrent.*" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html"; charset="UTF-8">
<title>Title</title>
</head>
<%!
public class MyCallable implements Callable{
private String url;
private String param;
public MyCallable(String url, String param){
this.url=url;
this.param=param;
}
public String call() throws Exception{
int ran=(int)(Math.random()*5000);
Thread.sleep(ran);
return Thread.currentThread().getName()+", "+this.url+", "+this.param+" sleeped "+ran+" milliseconds!";
}
}
%>
<%
out.println(String.format("%256s",""));
ExecutorService pool = Executors.newFixedThreadPool(5);
Callable[] c=new Callable[5];
Future[] f=new Future[5];
for(int i=0;i<5;i++)
c[i]=new MyCallable("A"+i,"B"+i);
for(int i=0;i<5;i++)
f[i]=pool.submit(c[i]);
for(int i=0;i<5;i++){
out.println(f[i].get().toString()+"</br>");
out.flush();
}
pool.shutdown();
%>
Runnable：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html"; charset="UTF-8">
<title>Title</title>
</head>
<%!
public static void myFunc(String Bits, javax.servlet.jsp.JspWriter myOut){
try{ myOut.println("<div>"+Bits+"</div>"); }
catch(Exception eek) { }
}
public class MyRunnable implements Runnable{
private String url;
private String param;
private javax.servlet.jsp.JspWriter myOut;
public MyRunnable(String url, String param, javax.servlet.jsp.JspWriter myOut){
this.url=url;
this.param=param;
this.myOut=myOut;
}
public void run(){
myFunc(Thread.currentThread().getName()+", "+this.url+", "+this.param, this.myOut);
}
}
%>
<%
for(int i=0;i<5;i++)
new Thread(new MyRunnable("A"+i, "B"+i, out)).start();
%>
