Java中的代理服务器：无法将响应发送回客户端
我正在尝试编写一段代码来实现代理服务器。但是，我无法将数据发送回客户端，因为响应如下所示Java中的代理服务器：无法将响应发送回客户端,java,sockets,proxy,Java,Sockets,Proxy,我正在尝试编写一段代码来实现代理服务器。但是，我无法将数据发送回客户端，因为响应如下所示 package ownproxy; /** * * @author mklrjv */ import java.net.*; import java.io.*; import java.nio.CharBuffer; import java.util.logging.Level; import java.util.logging.Logger; public class InterceptionP
package ownproxy;
/**
*
* @author mklrjv
*/
import java.net.*;
import java.io.*;
import java.nio.CharBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class InterceptionProxy2 {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
boolean listening = true;
int port = 1234;
try {
serverSocket = new ServerSocket(port);
} catch (IOException e) {
System.out.println("Port Error");
System.exit(-1);
}
while (listening) {
new ProxyThread2(serverSocket.accept()).start();
}
serverSocket.close();
}
}
class ProxyThread2 extends Thread {
private Socket socket = null;
private static final int BUFFER_SIZE = 32768;
public ProxyThread2(Socket socket) {
super("ProxyThread2");
this.socket = socket;
}
public void run() {
PrintWriter outGoing = null;
try {
outGoing = new PrintWriter(socket.getOutputStream(), true);
BufferedReader inComing = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String incomingRequest;
String url = "";
String request = "";
String response = "";
//Take the incoming request
char[] buf = new char[1000000];
inComing.read(buf);
request = new String(buf);
//Create a new socket for connecting to destination server
Socket connSocket = new Socket("localhost", 80);
PrintWriter pOut = new PrintWriter(connSocket.getOutputStream(), true);
BufferedReader pIn = new BufferedReader(new InputStreamReader(connSocket.getInputStream()));
//Put data into the new socket(to the apache server) and receive its output
pOut.print(request);
pIn.read(buf);
response = new String(buf);
System.out.println(response);
//Put data back into the original client socket
outGoing.write(response);
} catch (IOException ex) {
Logger.getLogger(ProxyThread2.class.getName()).log(Level.SEVERE, null, ex);
} finally {
outGoing.close();
}
}
}
HTTP/1.1 414 Request-URI Too Large
Date: Sun, 01 Sep 2013 14:52:20 GMT
Server: Apache/2.2.22 (Ubuntu)
Vary: Accept-Encoding
Content-Length: 325
Connection: close
Content-Type: text/html; charset=iso-8859-1
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>414 Request-URI Too Large</title>
</head><body>
<h1>Request-URI Too Large</h1>
<p>The requested URL's length exceeds the capacity
limit for this server.<br />
</p>
<hr>
<address>Apache/2.2.22 (Ubuntu) Server at 127.0.1.1 Port 80</address>
</body></html>
414错误的原因并不明显。如果您在代理上未使用web浏览器，而是手动发送GET请求或其他非http请求，则代码中的错误（请参见下文）可能会导致GET请求中包含8196个以上的字符，这是Apache的默认限制 您应该更改代码，使其使用Stringbuffer、offset、length构造函数创建字符串，该构造函数使用读取的字节量，而不是完整的缓冲区，如果请求和响应很短，该缓冲区可能包含许多空值。此外，您应该考虑将输出刷新到代理客户端。这是您的代码和这些更改
public void run() {
PrintWriter outGoing = null;
try {
outGoing = new PrintWriter(socket.getOutputStream(), true);
BufferedReader inComing = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String incomingRequest;
String url = "";
String request = "";
String response = "";
//Take the incoming request
char[] buf = new char[100000];
int bytesRead = inComing.read(buf);
request = new String(buf, 0, bytesRead);
//Create a new socket for connecting to destination server
Socket connSocket = new Socket("localhost", 10003);
PrintWriter pOut = new PrintWriter(connSocket.getOutputStream(), true);
//Reader for response from destination server
BufferedReader pIn = new BufferedReader(new InputStreamReader(connSocket.getInputStream()));
//Put data into the new socket(to the apache server) and receive its output
pOut.print(request);
pOut.flush();
bytesRead = pIn.read(buf);
if(bytesRead > 0) {
response = new String(buf, 0, bytesRead);
}
System.out.println(response);
//Put data back into the original client socket
outGoing.write(response);
} catch (IOException ex) {
Logger.getLogger(ProxyThread2.class.getName()).log(Level.SEVERE, null, ex);
} finally {
outGoing.close();
}
不能像这样编写HTTP代理。您需要两个线程，每个方向一个，都只是复制字节。原因是HTTP保持活动状态。你不知道请求者的最终响应在哪里，因为它解析头、块等，而且这一切都太难了