bufferedWriter和PrintWriter

[波哥Polly]

我在做TCP通信的练习时用到了bufferedWriter和printWriter两个类，但出现了一个问题：用printWriter写出时，Server那边能收到信息，但BufferedWriter写出时，服务器收不到，　为什么？　代码如下：

下面的失败，但是换成注释的代码又可以；请高手指点！！

//Client端；
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.PrintWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;

public class ChatClient {
public static void main(String[] args) {

BufferedWriter bw = null;
//PrintWriter pw = null;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

try {
Socket s = new Socket("127.0.0.1",6006);
bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
//pw = new PrintWriter(s.getOutputStream());
String msg = br.readLine();
while(msg != null && msg.trim().length() != 0) {
bw.write(msg);
//pw.println(msg);
bw.flush();
msg = br.readLine();
}
bw.close();
br.close();
}catch(Exception e) {
System.out.println("与服务器断开!");
}
}
}


//Server端；

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

class ChatServer {
public static void main(String[] args)
{
ServerSocket ss = null;

try {
ss = new ServerSocket(6006);
while(true) {
Socket s = ss.accept();
new ChatConn(s);
}

} catch (Exception e) {
System.out.println("error!");
e.printStackTrace();
}
}

static class ChatConn implements Runnable {
Socket s = null;
BufferedReader br = null;
public ChatConn(Socket s) {
this.s = s;
new Thread(this).start();
}
public void run() {
try{
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
String msg = br.readLine();
while(msg != null && msg.trim().length() != 0) {
System.out.println(msg);
msg = br.readLine();
}

} catch(Exception e) {
System.out.println("断开通信！");
}
}
}
}

[Emiya_wang]

bufferedWriter需要flush 保证缓冲区中的数据都写入

[波哥Polly]

我写了flush();但还是有错，server端接不到数据

[humcomm]

不了解，帮定

[一洽客服系统]

改一下客户端的代码试试

import java.io.BufferedReader; 
import java.io.BufferedWriter; 
import java.io.InputStreamReader; 
import java.io.OutputStreamWriter; 
import java.net.Socket; 

public class ChatClient { 
public static void main(String[] args) { 

BufferedWriter bw = null; 
//PrintWriter pw = null; 
BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 

try { 
Socket s = new Socket("127.0.0.1",6006); 
bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream())); 
//pw = new PrintWriter(s.getOutputStream()); 
String msg = br.readLine(); 
while(msg != null && !msg.trim().equals("bye")) { 
bw.write(msg); 
//pw.println(msg); 

System.out.println(">>>>>>>>>."+msg);
bw.newLine();
msg = br.readLine(); 
} 
bw.flush(); 
bw.close(); 
br.close(); 
}catch(Exception e) { 
System.out.println("与服务器断开!"); 
} 
} 
} 

[波哥Polly]

还是收不到

[lz12366007]

关注中....

[ericax]

[Quote=引用 7 楼 taolei 的回复:]
因为比PrintWriter.println少了换行符，客户端永远收不到一行结束的标志。
在flush前加BufferedWriter.newLine就可以了。
[/Quote]
顶！！

[taolei]

因为比PrintWriter.println少了换行符，客户端永远收不到一行结束的标志。
在flush前加BufferedWriter.newLine就可以了。

[小樊]

PrintWriter方法可以写不同平台的换行符，bufferedwriter.newLine换行，使用PrintWriter比较好！