求助！希望大家能指点下！万分感谢！

[wrw123]

//我是初学者请大家多多指点！
//客户端：
import java.io.*;
import java.net.*;
public class Client
{
public static void main(String args[])
{
try
{
Socket socket=new Socket("localhost",8888);
BufferedReader br1=new BufferedReader(new InputStreamReader(System.in));
PrintWriter pw=new PrintWriter(socket.getOutputStream());
BufferedReader br2=new BufferedReader(new InputStreamReader(socket.getInputStream()));

String readline;
readline=br1.readLine();
while (!readline.equals("bye"))
{
pw.print(readline);
pw.flush();
System.out.println("Client:"+readline);
System.out.println("Server:"+br2.readLine());
readline=br1.readLine();
}
pw.close();
br2.close();
socket.close();
}catch(Exception e)
{
System.out.println("Error:"+e);
}
}
}

//服务器端：
import java.net.*;
import java.io.*;
import java.applet.Applet;
public class Server {
public static void main(String[] args) {
try
{
ServerSocket server=null;
try{
server=new ServerSocket(8888);
}catch(Exception e){
System.out.println("error:::"+e.toString());
}

Socket socket=null;
try{
socket=server.accept();
}catch(Exception e){
System.out.println("Error"+e);
}

String line;
BufferedReader br1=new BufferedReader(new InputStreamReader(System.in));
BufferedReader br2=new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter pw=new PrintWriter(socket.getOutputStream());
System.out.println("Client:"+br2.readLine());
line=br1.readLine();
while(!line.equals("bye")){
pw.println(line);
pw.flush();
System.out.println("Server:"+line);
System.out.println("Client:"+br2.readLine());
line=br1.readLine();
}
pw.close();
br1.close();
socket.close();
server.close();
}catch(Exception e)
{
System.out.println("Server Error:"+e);
}
}
}

运行后服务器端出现错误：
Can not listenjava.net.BindException: Address already in use: JVM_Bind
Errorjava.lang.NullPointerException
Server Error:java.lang.NullPointerException

[pigrain]

我运行后没有错误，但你的程序有些问题，我想实现不了什么功能

[pigrain]

我稍微修改了一下，希望对你有点帮助，呵呵
import java.net.*;
import java.io.*;

public class Server {

public static void main(String[] args) throws IOException{


ServerSocket server=new ServerSocket(8888);
try{
Socket socket=server.accept();
try{


String line;
PrintWriter br1=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);

BufferedReader br2=new BufferedReader(new InputStreamReader(socket.getInputStream()));


while(true){

line=br2.readLine();
if(line.equals("BYE")) break;

System.out.println("From Client:"+line);
br1.println("From Server:"+line);
}
}


finally{

socket.close();
}
}
finally{}
}
}
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import java.io.*;
import java.net.*;
public class Client
{
private static PrintWriter out;
public static void main(String args[])
throws IOException{

try{

Socket socket=new Socket("localhost",8888);
try{

BufferedReader br1=new BufferedReader(new InputStreamReader(System.in));
PrintWriter out = new PrintWriter(socket.getOutputStream(),true);
BufferedReader br2=new BufferedReader(new InputStreamReader(socket.getInputStream()));
while(true){

String readline=br1.readLine();

System.out.println("Client(YOUR INPUT):"+readline);
out.println(readline);
String str=br2.readLine();
System.out.println(str);
if(readline.equals("BYE")) break;

}



}
finally
{
socket.close();
}
}
finally{
}
}
}
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
注：我比较喜欢try{} finally{}，所以。。呵

[flashactionscript]

端口地址被占用！

[wrw123]

我换了端口也没用！