一个java难题

Question

下面代码有没错，高手给看看。编写一个客户/服务器程序qmj，服务器端的功能是计算圆的面积。客户端将圆的半径发送给服务器端，服务器端计算得出的圆面积将发送给客户端，并在客户端显示。qmjClient：import java.io.*;
import java.net.*;public class qmjClient
{
   public static void main(String[] args)
   {
      try
  {
 Socket socket=new Socket("127.0.0.1",4700);
         
         PrintWriter os=new PrintWriter(socket.getOutputStream());
         BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));         BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));         String readline;
         readline=sin.readLine();         while (!readline.equals("bye"))
         {
            os.println(readline);
            os.flush();
            System.out.println("圆的半径:"+readline);
            System.out.println("圆的面积:"+is.readLine());
            readline=sin.readLine();
         }
os.close();
         is.close();
         socket.close();
       }
       catch (Exception e)
       {
          System.out.println("Error:"+e);
       }
    }
 }qmjServer:import java.io.*;
import java.net.*;public class Cx2Server
{
   public static void main(String args[]) throws IOException
   {
 int clientnum=0;
      ServerSocket serversocket=null;
      try
      {
         serversocket=new ServerSocket(4700);
      }
catch (IOException e)
      {
         System.out.println("Could not listen on port:4700.");
         System.exit(-1);
      }
      Socket socket=serversocket.accept();     try
      {
      String line;
                BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));
                PrintWriter os=new PrintWriter(socket.getOutputStream());                BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));                int r;
                double mianji;                r=integer.parseint(is.readline);
                mianji=3.14*r*r;                while (!line.equals("bye"))
                {          os.println(mianjistr);
         os.flush();
         System.out.println("圆的面积:"+string.valueof(mianji));
         System.out.println("圆的半径:"+string.valueof(r));
         line=sin.readLine();
              }            
os.close();
                is.close();
         }
         catch (Exception e)
         {
         System.out.println("Error:"+e);
      }    socket.close();
      serversocket.close();
   }
}

Answer 1

public class Cx2Server { public static void main(String args[]) throws IOException
{
ServerSocket serversocket=null;
try
{
serversocket=new ServerSocket(4700);
}
catch (IOException e)
{
System.out.println("Could not listen on port:4700.");
}
Socket socket=serversocket.accept(); try
{
BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter os=new PrintWriter(socket.getOutputStream());
int r = 0;
double mianji;
try
{
r=Integer.parseInt(is.readLine());
}
catch(NumberFormatException e)
{
System.out.println("结束了。");
os.close();
is.close();
socket.close();
serversocket.close();
}

mianji=3.14*r*r;
while (true)
{
os.println(mianji);
os.flush();
} 
}
catch (Exception e)
{
System.out.println("Error:"+e);
socket.close();
serversocket.close();
}
}
}

Answer 2

public class qmjClient { public static void main(String[] args)
{
try
{
Socket socket=new Socket("10.168.53.54",4700); PrintWriter os=new PrintWriter(socket.getOutputStream());
BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream())); BufferedReader sin=new BufferedReader(new InputStreamReader(System.in)); String readline;
readline=sin.readLine(); while (!readline.equals("bye"))
{
os.println(readline);
os.flush();
System.out.println("圆的半径:"+readline);
System.out.println("圆的面积:"+is.readLine());
readline=sin.readLine();
}
sin.close();
os.close();
is.close();
socket.close();
}
catch (Exception e)
{
System.out.println("Error:"+e);
}
}}

Answer 3

给你另一种写法，调试通过的。
//service
package db;
import java.io.*;
import java.net.*;public class ServerTest
{
public static void main(String args[]) throws IOException
{
int clientnum=0;
ServerSocket serversocket=null;
try
{
serversocket=new ServerSocket(1111);
}
catch (IOException e)
{System.exit(-1);
}
Socket socket=serversocket.accept();
System.out.println("COMING-------");try
{
String line=null;
DataInputStream dis=new DataInputStream(socket.getInputStream());
DataOutputStream dos=new DataOutputStream(socket.getOutputStream());
while (true)
{
System.out.println("输出半径");
String r1=dis.readUTF();
if("byte".equals(r1))break;
String s=(3.14*Integer.parseInt(r1)*(Integer.parseInt(r1)))+"";
dos.writeUTF(s);
System.out.println("面积:"+s);
} 
}
catch (Exception e)
{
System.out.println("Error:"+e);
}
}
} 
 
 //client
package db;
import  java.io.*;
import java.net.*;public class ClientTest
{
public static void main(String[] args)
{
try
{ Socket socket=new Socket("10.164.109.31",1111);
DataInputStream dis=new DataInputStream(socket.getInputStream());
DataOutputStream dos=new DataOutputStream(socket.getOutputStream());
    BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));    String readline;
System.out.println("输入半径------");
   while (true)
   {  readline=sin.readLine();
System.out.println("半径："+Integer.parseInt(readline));
dos.writeUTF(readline);
String s=dis.readUTF();
System.out.println("面积："+s);   }}
catch (Exception e)
{
System.out.println("Error:"+e);
}
}
}

Answer 4

那就看看！你那buffereReader中的readLine()方法的问题！！因为他要有一个\n!!你看看有没掉！了