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我在玩一个简单的Client和Server应用程序使用套接字，我试图在控制台打印一条消息，并得到服务器的响应，但什么也没有显示出来，我对套接字相当陌生所以我认为我有一个逻辑错误。这是一个简单的应用程序，我希望客户端提示用户一个命令（在我的情况下，输入字符串，服务器将执行基于'th字符的操作），将其发送到服务器，并显示服务器响应。我很确定我的客户端不正确，有人能指出我为什么不能从客户端控制台写入任何东西。java套接字编程聊天
package socketProgramming;
import java.io.*;
import java.net.*;
public class MyClient {
@SuppressWarnings("resource")
public static void main(String[] args) {
// TODO Auto-generated method stub
Socket socket= new Socket();
BufferedReader in = null;
String msg;
int port = 2222;
try {
System.out.println("CLient wants to connect on port: "+port);
socket = new Socket(InetAddress.getLocalHost().getHostAddress(), port);
System.out.println("The client is connected");
} catch (UnknownHostException e) {
System.exit(1);
} catch (IOException e) {
System.out.println("connect failed");
System.exit(1);
}
try{
BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintStream output = new PrintStream(socket.getOutputStream());
String text = null;
output.print(text);
while ((text = input.readLine()) != null){
System.out.println("Client "+text);
}
socket.close();
System.out.println("Client Exiting");
}
catch(IOException e) {
System.out.println(e);
}}
}
package socketProgramming;
import java.io.*;
import java.net.*;
public class MyServer {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
String msg = "";
ServerSocket sSocket = null;
Socket clientSocket;
int port = 2222;//Integer.parseInt(args[0]);
try{
sSocket = new ServerSocket(port);
} catch(IOException e){
System.out.println(e);
}
while(true){
try {// listen for a connection from client and accept it.
System.out.println("Server is listenning on host: "
+InetAddress.getLocalHost().getHostAddress() +""
+ " and on port: "
+ port);
clientSocket = sSocket.accept();
System.out.println("Connection accepted");
BufferedReader input = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
// PrintWriter out =
// new PrintWriter(clientSocket.getOutputStream(), true);
PrintStream output = new PrintStream(clientSocket.getOutputStream());
msg = input.readLine();
if(msg != null){
if(msg.charAt(12)=='4'){
System.out.println("reading message "+msg+" ");
output.print("Bye");
sSocket.close();
System.out.println("Server exits");
}else{
if(msg.charAt(12)=='0'){
System.out.println("reading message "+msg+" ");
output.print("OK");
}else if (msg.charAt(12)=='1'){
System.out.println("reading message "+msg+" ");
//Should return IP address
output.print(clientSocket.getInetAddress());
}else if (msg.charAt(12)=='2'){
System.out.println("reading message "+msg+" ");
for(int i = 1; i<=10; ++i){
output.print(i);
output.print(" ");
}
}else if (msg.charAt(12)=='3'){
System.out.println("reading message "+msg+" ");
output.print("GOT IT");
}else{
System.out.println("*******************");
}
}
}
sSocket.close();
System.out.println("Server exits");
}
catch(IOException e) {
System.out.println("accept failed");
System.exit(1);
}
System.out.println("Hello world");
}
}
}
你能详细说明谁是想要开始的消息，以及如何？ – Linus
如果他的客户发送类似'CCCCCCCC type0 4567322 X'的东西，因为'12th'字符是0 print'Bye'或任何东西。希望它更清楚一点 – Bobby
嗯，我相信我找到了套接字问题的答案。你可能仍然有问题，因为打印一个'null'字符串会产生一个''null''字符串，但是希望你能诊断任何进一步的问题。 – Linus