我正在尝试创建一个简单的客户端 - 服务器应用程序，但是当我执行代码时，我得到一个异常，即客户端无法获取套接字的输入流。请查看我的代码并尝试帮助。谢谢:)
P.S：对于凌乱的代码感到抱歉。将它作为两个不同的应用程序执行。
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.Socket;
public class SimpleClient //implements Runnable
{
private ObjectOutputStream output; // output stream to server
private ObjectInputStream input; // input stream from server
private String message = ""; // message from server
private String chatServer="localhost"; // host server for this application
private Socket client; // socket to communicate with server
public void runClient()
{
try // connect to server, get streams, process connection
{
connectToServer(); // create a Socket to make connection
getStreams(); // get the input and output streams
processConnection(); // process connection
} // end try
catch(IOException ioe)
{
ioe.printStackTrace();
}
finally
{
// closeConnection(); // close connection
} // end finally
}
private void closeConnection()
{
try
{
output.close(); // close output stream
input.close(); // close input stream
client.close(); // close socket
} // end try
catch ( IOException ioException )
{
ioException.printStackTrace();
} // end catch
} // end method closeConnection
private void connectToServer() throws IOException
{
System.out.println( "Attempting connection\n" );
// create Socket to make connection to server
client = new Socket( InetAddress.getByName( chatServer ), 12345 );
// display connection information
System.out.println( "Connected to: " +
client.getInetAddress().getHostName() );
} // end method connectToServer
private void getStreams() throws IOException
{
// set up output stream for objects
output = new ObjectOutputStream( client.getOutputStream() );
output.flush(); // flush output buffer to send header information
// set up input stream for objects
input = new ObjectInputStream( client.getInputStream() );
System.out.println( "\nGot I/O streams\n" );
} // end method getStreams
private void processConnection() throws IOException
{
do {
try // read message and display it
{
message = ( String ) input.readObject(); // read new message
System.out.println( "\n" + message ); // display message
} // end try
catch ( ClassNotFoundException classNotFoundException )
{
System.out.println( "\nUnknown object type received" );
} // end catch
} while ( !message.equals( "SERVER>>> TERMINATE" ) );
} // end method processConnection
public String toString()
{
return "client connected to "+chatServer;
}
public static void main(String []args)
{
SimpleClient c= new SimpleClient();
c.runClient();
}
}
// -------------服务器从这里开始
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
public class SimpleServer //implements Runnable
{
private ObjectOutputStream output; // output stream to client
private ObjectInputStream input; // input stream from client
private ServerSocket server; // server socket
private Socket connection; // connection to client
private int counter=1; //counts connections
ArrayList<SimpleClient> list;
/***
* Runs forever and takes care of alla
*/
public void runServer()
{
try // set up server to receive connections; process connections
{
server = new ServerSocket( 12345, 100 ); // create ServerSocket
while ( true )
{
try
{
waitForConnection(); // wait for a connection
getStreams(); // get input & output streams
processConnection(); // process connection
} // end try
catch ( Exception Exception )
{
System.out.println( "\nSomething bad happened" );
} // end catch
finally
{
closeConnection();
counter++; // close connection
} // end finally
}
}
catch ( IOException ioException )
{
System.out.println("An io error occured while creating a server-socket");
ioException.printStackTrace();
} // end catch
} // end method runServer
/***
* Waits for a client's request for connection
*/
public void waitForConnection()
{
try
{
connection = server.accept();
System.out.println("Client with IP and hostname "+connection.getInetAddress().getHostName());
} catch (IOException ex)
{
System.out.println("An error makes connection impossible");
ex.printStackTrace();
}
}
/***
* Makes the interconnection of client's and server's stream's
*/
public void getStreams()
{
try
{
output=(ObjectOutputStream) connection.getOutputStream();
input=(ObjectInputStream) connection.getInputStream();
output.flush();
System.out.println("Got IO Streams, hell yeah ");
}
catch(IOException ioe)
{
System.out.println("Cannot get streams");
ioe.printStackTrace();
}
}
/***
* Terminates connection
*/
public void closeConnection()
{
try
{
output.flush();
output.close();
input.close();
} catch (IOException ex)
{
ex.printStackTrace();
}
}
/***
* Receives messages from client
*/
public void processConnection()
{
String message="Connection successful";
do // process messages sent from client
{
try // read message and display it
{
message = ( String ) input.readObject(); // read new message
System.out.println("CLIENT>>> "+message);
} // end try
catch ( ClassNotFoundException classNotFoundException )
{
System.out.println( "\nUnknown object type received" );
}
catch(IOException ioe)
{
System.out.println("Cannot receive message from clint");
ioe.printStackTrace();
}
} while ( !message.equals( "CLIENT>>> TERMINATE" ) );
}
/***
* Sends data to client
* @param message
*/
public void sendData(String message)
{
try // send object to client
{
output.writeObject( "SERVER>>> " + message );
output.flush(); // flush output to client
System.out.println("SERVER>>> " + message);
}
catch(IOException ioe)
{
ioe.printStackTrace();
}
}
public String toString()
{
return "this is a simple server with a total of "+counter+" connections";
}
public static void main(String []args)
{
SimpleServer c= new SimpleServer();
c.runServer();
}
}
答案 0 :(得分：2)
您的服务器只是将Socket.getOutputStream（）和Socket.getInputStream（）返回的对象转换为对象流。相反，它必须使用“new ObjectInputStream（）”和“new ObjectOutputStream（）”以与客户端相同的方式构造对象流。记得刷新服务器的ObjectOutputStream。