我一直在使用 IntelliJ 来测试我的 SMTP Java 客户端-服务器协议。我一直在我的客户端 java 文件上测试一些代码以允许我输入文本。
我最终想要实现的输出应该是这样的：
s: 220 [my ip]
c: HELLO [my email]
s: 250 Hello [my email], pleased to meet you
c: MAIL FROM <[my email]>
s: 250 ok
c: RCPT TO: <[test email]>
s: 250 ok
c: DATA
s: 354 End data with <CR><LF>.<CR><LF>
c: Hello loan team,
c: If i don't stay, will i lose my loan?
c: .
s: 250 ok Message accepted for delivery
c: QUIT
s: 221 [my ip] closing connection
当我先运行服务器代码，然后运行客户端代码时，它连接到服务器，但终端中没有输出。即使我在终端中输入一些东西，也没有任何输出，如果客户端代码导致问题，或者服务器代码导致问题，我会感到困惑？只是为了让您知道这两个代码编译和运行都没有错误。
编辑 1：我回到我遵循的教程并输入相同的套接字 ip 和端口，并且客户端代码按照教程运行得非常好。所以我谴责服务器代码是问题所在。主要问题是如何更改 TCPServer 代码以适应简单 SMTP 服务器的要求？
TCPServer.java:
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.io.*;
import java.net.*;
public class TCPServer{
private ServerSocket server;
/**
* The TCPServer constructor initiate the socket
* @param ipAddress
* @param port
* @throws Exception
*/
public TCPServer(String ipAddress, int port) throws Exception {
if (ipAddress != null && !ipAddress.isEmpty())
this.server = new ServerSocket(port, 1, InetAddress.getByName(ipAddress));
else
this.server = new ServerSocket(0, 1, InetAddress.getLocalHost());
}
/**
* The listen method listen to incoming client's datagrams and requests
* @throws Exception
*/
private void listen() throws Exception {
// listen to incoming client's requests via the ServerSocket
//add your code here
String data = null;
Socket client = this.server.accept();
String clientAddress = client.getInetAddress().getHostAddress();
System.out.println("\r\nNew client connection from " + clientAddress);
// print received datagrams from client
//add your code here
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
while ( (data = in.readLine()) != null ) {
System.out.println("\r\nMessage from " + clientAddress + ": " + data);
client.sendUrgentData(1);
}
}
public InetAddress getSocketAddress() {
return this.server.getInetAddress();
}
public int getPort() {
return this.server.getLocalPort();
}
public static void main(String[] args) throws Exception {
// set the server address (IP) and port number
//add your code here
String serverIP = "192.168.1.235"; // local IP address
int port = 8088;
if (args.length > 0) {
serverIP = args[0];
port = Integer.parseInt(args[1]);
}
// call the constructor and pass the IP and port
//add your code here
TCPServer server = new TCPServer(serverIP, port);
System.out.println("\r\nRunning Server: " +
"Host=" + server.getSocketAddress().getHostAddress() +
" Port=" + server.getPort());
server.listen();
}
}
这里是 ClientTester.java
import java.io.*;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import java.util.Scanner;
public class ClientTester{
private Socket tcpSocket;
private InetAddress serverAddress;
private int serverPort;
private Scanner scanner;
/**
* @param serverAddress
* @param serverPort
* @throws Exception
*/
private ClientTester(InetAddress serverAddress, int serverPort) throws Exception {
this.serverAddress = serverAddress;
this.serverPort = serverPort;
//Initiate the connection with the server using Socket.
//For this, creates a stream socket and connects it to the specified port number at the specified IP address.
//add your code here
this.tcpSocket = new Socket(this.serverAddress, this.serverPort);
this.scanner = new Scanner(System.in);
}
/**
* The start method connect to the server and datagrams
* @throws IOException
*/
public static void main(String[] args) throws Exception {
// set the server address (IP) and port number
//add your code here
InetAddress serverIP = InetAddress.getByName("192.168.1.235"); // local IP address
int port = 8088;
if (args.length > 0) {
serverIP = InetAddress.getByName(args[0]);
port = Integer.parseInt(args[1]);
}
// call the constructor and pass the IP and port
//add your code here
ClientTester client = new ClientTester(serverIP, port);
// client.start();
try{
client = new ClientTester(serverIP, port);
System.out.println("\r\n Connected to Server: " + client.tcpSocket.getInetAddress());
BufferedReader stdin;
stdin = new BufferedReader (new InputStreamReader (System.in));
InputStream is = client.tcpSocket.getInputStream ();
BufferedReader sockin;
sockin = new BufferedReader (new InputStreamReader (is));
OutputStream os = client.tcpSocket.getOutputStream();
PrintWriter sockout;
sockout = new PrintWriter (os, true);
System.out.println ("S:" + sockin.readLine ());
while (true){
System.out.print ("C:");
String cmd = stdin.readLine ();
sockout.println (cmd);
String reply = sockin.readLine ();
System.out.println ("S:" + reply);
if (cmd.toLowerCase ().startsWith ("data") &&
reply.substring (0, 3).equals ("354"))
{
do
{
cmd = stdin.readLine ();
if (cmd != null && cmd.length () > 1 &&
cmd.charAt (0) == '.')
cmd = "."; // Must be no chars after . char.
sockout.println (cmd);
if (cmd.equals ("."))
break;
}
while (true);
// Read a reply string from the SMTP server program.
reply = sockin.readLine ();
// Display the first line of this reply string.
System.out.println ("S:" + reply);
continue;
}
// If the QUIT command was entered, quit.
if (cmd.toLowerCase ().startsWith ("quit"))
break;
}
}
catch (IOException e)
{
System.out.println (e.toString ());
}
finally
{
try
{
// Attempt to close the client socket.
if (client != null)
client.tcpSocket.close();
}
catch (IOException e)
{
}
}
}
}
希望我所写的内容对我遇到的问题有所了解。