我想测试我自己的电子邮件客户端，以测试向我自己的计算机上的模拟地址发送模拟电子邮件，但我正在努力解决如何在我自己的计算机中实现 SMTP 服务器代码。
到目前为止，我已经知道了，所以当我运行服务器和客户端时，它们都可以在我的 IP 上连接在一起，但现在我正在努力在服务器中实现电子邮件部分以便客户端进行通信到.
整个项目的最终输出应该看起来像这样：
S: 220 [my ip]
C: HELLO [my ip]
S: 250 Hello [email protected], pleased to meet you
C: MAIL FROM: <[email protected]>
S: 250 ok
C: RCPT TO: <[email protected]>
S: 250 ok
C: DATA
S: 354 End data with <CR><LF>.<CR><LF>
C: Hello ,
C: How are you today?
C: .
S: 250 ok Message accepted for delivery
C: QUIT
S: 221 [my ip] closing connection
当我在客户端代码中使用 Google 的 SMTP 服务器
smtp.google.com这是服务器代码：
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
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();
}
}
这是我的客户端代码：
import java.io.*;
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
//IP: 192.168.1.235
//Port: 8088
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);
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)
{
}
}
}
}
希望这对我想要实现的目标有一定意义。
不要编写自己的 SMTP 服务器。有许多产品的功能远远超过您想要花时间实现的功能。我用的是这个：
https://github.com/gessnerfl/fake-smtp-server
它有一个 html 界面，可让您查看它收到的电子邮件。