java实现端口转发_Java实现端口映射/转发

男娘i 2022-11-07 04:29 491阅读 0赞

1 importjava.io.IOException;2 importjava.io.InputStream;3 importjava.io.OutputStream;4 importjava.net.ServerSocket;5 importjava.net.Socket;6 importjava.text.SimpleDateFormat;7 import java.util.\*;8

9 public class SimpleForward implementsRunnable \{10 //服务器

11 privateServerSocket server;12 //监听本地端口

13 private int localPort = 1080;14 //目标主机地址

15 private String remoteHostAddr = "0.0.0.0";16 //目标主机端口

17 private int remoteHostPort = 8388;18 //设置超时时间 30s

19 private static int TIMEOUT = 30;20 //客户端列表 用于删除失效连接和超时连接

21 private static HashMap clientList = new HashMap<>();22

23 public static void main(String\[\] args) throwsIOException \{24 //new SimpleForward();

25 new SimpleForward(1234, "127.0.0.1", 1080);26 \}27

28 public SimpleForward() throwsIOException \{29 run();30 \}31

32 public SimpleForward(int localPort, String remoteHostAddr, int remoteHostPort) throwsIOException \{33 this.localPort =localPort;34 this.remoteHostAddr =remoteHostAddr;35 this.remoteHostPort =remoteHostPort;36 run();37 \}38

39 @Override40 public voidrun() \{41 try\{42 this.server = new ServerSocket(this.localPort);43 System.out.println("服务器开启成功");44 System.out.println("监听端口 : " + this.localPort);45 \} catch(IOException e) \{46 System.out.println("服务器开启失败");47 System.out.println(e.getMessage());48 System.out.println("退出运行");49 return;50 \}51 //自动清除失效连接和超时连接

52 new Thread(newTerminal()).start();53 new Thread(newAutoDestroy()).start();54 while (true) \{55 Socket socket = null;56 Socket remoteHost = null;57 try\{58 socket =server.accept();59 //接收到请求就把socket扔进map,value为刷新时间

60 clientList.put(socket, newDate());61 String address =socket.getRemoteSocketAddress().toString();62 System.out.println("新连接 ： " +address);63 //建立与目标主机的连接

64 remoteHost = new Socket(this.remoteHostAddr, this.remoteHostPort);65 System.out.println("连接地址 : " + this.remoteHostAddr + ":" + this.remoteHostPort);66 //端口转发

67 new Thread(newSwitch(socket, remoteHost, remoteHost.getInputStream(), socket.getOutputStream())).start();68 new Thread(newSwitch(socket, remoteHost, socket.getInputStream(), remoteHost.getOutputStream())).start();69 \} catch(IOException e) \{70 System.out.println("连接异常");71 System.out.println(e.getMessage());72 close(socket);73 close(remoteHost);74 \}75 \}76 \}77

78 private voidclose(Socket socket) \{79 try\{80 if (socket != null) \{81 socket.close();82 \}83 \} catch(IOException e) \{84 e.printStackTrace();85 \}86 \}87

88 //用于端口转发

89 private class Switch implementsRunnable \{90 privateSocket host;91 privateSocket remoteHost;92 privateInputStream in;93 privateOutputStream out;94

95 Switch(Socket host, Socket remoteHost, InputStream in, OutputStream out) \{96 this.host =host;97 this.remoteHost =remoteHost;98 this.in =in;99 this.out =out;100 \}101

102 @Override103 public voidrun() \{104 int length = 0;105 byte\[\] buffer = new byte\[1024\];106 try\{107 while (!host.isClosed() && (length = in.read(buffer)) > -1) \{108 clientList.put(host, newDate());109 out.write(buffer, 0, length);110 \}111 \} catch(IOException e) \{112 System.out.println("连接关闭");113 \} finally\{114 close(host);115 close(remoteHost);116 \}117 \}118 \}119

120 //用于清除失效连接和超时连接

121 private class AutoDestroy implementsRunnable \{122

123 @Override124 public voidrun() \{125 Timer timer = newTimer();126 timer.schedule(newTimerTask() \{127 @Override128 public voidrun() \{129 List list = new LinkedList<>();130 System.out.println("开始扫描失效与超时连接");131 Date start = newDate();132 for(Socket socket : clientList.keySet()) \{133 Date lastTime =clientList.get(socket);134 long time = new Date().getTime() -lastTime.getTime();135 if (socket.isClosed() || time / 1000 >=TIMEOUT) \{136 list.add(socket);137 \}138 \}139 System.out.println("找到" + list.size() + "个,用时 : " + (new Date().getTime() - start.getTime()) + "毫秒");140 System.out.println("开始清除失效与超时连接");141 for(Socket socket : list) \{142 try\{143 clientList.remove(socket);144 socket.close();145 \} catch(IOException e) \{146 e.printStackTrace();147 \}148 \}149 System.out.println("当前连接数 : " +clientList.size());150 \}151 \}, 30 \* 1000, 30 \* 1000);152 \}153 \}154

155 private class Terminal implementsRunnable \{156 private ReaderUtil reader = newReaderUtil();157 private String format = "yyyy-MM-dd HH:mm:ss";158 private SimpleDateFormat dateFormat = newSimpleDateFormat(format);159

160 @Override161 public voidrun() \{162 while (!server.isClosed()) \{163 System.out.print("请输入命令 : ");164 String cmd =reader.readKB();165 handler(cmd);166 \}167 \}168

169 private voidhandler(String cmd) \{170 switch(cmd) \{171 case "status":172 System.out.println("当前时间 : " + dateFormat.format(newDate()));173 System.out.println("总连接数 : " +clientList.size());174 for(Socket socket : clientList.keySet()) \{175 long time = new Date().getTime() -clientList.get(socket).getTime();176 System.out.println(" " + time / 1000);177 \}178 break;179 \}180 \}181 \}182 \}