Question

如何用JAVA代码监听某个开放端口

Answer 1

比如我要监听1234这个端口，代码如下：
String ip = "127.0.0.1";
int port = 1234;
try {
Socket socket = new Socket(ip, port);
socket.setSoTimeout(5539900);
java.io.OutputStream out = socket.getOutputStream();

byte[] date = "hello world".getBytes();
out.write(data);
out.flush();
byte[] buffer = new byte[1024];
int len = -1;
java.io.FileOutputStream fout = new java.io.FileOutputStream(
"d:/response.txt");
java.io.ByteArrayOutputStream bout = new java.io.ByteArrayOutputStream();
java.io.InputStream in = socket.getInputStream();
while ((len = in.read(buffer, 0, buffer.length)) > 0) {
bout.write(buffer, 0, len);
}
in.close();
bout.flush();
bout.close();

byte[] rdata = bout.toByteArray();
System.out.println(new String(rdata));

fout.write(rdata);
fout.flush();
fout.close();
socket.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

服务器端的

ServerSocket ss = new ServerSocket(1234);
Socket socket=null;
BufferedReader in;
PrintWriter out;

while (true) {
socket = ss.accept();
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(),true);
String line = in.readLine();
out.println("you input is :" + line);
out.close();
in.close();
socket.close();
}