如何用JAVA代码监听某个开放端口

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()

}

你可以在JSP页面用这三个方法

request.getRemoteAddr()//获取远程IP

request.getRemoteUser()//获取远程用户

request.getRemoteHost()//获取远程主机

可以写方法,请看java.net包下的类.

java.net.InetAddress

java.net.InetSocketAddress

获取IP,主机和端口.

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