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commit bc6cbf59b727923f884167b262002bdce3d852f4
parent eacb5dfe252aad9a4d0ceb52cc94eea380ed40a6
Author: Christos Margiolis <christos@margiolis.net>
Date:   Sat, 15 Jan 2022 22:10:23 +0200

new java code

Diffstat:

Ajava_net/net_programming/EchoClient.java | 37+++++++++++++++++++++++++++++++++++++


Ajava_net/net_programming/EchoServer.java | 37+++++++++++++++++++++++++++++++++++++


Ajava_net/net_programming/HTTPServer.html | 31+++++++++++++++++++++++++++++++


Ajava_net/net_programming/HTTPServer.java | 48++++++++++++++++++++++++++++++++++++++++++++++++


Ajava_net/net_programming/ShowIP.java | 23+++++++++++++++++++++++


Ajava_net/net_programming/UDPClient.java | 41+++++++++++++++++++++++++++++++++++++++++


Ajava_net/net_programming/UDPServer.java | 35+++++++++++++++++++++++++++++++++++


7 files changed, 252 insertions(+), 0 deletions(-)

diff --git a/java_net/net_programming/EchoClient.java b/java_net/net_programming/EchoClient.java
@@ -0,0 +1,37 @@
+import java.net.*;
+import java.io.*;
+
+public class EchoClient {
+	public static void main(String[] args) throws IOException {
+		Socket echosock;
+		PrintWriter out;
+		BufferedReader in, stdin;
+		String input;
+		String hostname = "127.0.0.1";
+		int port = 7777;
+
+		if (args.length == 2) {
+			hostname = args[0];
+			port = Integer.parseInt(args[1]);
+		} else
+			System.err.println("usage: java EchoClient [hostname] [port]");
+		try {
+			echosock = new Socket(hostname, port);
+			out = new PrintWriter(echosock.getOutputStream(), true);
+			in = new BufferedReader(new InputStreamReader(
+			    echosock.getInputStream()));
+			stdin = new BufferedReader(new InputStreamReader(System.in));
+			
+			System.out.print("> ");
+			while ((input = stdin.readLine()) != null) {
+				out.println(input);
+				System.out.println("echo: " + in.readLine());
+				System.out.print("> ");
+			}
+		} catch (UnknownHostException e) {
+			System.err.println("unknown host: " + hostname);
+		} catch (IOException e) {
+			System.err.println("io exception: " + e.getMessage());
+		}
+	}
+}
diff --git a/java_net/net_programming/EchoServer.java b/java_net/net_programming/EchoServer.java
@@ -0,0 +1,37 @@
+import java.net.*;
+import java.io.*;
+
+public class EchoServer {
+	public static void main(String[] args) throws IOException {
+		ServerSocket srvsock;
+		Socket cltsock;
+		BufferedReader in;
+		PrintWriter out;
+		String line;
+		int port = 7777;
+
+		if (args.length == 0)
+			System.err.println("usage: java EchoServer [port]");
+		else
+			port = Integer.parseInt(args[0]);
+		System.out.println("[EchoServer] starting");
+		try {
+			srvsock = new ServerSocket(port);
+			while (true) {
+				cltsock = srvsock.accept();
+				out = new PrintWriter(
+				    cltsock.getOutputStream(), true);
+				in = new BufferedReader(new InputStreamReader(
+				    cltsock.getInputStream()));
+				while ((line = in.readLine()) != null) {
+					if (line.equals("exit"))
+						break;
+					out.println(line);
+				}
+			}
+		} catch (IOException e) {
+			System.err.println("[EchoServer] exception on port " + port);
+			System.err.println(e.getMessage());
+		}
+	}
+}
diff --git a/java_net/net_programming/HTTPServer.html b/java_net/net_programming/HTTPServer.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<title>HTTPServer Test</title>
+	<meta charset="UTF-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1.0">
+</head>
+<body>
+	Example of GET method<br>
+	<form action="http://127.0.0.1:8010" method="GET">
+		Username<input type="text" name="user"><br>
+		Password<input type="text" name="pass"><br>
+		<input type="submit" value="Login"><br>
+	</form>
+
+	<p>Example of POST method</p>
+	<form action="http://127.0.0.1:8010" method="POST">
+		Username<input type="text" name="user"><br>
+		Password<input type="text" name="pass"><br>
+		<input type="submit" value="Login"><br>
+	</form>
+
+	<p>Example of multi-part request</p>
+	<form action="http://127.0.0.1:8010" method="POST" enctype="multipart/form-data">
+		Type your name<input type="text" name="uname"><br>
+		File<input type="file" name="attach1"><br>
+		File<input type="file" name="attach2"><br>
+		<input type="submit" value="Send to server"><br>
+	</form>
+</body>
+</html>
diff --git a/java_net/net_programming/HTTPServer.java b/java_net/net_programming/HTTPServer.java
@@ -0,0 +1,48 @@
+import java.io.*;
+import java.net.*;
+
+class SocketUtils {
+	static final int BUF_LEN = 1024;
+
+	public static String getRequest(Socket sock) throws Exception {
+		StringBuilder reqstr = new StringBuilder();
+		byte[] reqbytes = new byte[BUF_LEN];
+		InputStream in = sock.getInputStream();
+		int n;
+
+		while (true) {
+			n = in.read(reqbytes, 0, BUF_LEN);
+			if (n == -1)
+				break;
+			reqstr.append(new String(reqbytes, 0, n));
+			if (n < BUF_LEN)
+				break;
+		}
+		return reqstr.toString();
+	}
+}
+
+public class HTTPServer {
+	public static void main(String[] args) throws Exception {
+		ServerSocket srvsock = new ServerSocket(8010);
+		Socket sock;
+		String req;
+		PrintWriter pw;
+
+		while (true) {
+			System.out.println("[HTTPServer] waiting for client");
+			sock = srvsock.accept();
+			req = SocketUtils.getRequest(sock);
+			System.out.println("[HTTPServer] obtained request:\n\n" + req);
+			pw = new PrintWriter(sock.getOutputStream());
+
+			pw.println("HTTP/1.0 200 OK");
+			pw.println("Content-type: text/html");
+			pw.println("Server: Java 6.1\n");
+
+			pw.println("<html><body>Hello world</body></html>");
+			pw.close();
+			sock.close();
+		}
+	}
+}
diff --git a/java_net/net_programming/ShowIP.java b/java_net/net_programming/ShowIP.java
@@ -0,0 +1,23 @@
+import java.net.*;
+
+public class ShowIP {
+	public static void main(String[] args) throws Exception {
+		InetAddress[] addr;
+		String hostname = "";
+
+		try {
+			hostname = args[0];
+			addr = InetAddress.getAllByName(hostname);
+
+			for (int i = 0; i < addr.length; i++)
+				System.out.println(i + "\t" + hostname + ": " +
+				    addr[i].toString());
+		} catch (ArrayIndexOutOfBoundsException e) {
+			System.err.println("usage: java ShowIP <hostname>");
+			System.exit(1);
+		} catch (UnknownHostException e) {
+			System.err.println("unknown host: " + hostname);
+			System.exit(1);
+		}
+	}
+}
diff --git a/java_net/net_programming/UDPClient.java b/java_net/net_programming/UDPClient.java
@@ -0,0 +1,41 @@
+import java.io.*;
+import java.net.*;
+
+public class UDPClient {
+	public static void main(String[] args) throws Exception {
+		DatagramSocket cltsock;
+		DatagramPacket sendpack, recvpack;
+		InetAddress addr;
+		BufferedReader input;
+		String msg, srvresp;
+		String hostname = "127.0.0.1";
+		byte[] senddata = new byte[1024];
+		byte[] recvdata = new byte[1024];
+		int port = 8888;
+
+		if (args.length == 2) {
+			hostname = args[0];
+			port = Integer.parseInt(args[1]);
+		} else
+			System.out.println("usage: java UDPClient [hostname] [port]");
+		System.out.print("> ");
+		input = new BufferedReader(new InputStreamReader(System.in));
+		cltsock = new DatagramSocket();
+		cltsock.setSoTimeout(1000);
+		addr = InetAddress.getByName(hostname);
+		msg = input.readLine();
+		senddata = msg.getBytes();
+		sendpack = new DatagramPacket(senddata, senddata.length, addr, port);
+		cltsock.send(sendpack);
+		recvpack = new DatagramPacket(recvdata, recvdata.length);
+
+		try {
+			cltsock.receive(recvpack);
+			srvresp = new String(recvpack.getData());
+			System.out.println("server response: " + srvresp);
+		} catch (SocketTimeoutException e) {
+			System.err.println("timeout" + e);
+		}
+		cltsock.close();
+	}
+}
diff --git a/java_net/net_programming/UDPServer.java b/java_net/net_programming/UDPServer.java
@@ -0,0 +1,35 @@
+import java.net.*;
+
+public class UDPServer {
+	public static void main(String[] args) throws Exception {
+		DatagramSocket srvsock;
+		DatagramPacket sendpack, recvpack;
+		InetAddress addr;
+		String msg;
+		byte[] senddata = new byte[1024];
+		byte[] recvdata = new byte[1024];
+		int port = 8888, recvport;
+
+		if (args.length == 0)
+			System.out.println("usage: java UDPServer [port]");
+		else
+			port = Integer.parseInt(args[0]);
+		System.out.println("[UDPServer] starting");
+		srvsock = new DatagramSocket(port);
+
+		while (true) {
+			recvpack = new DatagramPacket(recvdata, recvdata.length);
+			srvsock.receive(recvpack);
+			msg = new String(recvpack.getData(), 0,
+			    recvpack.getLength());
+			
+			System.out.println("your message: " + msg);
+			addr = recvpack.getAddress();
+			recvport = recvpack.getPort();
+			senddata = msg.getBytes();
+			sendpack = new DatagramPacket(senddata,
+			    senddata.length, addr, recvport);
+			srvsock.send(sendpack);
+		}
+	}
+}