2021-08-11

gradle/wrapper/gradle-wrapper.properties

@@ -9,4 +9,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 distributionUrl=https\://services.gradle.org/distributions/gradle-7.1.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
+zipStorePath=wrapper/dists

network/build.gradle.kts

@@ -0,0 +1,14 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+plugins {
+    id("elex-java")
+}
+
+dependencies {
+
+}

network/logback.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Examples for Java
+  ~
+  ~ Copyright (c) 2021. Elex. All Rights Reserved.
+  ~ https://www.elex-project.com/
+  -->
+
+<configuration>
+
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="TRACE">
+		<appender-ref ref="CONSOLE" />
+	</root>
+</configuration>

network/src/main/java/kr/pe/elex/examples/http/HttpSample.java

@@ -0,0 +1,91 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.http;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+
+@Slf4j
+public class HttpSample {
+	public static void main(String... args) throws IOException {
+		requestGet();
+	}
+
+	public static void requestGet() throws IOException {
+		URL url = new URL("https://www.google.com/");
+		HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+		connection.setRequestMethod("GET");
+		connection.setDoInput(true);
+		connection.setDoOutput(false);
+		connection.setConnectTimeout(25000);
+		connection.setUseCaches(false);
+
+		// 연결
+		connection.connect();
+
+		// 응답 처리
+		System.out.println("STATUS: " + connection.getResponseCode());
+		connection.getHeaderFields().forEach((key, list) -> {
+			System.out.print(key + ": ");
+			list.forEach(item -> {
+				System.out.print(item + " ");
+			});
+			System.out.println();
+		});
+		try (BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
+			reader.lines().forEachOrdered(line -> {
+				System.out.println(line);
+			});
+		}
+		connection.disconnect();
+	}
+
+	public static void requestPost() throws IOException {
+		URL url = new URL("https://www.google.com/");
+		byte[] data = "Hello".getBytes(StandardCharsets.UTF_8);
+		HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+		connection.setRequestMethod("POST");
+		connection.setDoInput(true);
+		connection.setDoOutput(true);
+		connection.setRequestProperty("Content-Type", "text/plain");
+		connection.setFixedLengthStreamingMode(data.length);
+		connection.setConnectTimeout(25000);
+		connection.setUseCaches(false);
+
+		// 연결
+		connection.connect();
+
+		// 요청 바디 전송
+		OutputStream os = connection.getOutputStream();
+		os.write(data);
+		os.flush();
+
+		// 응답 처리
+		System.out.println("STATUS: " + connection.getResponseCode());
+		connection.getHeaderFields().forEach((key, list) -> {
+			System.out.print(key + ": ");
+			list.forEach(item -> {
+				System.out.print(item + " ");
+			});
+			System.out.println();
+		});
+		try (BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
+			reader.lines().forEachOrdered(line -> {
+				System.out.println(line);
+			});
+		}
+		connection.disconnect();
+	}
+}

network/src/main/java/kr/pe/elex/examples/multicast/MulticastUdpClientSample.java

@@ -0,0 +1,36 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.multicast;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.MulticastSocket;
+import java.nio.charset.StandardCharsets;
+
+@Slf4j
+public class MulticastUdpClientSample {
+	public static void main(String... args) throws IOException {
+		MulticastSocket socket = new MulticastSocket(18888);
+		InetAddress group = InetAddress.getByName("224.0.0.1");
+		socket.joinGroup(group);
+
+		// 수신
+		byte[] buf = new byte[256];
+		DatagramPacket packet = new DatagramPacket(buf, buf.length);
+		socket.receive(packet);
+		String received = new String(packet.getData(), 0, packet.getLength());
+		log.info("Rx: {}", received);
+
+		socket.leaveGroup(group);
+		socket.close();
+	}
+}

network/src/main/java/kr/pe/elex/examples/multicast/MulticastUdpServerSample.java

@@ -0,0 +1,51 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.multicast;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.MulticastSocket;
+import java.nio.charset.StandardCharsets;
+
+@Slf4j
+public class MulticastUdpServerSample {
+	public static void main(String... args) throws IOException {
+		MulticastSocket socket = new MulticastSocket();
+
+		/*
+		IPv4 multicast addresses are defined by the leading address bits of 1110,
+		originating from the classful network design of the early Internet when this group of addresses
+		was designated as Class D. The Classless Inter-Domain Routing (CIDR) prefix of this group is 224.0.0.0/4.
+		The group includes the addresses from 224.0.0.0 to 239.255.255.255.
+
+		A multicast group is specified by a class D IP address and by a standard UDP port number.
+		Class D IP addresses are in the range 224.0.0.0 to 239.255.255.255, inclusive.
+		The address 224.0.0.0 is reserved and should not be used.
+
+		 */
+		for (int i = 0; i < 20; i++) {
+			// 발신
+			InetAddress group = InetAddress.getByName("224.0.0.1");
+			byte[] data = ("Hello~! " + i).getBytes(StandardCharsets.UTF_8);
+			DatagramPacket packet = new DatagramPacket(data, data.length, group, 18888);
+			socket.send(packet);
+			log.info("Tx: {}", new String(packet.getData()));
+
+			try {
+				Thread.sleep(1000);
+			} catch (InterruptedException e) {
+				log.error("Oops~!", e);
+			}
+		}
+
+		socket.disconnect();
+	}
+}

network/src/main/java/kr/pe/elex/examples/new_http/Sample.java

@@ -0,0 +1,44 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.new_http;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+@Slf4j
+public class Sample {
+	public static void main(String... args) throws IOException, InterruptedException {
+		HttpClient httpClient = HttpClient.newBuilder()
+				.version(HttpClient.Version.HTTP_2)
+				.build();
+
+		// GET
+		HttpRequest request = HttpRequest.newBuilder()
+				.GET()
+				.uri(URI.create("https://www.google.com/"))
+				.header("X-Header", "Something")
+				.build();
+		HttpResponse<String> response = httpClient
+				.send(request, HttpResponse.BodyHandlers.ofString());
+
+		System.out.println(response.body());
+
+		// POST
+		request = HttpRequest.newBuilder()
+				.POST(HttpRequest.BodyPublishers.ofString("Hello"))
+				.uri(URI.create("https://www.examples.com/"))
+				.build();
+		response = httpClient
+				.send(request, HttpResponse.BodyHandlers.ofString());
+	}
+}

network/src/main/java/kr/pe/elex/examples/socket/SocketClientSample.java

@@ -0,0 +1,24 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.socket;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.Socket;
+
+@Slf4j
+public class SocketClientSample {
+	public static void main(String... args) throws IOException {
+		Socket socket = new Socket("localhost", 18188);
+		// socket.getInputStream();
+		// socket.getOutputStream();
+
+		socket.close();
+	}
+}

network/src/main/java/kr/pe/elex/examples/socket/SocketServerSample.java

@@ -0,0 +1,40 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.socket;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.List;
+
+@Slf4j
+public class SocketServerSample {
+	private List<Socket> clients = new ArrayList<>();
+	private ServerSocket socket;
+
+	public void open(int port) throws IOException {
+		socket = new ServerSocket(port);
+
+		while (!socket.isClosed()) {
+			try {
+				Socket client = socket.accept();
+				clients.add(client);
+
+			} catch (Throwable e) {
+				log.error("Oops!", e);
+			}
+		}
+	}
+
+	public static void main(String... args){
+
+	}
+}

network/src/main/java/kr/pe/elex/examples/udp/UdpClientSample.java

@@ -0,0 +1,36 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.udp;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.nio.charset.StandardCharsets;
+
+@Slf4j
+public class UdpClientSample {
+	public static void main(String... args) throws IOException {
+		DatagramSocket socket = new DatagramSocket();
+		//socket.
+		// 발신
+		byte[] buf = "Hi~ there.".getBytes(StandardCharsets.UTF_8);
+		DatagramPacket packet = new DatagramPacket(buf, buf.length,
+				InetAddress.getByName("localhost"), 18888);
+		socket.send(packet);
+
+		// 수신
+		buf = new byte[256];
+		packet = new DatagramPacket(buf, buf.length);
+		socket.receive(packet);
+		String received = new String(packet.getData(), 0, packet.getLength());
+		log.info("Rx: {}", received);
+	}
+}

network/src/main/java/kr/pe/elex/examples/udp/UdpServerSample.java

@@ -0,0 +1,41 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.udp;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+@Slf4j
+public class UdpServerSample {
+	public static void main(String... args) throws IOException {
+		DatagramSocket socket = new DatagramSocket(18888);
+
+		// 수신
+		byte[] buf = new byte[256];
+		DatagramPacket packet = new DatagramPacket(buf, buf.length);
+		socket.receive(packet);
+
+		log.info("Rx: {}", new String(Arrays.copyOfRange(buf,packet.getOffset(),packet.getLength())));
+
+		// 발신
+		InetAddress address = packet.getAddress();
+		int port = packet.getPort();
+		byte[] resp = "Hello~!".getBytes(StandardCharsets.UTF_8);
+		packet = new DatagramPacket(resp, resp.length, address, port);
+		socket.send(packet);
+
+
+	}
+}

network/src/main/java/kr/pe/elex/examples/url/UrlSample.java

@@ -0,0 +1,54 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples.url;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+
+@Slf4j
+public class UrlSample {
+	public static void readFromUrl() throws IOException {
+		URL url = new URL("https://www.example.com/");
+		try (BufferedReader in = new BufferedReader(
+				new InputStreamReader(url.openStream()))) {
+			String inputLine;
+			while ((inputLine = in.readLine()) != null){
+				System.out.println(inputLine);
+			}
+			//in.close();
+		}
+
+
+	}
+	public static void writeToUrl() throws IOException {
+		URL url = new URL("https://www.example.com/");
+		URLConnection connection = url.openConnection();
+		connection.setDoOutput(true);
+		connection.connect();
+
+		try(OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());
+		    BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()))){
+			// write
+			out.write("Hello~");
+
+			// read
+			String inputLine;
+			while ((inputLine = in.readLine()) != null){
+				System.out.println(inputLine);
+			}
+		}
+
+	}
+}

network/src/test/java/kr/pe/elex/examples/ExecutorTest.java

@@ -0,0 +1,14 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class ExecutorTest {
+}

settings.gradle.kts

@@ -12,5 +12,5 @@ include(
     "ssh",
     "web-socket-servlet", "web-socket-client",
     "thread", "hibernate", "jdbc-sqlite",
-    "xml", "jackson", "jsoup", "markdown"
+    "xml", "jackson", "jsoup", "markdown", "network"
 )

thread/src/main/java/kr/pe/elex/examples/Synchronizing.java

@@ -0,0 +1,48 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class Synchronizing {
+	public static void main(String... args) {
+		final Rabbit rabbit = new Rabbit();
+
+		new Thread() {
+			@Override
+			public void run() {
+				rabbit.hello();
+			}
+		}.start();
+		new Thread() {
+			@Override
+			public void run() {
+				rabbit.count();
+			}
+		}.start();
+		new Thread() {
+			@Override
+			public void run() {
+				rabbit.hello();
+			}
+		}.start();
+	}
+
+	static class Rabbit {
+		public synchronized void count() {
+			for (int i = 0; i < 100; i++) {
+				System.out.println("Rabbit says " + i + ".");
+			}
+		}
+
+		public synchronized void hello() {
+			System.out.println("Rabbit says 'Hello'.");
+		}
+	}
+}