[BAEL-13505] Move articles out of core-java part 1

core-java-modules/core-java-networking-2/README.md

@@ -1,3 +1,5 @@
 ### Relevant Articles
 
 - [Checking if a URL Exists in Java](https://www.baeldung.com/java-check-url-exists)
+- [Making a JSON POST Request With HttpURLConnection](https://www.baeldung.com/httpurlconnection-post)
+- [Using Curl in Java](https://www.baeldung.com/java-curl)

core-java-modules/core-java-networking-2/src/main/java/com/baeldung/curltojava/JavaCurlExamples.java

@@ -0,0 +1,29 @@
+package com.baeldung.curltojava;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class JavaCurlExamples {
+
+    public static String inputStreamToString(InputStream inputStream) {
+        final int bufferSize = 8 * 1024;
+        byte[] buffer = new byte[bufferSize];
+        final StringBuilder builder = new StringBuilder();
+        try (BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream, bufferSize)) {
+            while (bufferedInputStream.read(buffer) != -1) {
+                builder.append(new String(buffer));
+            }
+        } catch (IOException ex) {
+            Logger.getLogger(JavaCurlExamples.class.getName()).log(Level.SEVERE, null, ex);
+        }
+        return builder.toString();
+    }
+
+    public static void consumeInputStream(InputStream inputStream) {
+        inputStreamToString(inputStream);
+    }
+
+}

core-java-modules/core-java-networking-2/src/main/java/com/baeldung/urlconnection/PostJSONWithHttpURLConnection.java

@@ -0,0 +1,46 @@
+package com.baeldung.urlconnection;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class PostJSONWithHttpURLConnection {
+	
+	public static void main (String []args) throws IOException{
+		//Change the URL with any other publicly accessible POST resource, which accepts JSON request body
+		URL url = new URL ("https://reqres.in/api/users");
+		
+		HttpURLConnection con = (HttpURLConnection)url.openConnection();
+		con.setRequestMethod("POST");
+		
+		con.setRequestProperty("Content-Type", "application/json; utf-8");
+		con.setRequestProperty("Accept", "application/json");
+		
+		con.setDoOutput(true);
+		
+		//JSON String need to be constructed for the specific resource. 
+		//We may construct complex JSON using any third-party JSON libraries such as jackson or org.json
+		String jsonInputString = "{\"name\": \"Upendra\", \"job\": \"Programmer\"}";
+		
+		try(OutputStream os = con.getOutputStream()){
+			byte[] input = jsonInputString.getBytes("utf-8");
+			os.write(input, 0, input.length);			
+		}
+
+		int code = con.getResponseCode();
+		System.out.println(code);
+		
+		try(BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream(), "utf-8"))){
+			StringBuilder response = new StringBuilder();
+			String responseLine = null;
+			while ((responseLine = br.readLine()) != null) {
+				response.append(responseLine.trim());
+			}
+			System.out.println(response.toString());
+		}
+	}
+
+}

core-java-modules/core-java-networking-2/src/test/java/com/baeldung/curltojava/JavaCurlExamplesLiveTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.curltojava;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class JavaCurlExamplesLiveTest {
+
+    @Test
+    public void givenCommand_whenCalled_thenProduceZeroExitCode() throws IOException {
+        String command = "curl -X GET https://postman-echo.com/get?foo1=bar1&foo2=bar2";
+        ProcessBuilder processBuilder = new ProcessBuilder(command.split(" "));
+        processBuilder.directory(new File("/home/"));
+        Process process = processBuilder.start();
+        InputStream inputStream = process.getInputStream();
+        // Consume the inputStream so the process can exit
+        JavaCurlExamples.consumeInputStream(inputStream);
+        int exitCode = process.exitValue();
+        
+        Assert.assertEquals(0, exitCode);
+    }
+    
+    @Test
+    public void givenNewCommands_whenCalled_thenCheckIfIsAlive() throws IOException {
+        String command = "curl -X GET https://postman-echo.com/get?foo1=bar1&foo2=bar2";
+        ProcessBuilder processBuilder = new ProcessBuilder(command.split(" "));
+        processBuilder.directory(new File("/home/"));
+        Process process = processBuilder.start();
+        
+        // Re-use processBuilder
+        processBuilder.command(new String[]{"newCommand", "arguments"});
+        
+        Assert.assertEquals(true, process.isAlive());
+    }
+
+    @Test
+    public void whenRequestPost_thenCheckIfReturnContent() throws IOException {
+        String command = "curl -X POST https://postman-echo.com/post --data foo1=bar1&foo2=bar2";
+        Process process = Runtime.getRuntime().exec(command);
+        
+        // Get the POST result
+        String content = JavaCurlExamples.inputStreamToString(process.getInputStream());
+
+        Assert.assertTrue(null != content && !content.isEmpty());
+    }
+
+}