data folder moved under test/data. Test cases added. Code & POM updated.

spring-apache-camel/src/test/data/sampleInputFile/file.txt

@@ -0,0 +1 @@
+THIS IS UPPERCASE CONTENT. this is lowercase content.

spring-apache-camel/src/test/java/org/apache/camel/main/AppTest.java

@@ -0,0 +1,117 @@
+package org.apache.camel.main;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import junit.framework.TestCase;
+
+import org.apache.camel.util.FileUtil;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class AppTest extends TestCase {
+
+	private static final String FILE_NAME = "file.txt";
+	private static final String SAMPLE_INPUT_DIR = "src/test/data/sampleInputFile/";
+	private static final String TEST_INPUT_DIR = "src/test/data/input/";
+	private static final String UPPERCARE_OUTPUT_DIR = "src/test/data/outputUpperCase/";
+	private static final String LOWERCASE_OUTPUT_DIR = "src/test/data/outputLowerCase/";
+
+	@Before
+	public void setUp() throws Exception {
+		// Prepare input file for test
+		copySampleFileToInputDirectory();
+	}
+
+	@After
+	public void tearDown() throws Exception {
+		System.out.println("Deleting the test input and output files...");
+		deleteFile(TEST_INPUT_DIR);
+		deleteFile(LOWERCASE_OUTPUT_DIR);
+		deleteFile(UPPERCARE_OUTPUT_DIR);
+	}
+
+	@Test
+	public final void testMain() throws Exception {
+		App.main(null);
+
+		String inputFileContent = readFileContent(SAMPLE_INPUT_DIR+FILE_NAME);
+		String outputUpperCase = readFileContent(UPPERCARE_OUTPUT_DIR+FILE_NAME);
+		String outputLowerCase = readFileContent(LOWERCASE_OUTPUT_DIR+FILE_NAME);
+		
+		System.out.println("Input File content = ["+inputFileContent+"]");
+		System.out.println("UpperCaseOutput file content = ["+outputUpperCase+"]");
+		System.out.println("LowerCaseOtput file content = ["+outputLowerCase+"]");
+		
+		assertEquals(inputFileContent.toUpperCase(), outputUpperCase);
+		assertEquals(inputFileContent.toLowerCase(), outputLowerCase);
+	}
+
+	private String readFileContent(String path) throws IOException {
+		byte[] encoded = Files.readAllBytes(Paths.get(path));
+		return new String(encoded);
+	}
+
+	private void deleteFile(String path) {
+		try {
+			FileUtil.removeDir(new File(path));
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+
+	/**
+	 * Copy sample input file to input directory.
+	 */
+	private void copySampleFileToInputDirectory() {
+		File sourceFile = new File(SAMPLE_INPUT_DIR + FILE_NAME);
+		File destFile = new File(TEST_INPUT_DIR + FILE_NAME);
+		
+		if (!sourceFile.exists()) {
+			System.out.println("Sample input file not found at location = [" + SAMPLE_INPUT_DIR + FILE_NAME + "]. Please provide this file.");
+		}
+
+		if (!destFile.exists()) {
+			try {
+				System.out.println("Creating input file = [" + TEST_INPUT_DIR + FILE_NAME + "]");
+				
+				File destDir = new File(TEST_INPUT_DIR);
+				if(!destDir.exists()) {
+					destDir.mkdir();
+				}
+				destFile.createNewFile();
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+		FileChannel source = null;
+		FileChannel destination = null;
+
+		try {
+			source = new FileInputStream(sourceFile).getChannel();
+			destination = new FileOutputStream(destFile).getChannel();
+			if (destination != null && source != null) {
+				destination.transferFrom(source, 0, source.size());
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		} finally {
+			try {
+				source.close();
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+			try {
+				destination.close();
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		}
+	}
+}