BAEL-3909: Moved code to another module (#8931)

core-java-modules/core-java-string-operations-2/src/test/java/com/baeldung/pdf/base64/EncodeDecodeUnitTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.pdf.base64;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class EncodeDecodeUnitTest {
+
+    private static final String IN_FILE = "src/test/resources/input.pdf";
+    private static final String OUT_FILE = "src/test/resources/output.pdf";
+    private static byte[] inFileBytes;
+
+    @BeforeClass
+    public static void fileToByteArray() throws IOException {
+        inFileBytes = Files.readAllBytes(Paths.get(IN_FILE));
+    }
+
+    @Test
+    public void givenJavaBase64_whenEncoded_thenDecodedOK() throws IOException {
+
+        byte[] encoded = java.util.Base64.getEncoder().encode(inFileBytes);
+
+        byte[] decoded = java.util.Base64.getDecoder().decode(encoded);
+
+        writeToFile(OUT_FILE, decoded);
+
+        assertNotEquals(encoded.length, decoded.length);
+        assertEquals(inFileBytes.length, decoded.length);
+
+        assertArrayEquals(decoded, inFileBytes);
+
+    }
+
+    @Test
+    public void givenApacheCommons_givenJavaBase64_whenEncoded_thenDecodedOK() throws IOException {
+
+        byte[] encoded = org.apache.commons.codec.binary.Base64.encodeBase64(inFileBytes);
+
+        byte[] decoded = org.apache.commons.codec.binary.Base64.decodeBase64(encoded);
+
+        writeToFile(OUT_FILE, decoded);
+
+        assertNotEquals(encoded.length, decoded.length);
+        assertEquals(inFileBytes.length, decoded.length);
+
+        assertArrayEquals(decoded, inFileBytes);
+    }
+
+    private void writeToFile(String fileName, byte[] bytes) throws IOException {
+        FileOutputStream fos = new FileOutputStream(fileName);
+        fos.write(bytes);
+        fos.flush();
+        fos.close();
+    }
+}