ByteBufferUtils + JUnit Test

marci4 · marci4 · commit 556f2dabf616 · 2017-05-23T09:39:45.000+02:00
diff --git a/src/main/java/org/java_websocket/util/ByteBufferUtils.java b/src/main/java/org/java_websocket/util/ByteBufferUtils.java
@@ -0,0 +1,45 @@
+package org.java_websocket.util;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Utility class for ByteBuffers
+ */
+public class ByteBufferUtils {
+
+	/**
+	 * Private constructor for static class
+	 */
+	private ByteBufferUtils() {
+	}
+
+	/**
+	 * Transfer from one ByteBuffer to another ByteBuffer
+	 *
+	 * @param source the ByteBuffer to copy from
+	 * @param dest   the ByteBuffer to copy to
+	 */
+	public static void transferByteBuffer( ByteBuffer source, ByteBuffer dest ) {
+		if( source == null || dest == null ) {
+			throw new IllegalArgumentException();
+		}
+		int fremain = source.remaining();
+		int toremain = dest.remaining();
+		if( fremain > toremain ) {
+			source.limit( Math.min( fremain, toremain ) );
+			dest.put( source );
+		} else {
+			dest.put( source );
+		}
+
+	}
+
+	/**
+	 * Get a ByteBuffer with zero capacity
+	 *
+	 * @return empty ByteBuffer
+	 */
+	public static ByteBuffer getEmptyByteBuffer() {
+		return ByteBuffer.allocate( 0 );
+	}
+}
diff --git a/src/test/java/org/java_websocket/util/ByteBufferUtilsTest.java b/src/test/java/org/java_websocket/util/ByteBufferUtilsTest.java
@@ -0,0 +1,82 @@
+package org.java_websocket.util;
+
+import org.java_websocket.util.ByteBufferUtils;
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+
+import static org.junit.Assert.*;
+
+/**
+ * JUnit Test for the new ByteBufferUtils class
+ */
+public class ByteBufferUtilsTest {
+
+	private static byte[] smallArray = { 0, -1, -2, -3, -4 };
+	private static byte[] bigArray = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+
+	@Test
+	public void testEmptyByteBufferCapacity() {
+		ByteBuffer byteBuffer = ByteBufferUtils.getEmptyByteBuffer();
+		assertEquals( "capacity must be 0", byteBuffer.capacity(), 0 );
+	}
+
+	@Test
+	public void testEmptyByteBufferLimit() {
+		ByteBuffer byteBuffer = ByteBufferUtils.getEmptyByteBuffer();
+		assertEquals( "limit must be 0", byteBuffer.limit(), 0 );
+	}
+
+	@Test
+	public void testEmptyByteBufferNewObject() {
+		ByteBuffer byteBuffer0 = ByteBufferUtils.getEmptyByteBuffer();
+		ByteBuffer byteBuffer1 = ByteBufferUtils.getEmptyByteBuffer();
+		assertTrue( "Allocated new object", byteBuffer0 != byteBuffer1 );
+	}
+
+	@Test
+	public void testTransferByteBufferSmallToEmpty() {
+		ByteBuffer small = ByteBuffer.wrap( smallArray );
+		ByteBuffer empty = ByteBufferUtils.getEmptyByteBuffer();
+		ByteBufferUtils.transferByteBuffer( small, empty );
+		assertArrayEquals( "Small bytebuffer should not change", small.array(), smallArray );
+		assertEquals( "capacity of the empty bytebuffer should still be 0", empty.capacity(), 0 );
+	}
+
+	@Test
+	public void testTransferByteBufferSmallToBig() {
+		ByteBuffer small = ByteBuffer.wrap( smallArray );
+		ByteBuffer big = ByteBuffer.wrap( bigArray );
+		ByteBufferUtils.transferByteBuffer( small, big );
+		assertArrayEquals( "Small bytebuffer should not change", small.array(), smallArray );
+		assertEquals( big.get( 0 ), smallArray[0] );
+		assertEquals( big.get( 1 ), smallArray[1] );
+		assertEquals( big.get( 2 ), smallArray[2] );
+		assertEquals( big.get( 3 ), smallArray[3] );
+		assertEquals( big.get( 4 ), smallArray[4] );
+		assertEquals( big.get( 5 ), bigArray[5] );
+		assertEquals( big.get( 6 ), bigArray[6] );
+		assertEquals( big.get( 7 ), bigArray[7] );
+		assertEquals( big.get( 8 ), bigArray[8] );
+	}
+
+	@Test
+	public void testTransferByteBufferBigToSmall() {
+		ByteBuffer small = ByteBuffer.wrap( smallArray );
+		ByteBuffer big = ByteBuffer.wrap( bigArray );
+		ByteBufferUtils.transferByteBuffer( big, small );
+		assert ( small.get( 0 ) == bigArray[0] );
+		assert ( small.get( 1 ) == bigArray[1] );
+		assert ( small.get( 2 ) == bigArray[2] );
+		assert ( small.get( 3 ) == bigArray[3] );
+		assert ( small.get( 4 ) == bigArray[4] );
+		assert ( big.array() == bigArray );
+	}
+
+	@Test
+	public void testTransferByteBufferCheckNull() {
+		ByteBuffer source = ByteBufferUtils.getEmptyByteBuffer();
+		ByteBuffer dest = ByteBufferUtils.getEmptyByteBuffer();
+		ByteBufferUtils.transferByteBuffer( source, null );
+	}
+}
