alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.io;

import junit.framework.TestCase;

import java.io.IOException;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

/**
 * @author Henri Yandell (bayard at apache dot org)
 * @version $Revision: 1.13 $ $Date: 2004/02/29 21:47:07 $
 */
public class EndianUtilsTest extends TestCase {

    public EndianUtilsTest(String name) {
        super(name);
    }

    public void testSwapShort() {
        assertEquals( (short) 0, EndianUtils.swapShort( (short) 0 ) );
        assertEquals( (short) 0x0201, EndianUtils.swapShort( (short) 0x0102 ) );
        assertEquals( (short) 0xffff, EndianUtils.swapShort( (short) 0xffff ) );
        assertEquals( (short) 0x0102, EndianUtils.swapShort( (short) 0x0201 ) );
    }

    public void testSwapInteger() {
        assertEquals( 0, EndianUtils.swapInteger( 0 ) );
        assertEquals( 0x04030201, EndianUtils.swapInteger( 0x01020304 ) );
        assertEquals( 0x01000000, EndianUtils.swapInteger( 0x00000001 ) );
        assertEquals( 0x00000001, EndianUtils.swapInteger( 0x01000000 ) );
        assertEquals( 0x11111111, EndianUtils.swapInteger( 0x11111111 ) );
        assertEquals( 0xabcdef10, EndianUtils.swapInteger( 0x10efcdab ) );
        assertEquals( 0xab, EndianUtils.swapInteger( 0xab000000 ) );
    }

    public void testSwapLong() {
        assertEquals( 0, EndianUtils.swapLong( 0 ) );
        assertEquals( 0x0807060504030201L, EndianUtils.swapLong( 0x0102030405060708L ) );
        assertEquals( 0xffffffffffffffffL, EndianUtils.swapLong( 0xffffffffffffffffL ) );
        assertEquals( 0xab, EndianUtils.swapLong( 0xab00000000000000L ) );
    }

    public void testSwapFloat() {
        assertEquals( 0.0f, EndianUtils.swapFloat( 0.0f ), 0.0 );
        float f1 = Float.intBitsToFloat( 0x01020304 );
        float f2 = Float.intBitsToFloat( 0x04030201 );
        assertEquals( f2, EndianUtils.swapFloat( f1 ), 0.0 );
    }

    public void testSwapDouble() {
        assertEquals( 0.0, EndianUtils.swapDouble( 0.0 ), 0.0 );
        double d1 = Double.longBitsToDouble( 0x0102030405060708L );
        double d2 = Double.longBitsToDouble( 0x0807060504030201L );
        assertEquals( d2, EndianUtils.swapDouble( d1 ), 0.0 );
    }

    /**
     * Tests all swapXxxx methods for symmetry when going from one endian 
     * to another and back again. 
     */
    public void testSymmetry() {
        assertEquals( (short) 0x0102, EndianUtils.swapShort( EndianUtils.swapShort( (short) 0x0102 ) ) );
        assertEquals( 0x01020304, EndianUtils.swapInteger( EndianUtils.swapInteger( 0x01020304 ) ) );
        assertEquals( 0x0102030405060708L, EndianUtils.swapLong( EndianUtils.swapLong( 0x0102030405060708L ) ) );
        float f1 = Float.intBitsToFloat( 0x01020304 );
        assertEquals( f1, EndianUtils.swapFloat( EndianUtils.swapFloat( f1 ) ), 0.0 );
        double d1 = Double.longBitsToDouble( 0x0102030405060708L );
        assertEquals( d1, EndianUtils.swapDouble( EndianUtils.swapDouble( d1 ) ), 0.0 );
    }

    public void testReadSwappedShort() throws IOException {
        byte[] bytes = new byte[] { 0x02, 0x01 };
        assertEquals( 0x0102, EndianUtils.readSwappedShort( bytes, 0 ) );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( 0x0102, EndianUtils.readSwappedShort( input ) );
    }

    public void testWriteSwappedShort() throws IOException {
        byte[] bytes = new byte[2];
        EndianUtils.writeSwappedShort( bytes, 0, (short) 0x0102 );
        assertEquals( 0x02, bytes[0] );
        assertEquals( 0x01, bytes[1] );

        ByteArrayOutputStream baos = new ByteArrayOutputStream(2);
        EndianUtils.writeSwappedShort( baos, (short) 0x0102 );
        bytes = baos.toByteArray();
        assertEquals( 0x02, bytes[0] );
        assertEquals( 0x01, bytes[1] );
    }

    public void testReadSwappedUnsignedShort() throws IOException {
        byte[] bytes = new byte[] { 0x02, 0x01 };
        assertEquals( 0x00000102, EndianUtils.readSwappedUnsignedShort( bytes, 0 ) );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( 0x00000102, EndianUtils.readSwappedUnsignedShort( input ) );
    }

    public void testReadSwappedInteger() throws IOException {
        byte[] bytes = new byte[] { 0x04, 0x03, 0x02, 0x01 };
        assertEquals( 0x01020304, EndianUtils.readSwappedInteger( bytes, 0 ) );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( 0x01020304, EndianUtils.readSwappedInteger( input ) );
    }

    public void testWriteSwappedInteger() throws IOException {
        byte[] bytes = new byte[4];
        EndianUtils.writeSwappedInteger( bytes, 0, 0x01020304 );
        assertEquals( 0x04, bytes[0] );
        assertEquals( 0x03, bytes[1] );
        assertEquals( 0x02, bytes[2] );
        assertEquals( 0x01, bytes[3] );

        ByteArrayOutputStream baos = new ByteArrayOutputStream(4);
        EndianUtils.writeSwappedInteger( baos, 0x01020304 );
        bytes = baos.toByteArray();
        assertEquals( 0x04, bytes[0] );
        assertEquals( 0x03, bytes[1] );
        assertEquals( 0x02, bytes[2] );
        assertEquals( 0x01, bytes[3] );
    }

    public void testReadSwappedUnsignedInteger() throws IOException {
        byte[] bytes = new byte[] { 0x04, 0x03, 0x02, 0x01 };
        assertEquals( 0x0000000001020304L, EndianUtils.readSwappedUnsignedInteger( bytes, 0 ) );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( 0x0000000001020304L, EndianUtils.readSwappedUnsignedInteger( input ) );
    }

    public void testReadSwappedLong() throws IOException {
        byte[] bytes = new byte[] { 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01 };
        assertEquals( 0x0102030405060708L, EndianUtils.readSwappedLong( bytes, 0 ) );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( 0x0102030405060708L, EndianUtils.readSwappedLong( input ) );
    }

    public void testWriteSwappedLong() throws IOException {
        byte[] bytes = new byte[8];
        EndianUtils.writeSwappedLong( bytes, 0, 0x0102030405060708L );
        assertEquals( 0x08, bytes[0] );
        assertEquals( 0x07, bytes[1] );
        assertEquals( 0x06, bytes[2] );
        assertEquals( 0x05, bytes[3] );
        assertEquals( 0x04, bytes[4] );
        assertEquals( 0x03, bytes[5] );
        assertEquals( 0x02, bytes[6] );
        assertEquals( 0x01, bytes[7] );

        ByteArrayOutputStream baos = new ByteArrayOutputStream(8);
        EndianUtils.writeSwappedLong( baos, 0x0102030405060708L );
        bytes = baos.toByteArray();
        assertEquals( 0x08, bytes[0] );
        assertEquals( 0x07, bytes[1] );
        assertEquals( 0x06, bytes[2] );
        assertEquals( 0x05, bytes[3] );
        assertEquals( 0x04, bytes[4] );
        assertEquals( 0x03, bytes[5] );
        assertEquals( 0x02, bytes[6] );
        assertEquals( 0x01, bytes[7] );
    }

    public void testReadSwappedFloat() throws IOException {
        byte[] bytes = new byte[] { 0x04, 0x03, 0x02, 0x01 };
        float f1 = Float.intBitsToFloat( 0x01020304 );
        float f2 = EndianUtils.readSwappedFloat( bytes, 0 );
        assertEquals( f1, f2, 0.0 );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( f1, EndianUtils.readSwappedFloat( input ), 0.0 );
    }

    public void testWriteSwappedFloat() throws IOException {
        byte[] bytes = new byte[4];
        float f1 = Float.intBitsToFloat( 0x01020304 );
        EndianUtils.writeSwappedFloat( bytes, 0, f1 );
        assertEquals( 0x04, bytes[0] );
        assertEquals( 0x03, bytes[1] );
        assertEquals( 0x02, bytes[2] );
        assertEquals( 0x01, bytes[3] );

        ByteArrayOutputStream baos = new ByteArrayOutputStream(4);
        EndianUtils.writeSwappedFloat( baos, f1 );
        bytes = baos.toByteArray();
        assertEquals( 0x04, bytes[0] );
        assertEquals( 0x03, bytes[1] );
        assertEquals( 0x02, bytes[2] );
        assertEquals( 0x01, bytes[3] );
    }

    public void testReadSwappedDouble() throws IOException {
        byte[] bytes = new byte[] { 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01 };
        double d1 = Double.longBitsToDouble( 0x0102030405060708L );
        double d2 = EndianUtils.readSwappedDouble( bytes, 0 );
        assertEquals( d1, d2, 0.0 );

        ByteArrayInputStream input = new ByteArrayInputStream(bytes);
        assertEquals( d1, EndianUtils.readSwappedDouble( input ), 0.0 );
    }

    public void testWriteSwappedDouble() throws IOException {
        byte[] bytes = new byte[8];
        double d1 = Double.longBitsToDouble( 0x0102030405060708L );
        EndianUtils.writeSwappedDouble( bytes, 0, d1 );
        assertEquals( 0x08, bytes[0] );
        assertEquals( 0x07, bytes[1] );
        assertEquals( 0x06, bytes[2] );
        assertEquals( 0x05, bytes[3] );
        assertEquals( 0x04, bytes[4] );
        assertEquals( 0x03, bytes[5] );
        assertEquals( 0x02, bytes[6] );
        assertEquals( 0x01, bytes[7] );

        ByteArrayOutputStream baos = new ByteArrayOutputStream(8);
        EndianUtils.writeSwappedDouble( baos, d1 );
        bytes = baos.toByteArray();
        assertEquals( 0x08, bytes[0] );
        assertEquals( 0x07, bytes[1] );
        assertEquals( 0x06, bytes[2] );
        assertEquals( 0x05, bytes[3] );
        assertEquals( 0x04, bytes[4] );
        assertEquals( 0x03, bytes[5] );
        assertEquals( 0x02, bytes[6] );
        assertEquals( 0x01, bytes[7] );
    }

}
... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.