Commons IO example source code file (ByteOrderMark.java)

This example Commons IO source code file (ByteOrderMark.java) 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.

Java - Commons IO tags/keywords

byteordermark, byteordermark, illegalargumentexception, io, no, override, override, serializable, string, string, stringbuilder, stringbuilder, utf_16be, utf_16le, utf_8

The Commons IO ByteOrderMark.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 java.io.Serializable;

/**
 * Byte Order Mark (BOM) representation -
 * see {@link org.apache.commons.io.input.BOMInputStream}.
 *
 * @see org.apache.commons.io.input.BOMInputStream
 * @see <a href="http://en.wikipedia.org/wiki/Byte_order_mark">Wikipedia - Byte Order Mark
 * @version $Id: ByteOrderMark.java 1005099 2010-10-06 16:13:01Z niallp $
 * @since Commons IO 2.0
 */
public class ByteOrderMark implements Serializable {

    private static final long serialVersionUID = 1L;

    /** UTF-8 BOM */
    public static final ByteOrderMark UTF_8    = new ByteOrderMark("UTF-8",    0xEF, 0xBB, 0xBF);
    /** UTF-16BE BOM (Big Endian) */
    public static final ByteOrderMark UTF_16BE = new ByteOrderMark("UTF-16BE", 0xFE, 0xFF);
    /** UTF-16LE BOM (Little Endian) */
    public static final ByteOrderMark UTF_16LE = new ByteOrderMark("UTF-16LE", 0xFF, 0xFE);

    private final String charsetName;
    private final int[] bytes;

    /**
     * Construct a new BOM.
     *
     * @param charsetName The name of the charset the BOM represents
     * @param bytes The BOM's bytes
     * @throws IllegalArgumentException if the charsetName is null or
     * zero length
     * @throws IllegalArgumentException if the bytes are null or zero
     * length
     */
    public ByteOrderMark(String charsetName, int... bytes) {
        if (charsetName == null || charsetName.length() == 0) {
            throw new IllegalArgumentException("No charsetName specified");
        }
        if (bytes == null || bytes.length == 0) {
            throw new IllegalArgumentException("No bytes specified");
        }
        this.charsetName = charsetName;
        this.bytes = new int[bytes.length];
        System.arraycopy(bytes, 0, this.bytes, 0, bytes.length);
    }

    /**
     * Return the name of the {@link java.nio.charset.Charset} the BOM represents.
     *
     * @return the character set name
     */
    public String getCharsetName() {
        return charsetName;
    }

    /**
     * Return the length of the BOM's bytes.
     *
     * @return the length of the BOM's bytes
     */
    public int length() {
        return bytes.length;
    }

    /**
     * The byte at the specified position.
     *
     * @param pos The position
     * @return The specified byte
     */
    public int get(int pos) {
        return bytes[pos];
    }

    /**
     * Return a copy of the BOM's bytes.
     *
     * @return a copy of the BOM's bytes
     */
    public byte[] getBytes() {
        byte[] copy = new byte[bytes.length];
        for (int i = 0; i < bytes.length; i++) {
            copy[i] = (byte)bytes[i];
        }
        return copy;
    }

    /**
     * Indicates if this BOM's bytes equals another.
     *
     * @param obj The object to compare to
     * @return true if the bom's bytes are equal, otherwise
     * false
     */
    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof ByteOrderMark)) {
            return false;
        }
        ByteOrderMark bom = (ByteOrderMark)obj;
        if (bytes.length != bom.length()) {
            return false;
        }
        for (int i = 0; i < bytes.length; i++) {
            if (bytes[i] != bom.get(i)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Return the hashcode for this BOM.
     *
     * @return the hashcode for this BOM.
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        int hashCode = getClass().hashCode();
        for (int b : bytes) {
            hashCode += b;
        }
        return hashCode;
    }

    /**
     * Provide a String representation of the BOM.
     *
     * @return the length of the BOM's bytes
     */
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append(getClass().getSimpleName());
        builder.append('[');
        builder.append(charsetName);
        builder.append(": ");
        for (int i = 0; i < bytes.length; i++) {
            if (i > 0) {
                builder.append(",");
            }
            builder.append("0x");
            builder.append(Integer.toHexString(0xFF & bytes[i]).toUpperCase());
        }
        builder.append(']');
        return builder.toString();
    }

}