001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3.text.translate;
018
019/**
020 * Translates codepoints to their Unicode escaped value suitable for Java source.
021 * 
022 * @since 3.2
023 * @version $Id: JavaUnicodeEscaper.java 1451550 2013-03-01 10:06:13Z olamy $
024 */
025public class JavaUnicodeEscaper extends UnicodeEscaper {
026
027    /**
028     * <p>
029     * Constructs a <code>JavaUnicodeEscaper</code> above the specified value (exclusive).
030     * </p>
031     * 
032     * @param codepoint
033     *            above which to escape
034     * @return the newly created {@code UnicodeEscaper} instance
035     */
036    public static JavaUnicodeEscaper above(final int codepoint) {
037        return outsideOf(0, codepoint);
038    }
039
040    /**
041     * <p>
042     * Constructs a <code>JavaUnicodeEscaper</code> below the specified value (exclusive).
043     * </p>
044     * 
045     * @param codepoint
046     *            below which to escape
047     * @return the newly created {@code UnicodeEscaper} instance
048     */
049    public static JavaUnicodeEscaper below(final int codepoint) {
050        return outsideOf(codepoint, Integer.MAX_VALUE);
051    }
052
053    /**
054     * <p>
055     * Constructs a <code>JavaUnicodeEscaper</code> between the specified values (inclusive).
056     * </p>
057     * 
058     * @param codepointLow
059     *            above which to escape
060     * @param codepointHigh
061     *            below which to escape
062     * @return the newly created {@code UnicodeEscaper} instance
063     */
064    public static JavaUnicodeEscaper between(final int codepointLow, final int codepointHigh) {
065        return new JavaUnicodeEscaper(codepointLow, codepointHigh, true);
066    }
067
068    /**
069     * <p>
070     * Constructs a <code>JavaUnicodeEscaper</code> outside of the specified values (exclusive).
071     * </p>
072     * 
073     * @param codepointLow
074     *            below which to escape
075     * @param codepointHigh
076     *            above which to escape
077     * @return the newly created {@code UnicodeEscaper} instance
078     */
079    public static JavaUnicodeEscaper outsideOf(final int codepointLow, final int codepointHigh) {
080        return new JavaUnicodeEscaper(codepointLow, codepointHigh, false);
081    }
082
083    /**
084     * <p>
085     * Constructs a <code>JavaUnicodeEscaper</code> for the specified range. This is the underlying method for the
086     * other constructors/builders. The <code>below</code> and <code>above</code> boundaries are inclusive when
087     * <code>between</code> is <code>true</code> and exclusive when it is <code>false</code>.
088     * </p>
089     * 
090     * @param below
091     *            int value representing the lowest codepoint boundary
092     * @param above
093     *            int value representing the highest codepoint boundary
094     * @param between
095     *            whether to escape between the boundaries or outside them
096     */
097    public JavaUnicodeEscaper(final int below, final int above, final boolean between) {
098        super(below, above, between);
099    }
100
101    /**
102     * Converts the given codepoint to a hex string of the form {@code "\\uXXXX\\uXXXX"}
103     * 
104     * @param codepoint
105     *            a Unicode code point
106     * @return the hex string for the given codepoint
107     */
108    @Override
109    protected String toUtf16Escape(final int codepoint) {
110        final char[] surrogatePair = Character.toChars(codepoint);
111        return "\\u" + hex(surrogatePair[0]) + "\\u" + hex(surrogatePair[1]);
112    }
113
114}