    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     */
    017    package org.apache.commons.lang3.text.translate;
    018
    019    import java.io.IOException;
    020    import java.io.Writer;
    021
    022    /**
    023     * Translates codepoints to their unicode escaped value.
    024     *
    025     * @author Apache Software Foundation
    026     * @since 3.0
    027     * @version $Id: UnicodeEscaper.java 967237 2010-07-23 20:08:57Z mbenson $
    028     */
    029    public class UnicodeEscaper extends CodePointTranslator {
    030
    031        private final int below;
    032        private final int above;
    033        private final boolean between;
    034
    035        public UnicodeEscaper(){
    036            this(0, Integer.MAX_VALUE, true);
    037        }
    038
    039        private UnicodeEscaper(int below, int above, boolean between) {
    040            this.below = below;
    041            this.above = above;
    042            this.between = between;
    043        }
    044
    045        public static UnicodeEscaper below(int codepoint) {
    046            return outsideOf(codepoint, Integer.MAX_VALUE);
    047        }
    048
    049        public static UnicodeEscaper above(int codepoint) {
    050            return outsideOf(0, codepoint);
    051        }
    052
    053        public static UnicodeEscaper outsideOf(int codepointLow, int codepointHigh) {
    054            UnicodeEscaper escaper = new UnicodeEscaper(codepointLow, codepointHigh, false);
    055            return escaper;
    056        }
    057
    058        public static UnicodeEscaper between(int codepointLow, int codepointHigh) {
    059            UnicodeEscaper escaper = new UnicodeEscaper(codepointLow, codepointHigh, true);
    060            return escaper;
    061        }
    062
    063        /**
    064         * {@inheritDoc}
    065         */
    066        @Override
    067        public boolean translate(int codepoint, Writer out) throws IOException {
    068            if(between) {
    069                if (codepoint < below || codepoint > above) {
    070                    return false;
    071                }
    072            } else {
    073                if (codepoint >= below && codepoint <= above) {
    074                    return false;
    075                }
    076            }
    077
    078            // TODO: Handle potential + sign per various unicode escape implementations
    079            if (codepoint > 0xffff) {
    080                // TODO: Figure out what to do. Output as two unicodes?
    081                //       Does this make this a Java-specific output class?
    082                out.write("\\u" + hex(codepoint));
    083            } else if (codepoint > 0xfff) {
    084                out.write("\\u" + hex(codepoint));
    085            } else if (codepoint > 0xff) {
    086                out.write("\\u0" + hex(codepoint));
    087            } else if (codepoint > 0xf) {
    088                out.write("\\u00" + hex(codepoint));
    089            } else {
    090                out.write("\\u000" + hex(codepoint));
    091            }
    092            return true;
    093        }
    094    }