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 }