Apache Commons Lang 3 is the 3rd version of Apache Commons Lang, which provides a host of helper utilities for the java.lang API.

Apache Commons Lang 3 Source Code files are provided in both binary packge (commons-lang3-3.12.0-bin.zip) and source package (commons-lang3-3.12.0-src.zip). You can download them at Apache Commons Lang Website.

Apache Commons Lang 3 Source Code has no dependencies and is compatible with Java 8 and newer versions. You can compile it to generate your own version of Apache Commons Lang 3 JAR file.

You can also browse the source code below:

⏎ org/apache/commons/lang3/text/translate/UnicodeUnescaper.java

/*
 * 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.lang3.text.translate;

import java.io.IOException;
import java.io.Writer;

/**
 * Translates escaped Unicode values of the form \\u+\d\d\d\d back to
 * Unicode. It supports multiple 'u' characters and will work with or
 * without the +.
 *
 * @since 3.0
 * @deprecated as of 3.6, use commons-text
 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/UnicodeUnescaper.html">
 * UnicodeUnescaper</a> instead
 */
@Deprecated
public class UnicodeUnescaper extends CharSequenceTranslator {

    /**
     * {@inheritDoc}
     */
    @Override
    public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
        if (input.charAt(index) == '\\' && index + 1 < input.length() && input.charAt(index + 1) == 'u') {
            // consume optional additional 'u' chars
            int i = 2;
            while (index + i < input.length() && input.charAt(index + i) == 'u') {
                i++;
            }

            if (index + i < input.length() && input.charAt(index + i) == '+') {
                i++;
            }

            if (index + i + 4 <= input.length()) {
                // Get 4 hex digits
                final CharSequence unicode = input.subSequence(index + i, index + i + 4);

                try {
                    final int value = Integer.parseInt(unicode.toString(), 16);
                    out.write((char) value);
                } catch (final NumberFormatException nfe) {
                    throw new IllegalArgumentException("Unable to parse unicode value: " + unicode, nfe);
                }
                return i + 4;
            }
            throw new IllegalArgumentException("Less than 4 hex digits in unicode value: '" + input.subSequence(index, input.length())
                    + "' due to end of CharSequence");
        }
        return 0;
    }
}

⏎ org/apache/commons/lang3/text/translate/UnicodeUnescaper.java

Or download all of them as a single archive file:

File name: commons-lang3-3.12.0-sources.jar
File size: 651724 bytes
Release date: 2020-01-22
Download 

⇒ Download and Install commons-lang3-3.8.1-bin.zip

⇐ Download Apache Commons Lang v3 Source Package

⇑ Downloading and Reviewing commons-lang.jar

⇑⇑ FAQ for Apache commons-lang.jar