Apache Commons Codec library provides implementations of common encoders and decoders such as Base64, Hex, Phonetic and URLs.

Apache Commons Codec Source Code files are provided in both binary packge (commons-codec-3.15-bin.zip) and source package (commons-codec-3.15-src.zip). You can download them at Apache Commons Codec Website.

Apache Commons Codec Source Code has no dependencies. You can compile it to generate your own version of Apache Commons Codec JAR file.

The source code of Apache Commons Codec 1.15 is provided below:

⏎ org/apache/commons/codec/StringDecoder.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.codec;

/**
 * Defines common decoding methods for String decoders.
 *
 */
public interface StringDecoder extends Decoder {

    /**
     * Decodes a String and returns a String.
     *
     * @param source
     *            the String to decode
     * @return the encoded String
     * @throws DecoderException
     *             thrown if there is an error condition during the Encoding process.
     */
    String decode(String source) throws DecoderException;
}

⏎ org/apache/commons/codec/StringDecoder.java

Or download all of them as a single archive file:

File name: commons-codec-1.15-sources.jar
File size: 364441 bytes
Release date: 2020-09-01
Download 

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