Commons项目中用来处理常用的编码方法的工具类包，例如DES、SHA1、MD5、Base64, 及 hex, metaphone, soundex 等编码演算。

JavaDoc:http://www.osctools.net/apidocs/apidoc?api=commons-codec

官网下载地址：http://commons.apache.org/codec/

使用：

A.Base64 编解码

package demo;import org.apache.commons.codec.binary.Base64;public class Base64Test {public static void main(String[] args) {Base64 base64 = new Base64();String str = "中文";byte[] enbytes = null;String encodeStr = null;byte[] debytes = null;String decodeStr = null;enbytes = base64.encode(str.getBytes());encodeStr = new String(enbytes);debytes = base64.decode(enbytes);decodeStr = new String(debytes);System.out.println("编码前:" + str);System.out.println("编码后:" + encodeStr);System.out.println("解码后:" + decodeStr);}
}

B.Hex 编解码

package demo;import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;public class HexTest {public static void main(String[] args) throws DecoderException {Hex hex = new Hex();String str = "中文";char[] enbytes = null;String encodeStr = null;byte[] debytes = null;String decodeStr = null;enbytes = hex.encodeHex(str.getBytes());encodeStr = new String(enbytes);debytes = hex.decodeHex(enbytes);decodeStr = new String(debytes);System.out.println("编码前:" + str);System.out.println("编码后:" + encodeStr);System.out.println("解码后:" + decodeStr);}
}

C.Metaphone 及 Soundex 编码

package demo;import org.apache.commons.codec.language.Metaphone;
import org.apache.commons.codec.language.RefinedSoundex;
import org.apache.commons.codec.language.Soundex;public class LanguageTest {public static void main(String[] args) {Metaphone metaphone = new Metaphone();RefinedSoundex refinedSoundex = new RefinedSoundex();Soundex soundex = new Soundex();for (int i = 0; i < 2; i++) {String str = (i == 0) ? "resume" : "resin";String mString = null;String rString = null;String sString = null;try {mString = metaphone.encode(str);rString = refinedSoundex.encode(str);sString = soundex.encode(str);} catch (Exception ex) {;}System.out.println("Original:" + str);System.out.println("Metaphone:" + mString);System.out.println("RefinedSoundex:" + rString);System.out.println("Soundex:" + sString + "\n");}}
}

Metaphone 建立出相同的key给发音相似的单字, 比 Soundex 还要准确, 但是 Metaphone 没有固定长度, Soundex 则是固定第一个英文字加上3个数字. 这通常是用在类似音比对, 也可以用在 MP3 的软件开发.