在实际的应用中，我们经常需要对字符串进行编解码，Apache Commons家族中的Commons Codec就提供了一些公共的编解码实现，比如Base64, Hex, MD5,Phonetic and URLs等等。
一、官方网址：
http://commons.apache.org/codec/
二、例子
1、 Base64编解码
private static String encodeTest(String str){
Base64 base64 = new Base64();
try {
str = base64.encodeToString(str.getBytes(“UTF-8”));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
System.out.println(“Base64 编码后：”+str);
return str;
}
private static void decodeTest(String str){
Base64 base64 = new Base64();
//str = Arrays.toString(Base64.decodeBase64(str));
str = new String(Base64.decodeBase64(str));
System.out.println(“Base64 解码后：”+str);
}
2、 Hex编解码
private static String encodeHexTest(String str){
try {
str = Hex.encodeHexString(str.getBytes(“UTF-8”));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
System.out.println(“Hex 编码后：”+str);
return str;
}
private static String decodeHexTest(String str){
Hex hex = new Hex();
try {
str = new String((byte[])hex.decode(str));
} catch (DecoderException e) {
e.printStackTrace();
}
System.out.println(“Hex 编码后：”+str);
return str;
}
3、 MD5加密
private static String MD5Test(String str){
try {
System.out.println(“MD5 编码后：”+newString(DigestUtils.md5Hex(str.getBytes(“UTF-8”))));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return str;
}
4、 SHA编码
private static String ShaTest(String str){
try {
System.out.println(“SHA 编码后：”+newString(DigestUtils.shaHex(str.getBytes(“UTF-8”))));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return str;
}
5、 Metaphone和Soundex
这个例子来源于网上，网址见：
http://350129923.blog.163.com/blog/static/17959113200763144659125/
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.
import org.apache.commons.codec.language.*;
import org.apache.commons.codec.*;
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”);
}
}
}