字符串编码转换

package com.shanli.jxmastomodem.util;  
 
import java.io.UnsupportedEncodingException;  
 
/** 
 * 转换字符串的编码 
 * @author aone 
 */ 
 
public class ChangeCharset {  
 
    /** 7位ASCII字符，也叫作ISO646-US、Unicode字符集的基本拉丁块 */ 
    public static final String US_ASCII = "US-ASCII";  
      
    /** ISO拉丁字母表 No.1，也叫做ISO-LATIN-1 */ 
    public static final String ISO_8859_1 = "ISO-8859-1";  
      
    /** 8 位 UCS 转换格式 */ 
    public static final String UTF_8 = "UTF-8";  
      
    /** 16 位 UCS 转换格式，Big Endian(最低地址存放高位字节）字节顺序 */ 
    public static final String UTF_16BE = "UTF-16BE";  
      
    /** 16 位 UCS 转换格式，Litter Endian（最高地址存放地位字节）字节顺序 */ 
    public static final String UTF_16LE = "UTF-16LE";  
      
    /** 16 位 UCS 转换格式，字节顺序由可选的字节顺序标记来标识 */ 
    public static final String UTF_16 = "UTF-16";  
      
    /** 中文超大字符集 **/ 
    public static final String GBK = "GBK";  
 
    public static final String GB2312 = "GB2312";  
 
    /** 将字符编码转换成US-ASCII码 */ 
    public String toASCII(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, US_ASCII);  
    }  
 
    /** 将字符编码转换成ISO-8859-1 */ 
    public String toISO_8859_1(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, ISO_8859_1);  
    }  
 
    /** 将字符编码转换成UTF-8 */ 
    public String toUTF_8(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, UTF_8);  
    }  
 
    /** 将字符编码转换成UTF-16BE */ 
    public String toUTF_16BE(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, UTF_16BE);  
    }  
 
    /** 将字符编码转换成UTF-16LE */ 
    public String toUTF_16LE(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, UTF_16LE);  
    }  
 
    /** 将字符编码转换成UTF-16 */ 
    public String toUTF_16(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, UTF_16);  
    }  
 
    /** 将字符编码转换成GBK */ 
    public String toGBK(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, GBK);  
    }  
 
    /** 将字符编码转换成GB2312 */ 
    public String toGB2312(String str) throws UnsupportedEncodingException {  
        return this.changeCharset(str, GB2312);  
    }  
 
    /** 
     * 字符串编码转换的实现方法 
     * @param str 待转换的字符串 
     * @param newCharset  目标编码 
     */ 
    public String changeCharset(String str, String newCharset)  
            throws UnsupportedEncodingException {  
        if (str != null) {  
            // 用默认字符编码解码字符串。与系统相关，中文windows默认为GB2312  
            byte[] bs = str.getBytes();  
            return new String(bs, newCharset); // 用新的字符编码生成字符串  
        }  
        return null;  
    }  
 
    /** 
     * 字符串编码转换的实现方法 
     * @param str 待转换的字符串 
     * @param oldCharset  源字符集 
     * @param newCharset 目标字符集 
     */ 
    public String changeCharset(String str, String oldCharset, String newCharset)  
            throws UnsupportedEncodingException {  
        if (str != null) {  
            // 用源字符编码解码字符串  
            byte[] bs = str.getBytes(oldCharset);  
            return new String(bs, newCharset);  
        }  
        return null;  
    }  
 
    public static void main(String[] args) throws UnsupportedEncodingException {  
        ChangeCharset test = new ChangeCharset();  
        String str = "This is a 中文的 String!";  
        System.out.println("str：" + str);  
 
        String gbk = test.toGBK(str);  
        System.out.println("转换成GBK码：" + gbk);  
        System.out.println();  
 
        String ascii = test.toASCII(str);  
        System.out.println("转换成US-ASCII：" + ascii);  
        System.out.println();  
 
        String iso88591 = test.toISO_8859_1(str);  
        System.out.println("转换成ISO-8859-1码：" + iso88591);  
        System.out.println();  
 
        gbk = test.changeCharset(iso88591, ISO_8859_1, GBK);  
        System.out.println("再把ISO-8859-1码的字符串转换成GBK码：" + gbk);  
        System.out.println();  
 
        String utf8 = test.toUTF_8(str);  
        System.out.println();  
        System.out.println("转换成UTF-8码：" + utf8);  
        String utf16be = test.toUTF_16BE(str);  
        System.out.println("转换成UTF-16BE码：" + utf16be);  
        gbk = test.changeCharset(utf16be, UTF_16BE, GBK);  
        System.out.println("再把UTF-16BE编码的字符转换成GBK码：" + gbk);  
        System.out.println();  
 
        String utf16le = test.toUTF_16LE(str);  
        System.out.println("转换成UTF-16LE码：" + utf16le);  
        gbk = test.changeCharset(utf16le, UTF_16LE, GBK);  
        System.out.println("再把UTF-16LE编码的字符串转换成GBK码：" + gbk);  
        System.out.println();  
 
        String utf16 = test.toUTF_16(str);  
        System.out.println("转换成UTF-16码：" + utf16);  
        String gb2312 = test.changeCharset(utf16, UTF_16, GB2312);  
        System.out.println("再把UTF-16编码的字符串转换成GB2312码：" + gb2312);  
    }  
 
}