[轉發] java字符串-編碼轉換-工具類

copy來的，原地址：http://-w-w-w-.-z-u-i-d-a-i-m-a-.-c-o-m-/share/1795356301560832.htm

import java.io.UnsupportedEncodingException;
 
/**
 * 轉換字符串的編碼
 */
public class ChangeCharset {
    /** 7位ASCII字符，也叫做ISO646-US、Unicode字符集的基本拉丁塊 */
    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 轉換格式 */
    public static final String UTF_8 = "UTF-8";
 
    /** 16 位 UCS 轉換格式，Big Endian（最低地址存放高位字節）字節順序 */
    public static final String UTF_16BE = "UTF-16BE";
 
    /** 16 位 UCS 轉換格式，Little-endian（最高地址存放低位字節）字節順序 */
    public static final String UTF_16LE = "UTF-16LE";
 
    /** 16 位 UCS 轉換格式，字節順序由可選的字節順序標記來標識 */
    public static final String UTF_16 = "UTF-16";
 
    /** 中文超大字符集 */
    public static final String GBK = "GBK";
 
    /**
     * 將字符編碼轉換成US-ASCII碼
     */
    public String toASCII(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, US_ASCII);
    }
 
    /**
     * 將字符編碼轉換成ISO-8859-1碼
     */
    public String toISO_8859_1(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, ISO_8859_1);
    }
 
    /**
     * 將字符編碼轉換成UTF-8碼
     */
    public String toUTF_8(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, UTF_8);
    }
 
    /**
     * 將字符編碼轉換成UTF-16BE碼
     */
    public String toUTF_16BE(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, UTF_16BE);
    }
 
    /**
     * 將字符編碼轉換成UTF-16LE碼
     */
    public String toUTF_16LE(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, UTF_16LE);
    }
 
    /**
     * 將字符編碼轉換成UTF-16碼
     */
    public String toUTF_16(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, UTF_16);
    }
 
    /**
     * 將字符編碼轉換成GBK碼
     */
    public String toGBK(String str) throws UnsupportedEncodingException {
        return this.changeCharset(str, GBK);
    }
 
    /**
     * 字符串編碼轉換的實現方法
     * 
     * @param str
     *            待轉換編碼的字符串
     * @param newCharset
     *            目標編碼
     * @return
     * @throws UnsupportedEncodingException
     */
    public String changeCharset(String str, String newCharset)
            throws UnsupportedEncodingException {
        if (str != null) {
            // 用默認字符編碼解碼字符串。
            byte[] bs = str.getBytes();
            // 用新的字符編碼生成字符串
            return new String(bs, newCharset);
        }
        return null;
    }
 
    /**
     * 字符串編碼轉換的實現方法
     * 
     * @param str
     *            待轉換編碼的字符串
     * @param oldCharset
     *            原編碼
     * @param newCharset
     *            目標編碼
     * @return
     * @throws UnsupportedEncodingException
     */
    public String changeCharset(String str, String oldCharset, String newCharset)
            throws UnsupportedEncodingException {
        if (str != null) {
            // 用舊的字符編碼解碼字符串。解碼可能會出現異常。
            byte[] bs = str.getBytes(oldCharset);
            // 用新的字符編碼生成字符串
            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("轉換成GBK碼: " + gbk);
        System.out.println();
        String ascii = test.toASCII(str);
        System.out.println("轉換成US-ASCII碼: " + ascii);
        gbk = test.changeCharset(ascii, ChangeCharset.US_ASCII,
                ChangeCharset.GBK);
        System.out.println("再把ASCII碼的字符串轉換成GBK碼: " + gbk);
        System.out.println();
        String iso88591 = test.toISO_8859_1(str);
        System.out.println("轉換成ISO-8859-1碼: " + iso88591);
        gbk = test.changeCharset(iso88591, ChangeCharset.ISO_8859_1,
                ChangeCharset.GBK);
        System.out.println("再把ISO-8859-1碼的字符串轉換成GBK碼: " + gbk);
        System.out.println();
        String utf8 = test.toUTF_8(str);
        System.out.println("轉換成UTF-8碼: " + utf8);
        gbk = test.changeCharset(utf8, ChangeCharset.UTF_8, ChangeCharset.GBK);
        System.out.println("再把UTF-8碼的字符串轉換成GBK碼: " + gbk);
        System.out.println();
        String utf16be = test.toUTF_16BE(str);
        System.out.println("轉換成UTF-16BE碼:" + utf16be);
        gbk = test.changeCharset(utf16be, ChangeCharset.UTF_16BE,
                ChangeCharset.GBK);
        System.out.println("再把UTF-16BE碼的字符串轉換成GBK碼: " + gbk);
        System.out.println();
        String utf16le = test.toUTF_16LE(str);
        System.out.println("轉換成UTF-16LE碼:" + utf16le);
        gbk = test.changeCharset(utf16le, ChangeCharset.UTF_16LE,
                ChangeCharset.GBK);
        System.out.println("再把UTF-16LE碼的字符串轉換成GBK碼: " + gbk);
        System.out.println();
        String utf16 = test.toUTF_16(str);
        System.out.println("轉換成UTF-16碼:" + utf16);
        gbk = test.changeCharset(utf16, ChangeCharset.UTF_16LE,
                ChangeCharset.GBK);
        System.out.println("再把UTF-16碼的字符串轉換成GBK碼: " + gbk);
        String s = new String("中文".getBytes("UTF-8"), "UTF-8");
        System.out.println(s);
    }
}