java中判斷字符編碼以及轉碼

java中判斷字符編碼以及轉碼
[參考]判斷字符編碼以及轉碼的一個工具類
http://hi.baidu.com/pazhu/blog/item/efcce7a2034ae9a8caefd05b.html
2008-07-01 08:55

/**
* Date: 2008-6-27
* <p>Copyright: Copyright (c) 2006</p>
*
* @version 1.0
* @author: SRH
*/
public class TranCharset {

    private static final String PRE_FIX_UTF = "&#x";
    private static final String POS_FIX_UTF = ";";

    public TranCharset() {
    }

    /**
     * Translate   charset   encoding   to   unicode
     *
     * @param sTemp charset   encoding   is   gb2312
     * @return charset   encoding   is   unicode
     */
    public static String XmlFormalize(String sTemp) {
        StringBuffer sb = new StringBuffer();

        if (sTemp == null || sTemp.equals("")) {
            return "";
        }
        String s = TranCharset.TranEncodeTOGB(sTemp);
        for (int i = 0; i < s.length(); i++) {
            char cChar = s.charAt(i);
            if (TranCharset.isGB2312(cChar)) {
                sb.append(PRE_FIX_UTF);
                sb.append(Integer.toHexString(cChar));
                sb.append(POS_FIX_UTF);
            } else {
                switch ((int) cChar) {
                    case 32:
                        sb.append("&#32;");
                        break;
                    case 34:
                        sb.append("&quot;");
                        break;
                    case 38:
                        sb.append("&amp;");
                        break;
                    case 60:
                        sb.append("&lt;");
                        break;
                    case 62:
                        sb.append("&gt;");
                        break;
                    default:
                        sb.append(cChar);
                }
            }
        }
        return sb.toString();
    }

    /**
     * 將字符串編碼格式轉成GB2312
     *
     * @param str
     * @return
     */
    public static String TranEncodeTOGB(String str) {
        try {
            String strEncode = TranCharset.getEncoding(str);
            String temp = new String(str.getBytes(strEncode), "GB2312");
            return temp;
        } catch (java.io.IOException ex) {

            return null;
        }
    }

    /**
     * 判斷輸入字符是否爲gb2312的編碼格式
     *
     * @param c 輸入字符
     * @return 如果是gb2312返回真，否則返回假
     */
    public static boolean isGB2312(char c) {
        Character ch = new Character(c);
        String sCh = ch.toString();
        try {
            byte[]   bb = sCh.getBytes("gb2312");
            if (bb.length > 1) {
                return true;
            }
        } catch (java.io.UnsupportedEncodingException ex) {
            return false;
        }
        return false;
    }

    /**
     * 判斷字符串的編碼
     *
     * @param str
     * @return
     */
    public static String getEncoding(String str) {
        String encode = "GB2312";
        try {
            if (str.equals(new String(str.getBytes(encode), encode))) {
                String s = encode;
                return s;
            }
        } catch (Exception exception) {
        }
        encode = "ISO-8859-1";
        try {
            if (str.equals(new String(str.getBytes(encode), encode))) {
                String s1 = encode;
                return s1;
            }
        } catch (Exception exception1) {
        }
        encode = "UTF-8";
        try {
            if (str.equals(new String(str.getBytes(encode), encode))) {
                String s2 = encode;
                return s2;
            }
        } catch (Exception exception2) {
        }
        encode = "GBK";
        try {
            if (str.equals(new String(str.getBytes(encode), encode))) {
                String s3 = encode;
                return s3;
            }
        } catch (Exception exception3) {
        }
        return "";
    }
}