Util

 /**
     * Write the context into the given file.
     * 
     * @param context The context.
     * @param theFileName The file name to write to.
     * @throws IOException Exception when create the file.
     */
    public static void writeToFile(String context, String theFileName)
            throws IOException
    {

        if (theFileName != null && !"".equals(theFileName.trim()))
        {
            File aFile = new File(theFileName);
            aFile = new File(aFile.getParent());
            if (!aFile.exists()) {
                aFile.mkdirs();
            }
            BufferedWriter aWriter = new BufferedWriter(new FileWriter(
                    theFileName));
            aWriter.write(context);
            aWriter.close();
        } else
        {
            throw new IllegalArgumentException("Invalid file name!");
        }
    }

 /**
     * get locale
     * @return
     */
    public static Locale getLocale() {
        return new Locale("en", "us");
    }

    /**
     * to String, if object is null, return null, else call it's toString() method
     * @param object
     * @return
     */
    public static String toString(Object object) {
        if (object == null) {
            return null;
        } else {
            return object.toString();
        }
    }

	public static String decPlaceFormater(double value, int length)
	{
		DecimalFormat fmt = new DecimalFormat();
		fmt.setMinimumFractionDigits(length);
		fmt.setMaximumFractionDigits(length);
		return fmt.format(value);
	}

/**
     * Returns true if this string is alpha-numeric; false, otherwise
     * @author liliugen.
     */
    static public boolean isAlphaNumeric(String str) {
        for (int i = 0; i < str.length(); i++) {
            if (!Character.isLetterOrDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }



    /**
     * Returns true if this string is alpha-numeric; false, otherwise
     * @author liliugen.
     */
    static public boolean isDigit(String str) {
        for (int i = 0; i < str.length(); i++) {
            if (!Character.isDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

/**
     * This is a wrapper API to the Base64Encoder 
     * @param input String
     * @return Base64 encoded string
     */
    static public String encodeString(String strInput) {
        Base64Encoder b = new Base64Encoder(strInput);
        return b.processString();
    }

    /**
     * This is a wrapper API to the Base64Decoder 
     * @param input String
     * @return String decoded from Base64 encoded input
     */
    static public String decodeString(String strInput) {
        try {
            Base64Decoder b = new Base64Decoder(strInput);
            return b.processString();
        } catch (Base64FormatException ex) {
            return "";
        }
    }

 /**
     * Returns true if this string is letter only; false, otherwise
     *
     */
    static public boolean isLetters(String str) {
        for (int i = 0; i < str.length(); i++) {
            if (!Character.isLetter(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * Returns true if this string is alpha-numeric; false, otherwise
     * @author Benjamin Yip.
     */
    static public boolean isNumeric(String str) {
        for (int i = 0; i < str.length(); i++) {
            if (!Character.isDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * trim string.
     * using String.trim() to trim string.if string is null, return null
     * @param string
     */
    public static String trim(String string) {
        if (string == null) {
            return string;
        } else {
            return string.trim();
        }
    }

    /**
     * trim string, if input is null, return "";
     * @param string
     */
    public static String trimNoNull(String string) {
        if (string == null) {
            return "";
        } else {
            return string.trim();
        }
    }