工具类：全角半角相互转换

/**
     * 半角转全角
     * @param input String.
     * @return 全角字符串.
     */
    public static String ToSBC(String input) {
             char c[] = input.toCharArray();
             for (int i = 0; i < c.length; i++) {
               if (c[i] == ‘ ‘) {
                 c[i] = ‘\u3000‘;
               } else if (c[i] < ‘\177‘) {
                 c[i] = (char) (c[i] + 65248);
               }
             }
             return new String(c);
    }
    /**
     * 全角转半角
     * @param input String.
     * @return 半角字符串
     */
    public static String ToDBC(String input) {        
             char c[] = input.toCharArray();
             for (int i = 0; i < c.length; i++) {
               if (c[i] == ‘\u3000‘) {
                 c[i] = ‘ ‘;
               } else if (c[i] > ‘\uFF00‘ && c[i] < ‘\uFF5F‘) {
                 c[i] = (char) (c[i] - 65248);
               }
             }
        String returnString = new String(c);
             return returnString;
    } 

工具类：全角半角相互转换

原文：http://my.oschina.net/sldk/blog/403405