常用验证方法

1.正则表达式

 

      /**

       * 判断字符串是否为纯数字格式

       * @param num

       * @return

       * @throws BizException

       */

      public static boolean verifyNum(String num) throws BizException {

             if (num != null && !num.trim().equals( "")) {

                  Pattern p = Pattern. compile("^[0-9]*$");

                  Matcher m = p.matcher(num);

                   boolean b = m.matches();

                   if (b) {

                         return true;

                  }

            }

             return false;

      }

      

      /**

       * 判断字符串是否为纯字母格式

       * @param num

       * @return

       * @throws BizException

       */

      public static boolean verifyLetter(String str) throws BizException {

             if (str != null && !str.trim().equals( "")) {

                  Pattern p = Pattern. compile("^[A-Za-z]+$");

                  Matcher m = p.matcher(str);

                   boolean b = m.matches();

                   if (b) {

                         return true;

                  }

            }

             return false;

      }

      

      /**

       * 判断字符串是否为纯字母和数字格式

       * @param num

       * @return

       * @throws BizException

       */

      public static boolean verifyLetterAndNum(String str) throws BizException {

             if (str != null && !str.trim().equals( "")) {

                  Pattern p = Pattern. compile("^[A-Za-z0-9]+$");

                  Matcher m = p.matcher(str);

                   boolean b = m.matches();

                   if (b) {

                         return true;

                  }

            }

             return false;

      }

 

2.判断字符串是否包含汉字

public class Test {

 

      public static void main(String[] args) {

            // 方法一：

           String s1 = "我是中国人" ;

           String s2 = "imchinese" ;

           String s3 = "im中国人" ;

            System. out.println(s1 + ":" + new String(s1).length());

            System. out.println(s2 + ":" + new String(s2).length());

            System. out.println(s3 + ":" + new String(s3).length());

            System. out.println((s1.getBytes(). length == s1.length()) ? "s1无汉字"

                     : "s1有汉字" );

            System. out.println((s2.getBytes(). length == s2.length()) ? "s2无汉字"

                     : "s2有汉字" );

            System. out.println((s3.getBytes(). length == s3.length()) ? "s3无汉字"

                     : "s3有汉字" );

 

            // 方法二：

            int count = 0;

           String regEx = "[\\u4e00-\\u9fa5]" ;

           String str = "中文fd我是中国人as " ;

           Pattern p = Pattern. compile(regEx);

           Matcher m = p.matcher(str);

            while (m.find()) {

                 for ( int i = 0; i <= m.groupCount(); i++) {

                     count = count + 1;

                }

           }

            System. out.println( "共有 " + count + "个 " );

     }

}