用正则表达式判断字符串是不是数字

import java.util.regex.*;

public static  Boolean   IsInt(String   numberString)  
  {  
   Pattern p = Pattern.compile("-*"+"\\d*");        
   Matcher m = p.matcher(numberString);        
   boolean b = m.matches();
   return b;
  }  
public static  Boolean   IsDouble(String   numberString)  
  {  
   Pattern p = Pattern.compile("-*"+"\\d*"+"."+"\\d*");        
   Matcher m = p.matcher(numberString);        
   boolean b = m.matches();
   return b;
  }