How to validate Text field in java.It should accept only numric value.

[Ravi Sinha]

Hi There!
I shall be thankfull if u will help me out writing method where it should validate text field(in java).It should accept only numric value.
These are following criteria:
The number is between 1 and 12 digits in length
The number is all digits (i.e. contains no alpha characters)
The number is not all zeros
If the number is 7 or more digits in length then
--The number cannot be all the same digit
--The number cannot be a sequence where zero is in sequence with both 1 and 9.

waiting for reply.

[Manish Hatwalne]

Have a look at JFormattedTextField, it does have some nice exmplaes of validation formats as well.

HTH,
- Manish

[Damanjit Kaur]

Hi

Here is an example for that.

public void test()
{
TextField t = new TextField(29);

String s="134a897";
if((s.length() > 0) && (s.length() < 13))
{
System.out.println("inside first loop");

for(int i=0;i<s.length();i++) // check for all digits
{
switch(s.charAt(i))
{
case '0' : break;
case '1' : break;
case '2' : break;
case '3' : break;
case '4' : break;
case '5' : break;
case '6' : break;
case '7' : break;
case '8' : break;
case '9' : break;
default : throw new RuntimeException("Not all digits");
}

}
if(s.length() >= 7) // check for total digits more than 7
{
int i=0;
for(;s.charAt(i) == s.charAt(i+1);i++) // check for all digits same
{
if(i >= (s.length()-2))
break;
}
System.out.println("outside i "+i+" "+s.length());
if(i==s.length()-2){
System.out.println("inside i "+i+" "+s.length());
throw new RuntimeException("Number with same digits"); }

int c=0;
i=s.indexOf('1',c);

while((i != -1) && (c <=6) )
{
System.out.println("inside while "+i+ "c "+c);
if(s.charAt(c+1)=='0')
{
throw new RuntimeException("Number with sequence as 10");
}
i=s.indexOf('1',c++);
}

i=c=0;
i=s.indexOf('9',c);
while((i != -1) && (c <=6))
{
if(s.charAt(i+1)=='0')
{
throw new RuntimeException("Number with sequence as 90");
}
i=s.indexOf('9',c++);
}

}
}
}

[sasi kala]

FileName: CheckDigits.java

 
import java.util.regex.*;
 
class CheckDigits
{
    [B]// Method which checks for sequence of 0000000 or 111111 etc.,[/B]
    public static int numberOfMatches(String str,String find)
    {
        int count = 0;
        for(int i=0;i<str.length();i++)
         if(str.substring(i,i+1).equals(find))
                      count++;
        return count;
    }
 
    public static void main (String args[])
    {
        String str = "7777772777";
        boolean flag = true;
 
 [B]//This if condition checks for
    // given string length is 1 to 12 or not
    // and all characters are digits or not -- Pattern.matches("^\\d*",str)
    // and all characters should not be 0's eg., 0000000000  
    [/B]
 
        if(str.length()>0 && str.length()<=12 && Pattern.matches("^\\d*",str) && str.length()!=numberOfMatches(str,"0"))
        {
           if(str.length()>=7)  [B] //string length > 7[/B]
           {
         [B]//Rules are 1.should not have sequence of same digits 88888888
                        2.should not contain 09 or 90 or 10 or 10 [/B]
 
               [B]This below if is for Rule.1[/B] 
               if(str.length()!=numberOfMatches(str,str.substring(0,1)))
               {
                 [B]This below if for Rule.2[/B] 
                  if(Pattern.matches("^\\d*[09||90||10||01]\\d*",str))
                    flag = false;
               }
               else
                    flag = false;
           }
        }
        else
            flag = false;
 
        if(flag)
            System.out.println("ok");
        else
            System.out.println("not ok");
    }
} 

Hope This Helps.
All The Best