test java String.matches again

i found the String.matches must match the whole string,could not match part of string

http://stackoverflow.com/questions/4771447/java-string-matches-regex-with-or-pipe

this is a trap

package ZZZZ;

import java.util.regex.PatternSyntaxException;

public class cc {


    public static void main(String[] args) {
       
        String subjectString="我__";
        // TODO Auto-generated method stub
        try {
            String regex="[^a-zA-Z0-9]*$";
           
            boolean foundMatch = subjectString.matches(regex);
            System.out.println(foundMatch);
        } catch (PatternSyntaxException ex) {
            // Syntax error in the regular expression
            System.out.println(ex.toString());
        }

    }

}