Does Android have a function to validate passwords

问题:

I'm developing an Android app and one of my tasks is to check the strength of a password.

Are there any built-in functions for checking the strength of a password?

回答1:

In order to answer the question, there is no Android function to do this, the closest and best way is to use regex as Mkyong suggested on his blog:

private Pattern pattern;
      private Matcher matcher;

      private static final String PASSWORD_PATTERN = 
              "((?=.*\\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20})";

      public PasswordValidator(){
          pattern = Pattern.compile(PASSWORD_PATTERN);
      }

      /**
       * Validate password with regular expression
       * @param password password for validation
       * @return true valid password, false invalid password
       */
      public boolean validate(final String password){

          matcher = pattern.matcher(password);
          return matcher.matches();

      }

回答2:

If you dont't want to use external libs.. you can check it yourself.. Something like this:

   public void onSubmitClicked(View v) 
    { 
        String pass = passwordEditText.getText().toString(); 
        if(TextUtils.isEmpty(pass) || pass.length < [YOUR MIN LENGTH]) 
        { 
            passwordEditText.setError("You must more characters in your password"); 
            return; 
        }
        if(....){
              // do other controls here
        }


    }

回答3:

Sounds like you need an external library such as http://code.google.com/p/vt-middleware/wiki/vtpassword etc.

Or it is simple enough to code up something like checking how long it is, what characters it has etc and printing out different things based on that.

If say a user had a 10 length password and some upper case characters you could increment some password strength parameter based on this, rewarding more complex passwords. You can set teh thresholds yourself.