##How to add validation in android

MainActivity.java

public class FormActivity extends AppCompatActivity {
private EditText mEditText_name, mEditText_email,mEditText_mobile;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_form);
        init_ui();


    }

    private void init_ui() {
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);



        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {
                             addValidation();

                            }
                        }).show();
            }
        });
    }

    private void addValidation() {
        Validation validation = new Validation(this);
        validation.validation_email(R.id.email,"Invalid email Id");
        validation.validation_mobile(R.id.mobile,"Invalid mobile no ");
        validation.validation_name(R.id.name,"Invalid name Id");
    }


}

Validation.java

public class Validation {
    private Activity mActivity;

    public Validation(Activity activity) {
        mActivity = activity;
    }

    public void validation_name(int id, String errorMessage) {


    }

    public void validation_mobile(int id, String errorMessage) {
        EditText editText = (EditText) mActivity.findViewById(id);
        if (!(editText.getText().toString().matches(Patterns.PHONE))) {
            editText.setError(errorMessage);
            return;
        }
    }

    public void validation_email(int id, String errorMessage) {
        EditText editText = (EditText) mActivity.findViewById(id);
        if (!(editText.getText().toString().matches(Patterns.EMAIL_ADDRESS))) {
            editText.setError(errorMessage);
            return;
        }
    }
    

    public class Patterns {
        public static final String EMAIL_ADDRESS = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";
        public static final String PHONE = "[0-9]{10}";
    }

}