Java tutorial
//package com.java2s; /* * Copyright 2011 CodeFlux, Inc <info@teamcodeflux.com> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import android.widget.TextView; import java.util.concurrent.Callable; public class Main { public static Callable<Boolean> notBlank(final TextView view) { return new Callable<Boolean>() { @Override public Boolean call() throws Exception { if (view == null || view.getText() == null) { throw new IllegalArgumentException("TextView should not be null!"); } return view.getText().length() > 0; } }; } }