Checks if a String is empty ("") or null. : String Match « Data Type « Java Tutorial






  1. Java Tutorial
  2. Data Type
  3. String Match
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.TimeZone;


/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */




/**
 * Operations on {@link java.lang.String} that are
 * <code>null</code> safe.

 *
 * @see java.lang.String
 * @author <a href="http://jakarta.apache.org/turbine/">Apache Jakarta Turbine</a>
 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
 * @author Daniel L. Rall
 * @author <a href="mailto:gcoladonato@yahoo.com">Greg Coladonato</a>
 * @author <a href="mailto:ed@apache.org">Ed Korthof</a>
 * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
 * @author Stephen Colebourne
 * @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a>
 * @author Holger Krauth
 * @author <a href="mailto:alex@purpletech.com">Alexander Day Chaffee</a>
 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
 * @author Arun Mammen Thomas
 * @author Gary Gregory
 * @author Phil Steitz
 * @author Al Chou
 * @author Michael Davey
 * @author Reuben Sivan
 * @author Chris Hyzer
 * @author Scott Johnson
 * @since 1.0
 * @version $Id: StringUtils.java 635447 2008-03-10 06:27:09Z bayard $
 */
public class Main {

  // Empty checks
  //-----------------------------------------------------------------------
  /**
   * Checks if a String is empty ("") or null.
   *
   * <pre>
   * StringUtils.isEmpty(null)      = true
   * StringUtils.isEmpty("")        = true
   * StringUtils.isEmpty(" ")       = false
   * StringUtils.isEmpty("bob")     = false
   * StringUtils.isEmpty("  bob  ") = false
   * </pre>
   *
   * NOTE: This method changed in Lang version 2.0.
   * It no longer trims the String.
   * That functionality is available in isBlank().
   *
   * @param str  the String to check, may be null
   * @return <code>true</code> if the String is empty or null
   */
  public static boolean isEmpty(String str) {
      return str == null || str.length() == 0;
  }
}








2.31.String Match
2.31.1.Match Phone Number
2.31.2.Match Zip Codes
2.31.3.Match Dates
2.31.4.Match Name Formats
2.31.5.Case insensitive check if a String ends with a specified suffix.
2.31.6.Case insensitive check if a String starts with a specified prefix.
2.31.7.Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.
2.31.8.Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
2.31.9.Check if a String ends with a specified suffix.
2.31.10.Check if a String starts with a specified prefix.
2.31.11.Check if a string is present at the current position in another string.
2.31.12.Check whether the given String is a valid identifier according to the Java Language specifications.
2.31.13.Checks if String contains a search String irrespective of case, handling null
2.31.14.Checks if String contains a search String, handling null
2.31.15.Checks if String contains a search character, handling null
2.31.16.Checks if a String is empty ("") or null.
2.31.17.Checks if a String is not empty ("") and not null.
2.31.18.Checks if a String is whitespace, empty ("") or null.
2.31.19.Checks if the String contains any character in the given set of characters.
2.31.20.Checks if the String contains only certain characters.