Check if a String starts with any of an array of specified strings - Java java.lang

Java examples for java.lang:String Start

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Description

Check if a String starts with any of an array of specified strings

Demo Code

/*/*from  w w w  .  j a v  a 2 s . c o  m*/
 * Copyright 2013 Guidewire Software, Inc.
 */
/**
 * This class is based, in part, on org.apache.commons.lang.StringUtils and is intended
 * to break the dependency on that project.
 *
 * @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
 *  Johnson

 */
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Collection;
import java.util.ArrayList;
import java.util.Formatter;
import java.util.List;
import java.util.Iterator;
import java.util.Locale;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class Main{
    public static void main(String[] argv){
        String string = "java2s.com";
        String[] searchStrings = new String[]{"1","abc","level",null,"java2s.com","asdf 123"};
        System.out.println(startsWithAny(string,searchStrings));
    }
    /**
     * <p>Check if a String starts with any of an array of specified strings.</p>
     *
     * <pre>
     * startsWithAny(null, null)      = false
     * startsWithAny(null, new String[] {"abc"})  = false
     * startsWithAny("abcxyz", null)     = false
     * startsWithAny("abcxyz", new String[] {""}) = false
     * startsWithAny("abcxyz", new String[] {"abc"}) = true
     * startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
     * </pre>
     *
     * @param string  the String to check, may be null
     * @param searchStrings the Strings to find, may be null or empty
     * @return <code>true</code> if the String starts with any of the the prefixes, case insensitive, or
     *  both <code>null</code>
     * @since 3.0
     */
    public static boolean startsWithAny(String string,
            String[] searchStrings) {
        if (isEmpty(string) || searchStrings == null) {
            return false;
        }
        for (int i = 0; i < searchStrings.length; i++) {
            String searchString = searchStrings[i];
            if (startsWith(string, searchString)) {
                return true;
            }
        }
        return false;
    }
    /**
     * <p>Checks if a String is empty ("") or null.</p>
     *
     * <pre>
     * StringUtils.isEmpty(null)      = true
     * StringUtils.isEmpty("")        = true
     * StringUtils.isEmpty(" ")       = false
     * StringUtils.isEmpty("bob")     = false
     * StringUtils.isEmpty("  bob  ") = false
     * </pre>
     *
     * <p>NOTE: This method changed in Lang version 2.0.
     * It no longer trims the String.
     * That functionality is available in isBlank().</p>
     *
     * @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;
    }
    /**
     * <p>Check if a String starts with a specified prefix.</p>
     *
     * <p><code>null</code>s are handled without exceptions. Two <code>null</code>
     * references are considered to be equal. The comparison is case sensitive.</p>
     *
     * <pre>
     * startsWith(null, null)      = true
     * startsWith(null, "abc")     = false
     * startsWith("abcdef", null)  = false
     * startsWith("abcdef", "abc") = true
     * startsWith("ABCDEF", "abc") = false
     * </pre>
     *
     * @see java.lang.String#startsWith(String)
     * @param str  the String to check, may be null
     * @param prefix the prefix to find, may be null
     * @return <code>true</code> if the String starts with the prefix, case sensitive, or
     *  both <code>null</code>
     * @since 2.4
     */
    public static boolean startsWith(String str, String prefix) {
        return startsWith(str, prefix, false);
    }
    /**
     * <p>Check if a String starts with a specified prefix (optionally case insensitive).</p>
     *
     * @see java.lang.String#startsWith(String)
     * @param str  the String to check, may be null
     * @param prefix the prefix to find, may be null
     * @param ignoreCase inidicates whether the compare should ignore case
     *  (case insensitive) or not.
     * @return <code>true</code> if the String starts with the prefix or
     *  both <code>null</code>
     */
    private static boolean startsWith(String str, String prefix,
            boolean ignoreCase) {
        if (str == null || prefix == null) {
            return (str == null && prefix == null);
        }
        if (prefix.length() > str.length()) {
            return false;
        }
        return str.regionMatches(ignoreCase, 0, prefix, 0, prefix.length());
    }
    /**
     * Gets a String's length or <code>0</code> if the String is <code>null</code>.
     *
     * @param str
     *            a String or <code>null</code>
     * @return String length or <code>0</code> if the String is <code>null</code>.
     * @since 2.4
     */
    public static int length(String str) {
        return str == null ? 0 : str.length();
    }
}

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