1 /*

     2  * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 /*

    27  * This file is available under and governed by the GNU General Public

    28  * License version 2 only, as published by the Free Software Foundation.

    29  * However, the following notice accompanied the original version of this

    30  * file:

    31  *

    32  * The MIT License

    33  *

    34  * Copyright (c) 2004-2014 Paul R. Holser, Jr.

    35  *

    36  * Permission is hereby granted, free of charge, to any person obtaining

    37  * a copy of this software and associated documentation files (the

    38  * "Software"), to deal in the Software without restriction, including

    39  * without limitation the rights to use, copy, modify, merge, publish,

    40  * distribute, sublicense, and/or sell copies of the Software, and to

    41  * permit persons to whom the Software is furnished to do so, subject to

    42  * the following conditions:

    43  *

    44  * The above copyright notice and this permission notice shall be

    45  * included in all copies or substantial portions of the Software.

    46  *

    47  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

    48  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

    49  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

    50  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE

    51  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION

    52  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

    53  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    54  */

    55 

    56 package jdk.internal.joptsimple.internal;

    57 

    58 import java.util.Iterator;

    59 import java.util.List;

    60 

    61 import static java.lang.System.*;

    62 import static java.util.Arrays.*;

    63 

    64 /**

    65  * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>

    66  */

    67 public final class Strings {

    68     public static final String EMPTY = "";

    69     public static final String SINGLE_QUOTE = "'";

    70     public static final String LINE_SEPARATOR = getProperty( "line.separator" );

    71 

    72     private Strings() {

    73         throw new UnsupportedOperationException();

    74     }

    75 

    76     /**

    77      * Gives a string consisting of the given character repeated the given number of times.

    78      *

    79      * @param ch the character to repeat

    80      * @param count how many times to repeat the character

    81      * @return the resultant string

    82      */

    83     public static String repeat( char ch, int count ) {

    84         StringBuilder buffer = new StringBuilder();

    85 

    86         for ( int i = 0; i < count; ++i )

    87             buffer.append( ch );

    88 

    89         return buffer.toString();

    90     }

    91 

    92     /**

    93      * Tells whether the given string is either {@code} or consists solely of whitespace characters.

    94      *

    95      * @param target string to check

    96      * @return {@code true} if the target string is null or empty

    97      */

    98     public static boolean isNullOrEmpty( String target ) {

    99         return target == null || EMPTY.equals( target );

   100     }

   101 

   102 

   103     /**

   104      * Gives a string consisting of a given string prepended and appended with surrounding characters.

   105      *

   106      * @param target a string

   107      * @param begin character to prepend

   108      * @param end character to append

   109      * @return the surrounded string

   110      */

   111     public static String surround( String target, char begin, char end ) {

   112         return begin + target + end;

   113     }

   114 

   115     /**

   116      * Gives a string consisting of the elements of a given array of strings, each separated by a given separator

   117      * string.

   118      *

   119      * @param pieces the strings to join

   120      * @param separator the separator

   121      * @return the joined string

   122      */

   123     public static String join( String[] pieces, String separator ) {

   124         return join( asList( pieces ), separator );

   125     }

   126 

   127     /**

   128      * Gives a string consisting of the string representations of the elements of a given array of objects,

   129      * each separated by a given separator string.

   130      *

   131      * @param pieces the elements whose string representations are to be joined

   132      * @param separator the separator

   133      * @return the joined string

   134      */

   135     public static String join( List<String> pieces, String separator ) {

   136         StringBuilder buffer = new StringBuilder();

   137 

   138         for ( Iterator<String> iter = pieces.iterator(); iter.hasNext(); ) {

   139             buffer.append( iter.next() );

   140 

   141             if ( iter.hasNext() )

   142                 buffer.append( separator );

   143         }

   144 

   145         return buffer.toString();

   146     }

   147 }