< prev index next >

test/jdk/java/util/Collections/NCopies.java

Print this page


   1 /*
   2  * Copyright (c) 2005, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug     6267846 6275009
  27  * @summary Test Collections.nCopies
  28  * @author  Martin Buchholz
  29  */
  30 

  31 import java.util.Collections;

  32 import java.util.List;

  33 
  34 public class NCopies {
  35     static volatile int passed = 0, failed = 0;
  36 
  37     static void fail(String msg) {
  38         failed++;
  39         new AssertionError(msg).printStackTrace();
  40     }
  41 
  42     static void pass() {
  43         passed++;
  44     }
  45 
  46     static void unexpected(Throwable t) {
  47         failed++;
  48         t.printStackTrace();
  49     }
  50 
  51     static void check(boolean condition, String msg) {
  52         if (condition)


  65             check(x.indexOf("foo") == -1);
  66             check(x.lastIndexOf("foo") == -1);
  67             check(x.toArray().length == 0);
  68             check(x.toArray().getClass() == Object[].class);
  69     }
  70 
  71     private static void checkFoos(List<String> x) {
  72             check(! x.isEmpty());
  73             check(x.indexOf(new String("foo")) == 0);
  74             check(x.lastIndexOf(new String("foo")) == x.size()-1);
  75             check(x.toArray().length == x.size());
  76             check(x.toArray().getClass() == Object[].class);
  77             String[] sa = x.toArray(new String[x.size()]);
  78             check(sa.getClass() == String[].class);
  79             check(sa[0].equals("foo"));
  80             check(sa[sa.length-1].equals("foo"));
  81             check(x.get(x.size()/2).equals("foo"));
  82             checkEmpty(x.subList(x.size()/2, x.size()/2));
  83     }
  84 


















































  85     public static void main(String[] args) {
  86         try {
  87             List<String> empty = Collections.nCopies(0, "foo");
  88             checkEmpty(empty);
  89             checkEmpty(empty.subList(0,0));
  90 
  91             List<String> foos = Collections.nCopies(42, "foo");
  92             check(foos.size() == 42);
  93             checkFoos(foos.subList(foos.size()/2, foos.size()-1));




  94 
  95         } catch (Throwable t) { unexpected(t); }
  96 
  97         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
  98         if (failed > 0) throw new Error("Some tests failed");
  99     }
 100 }
   1 /*
   2  * Copyright (c) 2005, 2018, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug     6267846 6275009
  27  * @summary Test Collections.nCopies
  28  * @author  Martin Buchholz
  29  */
  30 
  31 import java.util.ArrayList;
  32 import java.util.Collections;
  33 import java.util.AbstractList;
  34 import java.util.List;
  35 import java.util.Objects;
  36 
  37 public class NCopies {
  38     static volatile int passed = 0, failed = 0;
  39 
  40     static void fail(String msg) {
  41         failed++;
  42         new AssertionError(msg).printStackTrace();
  43     }
  44 
  45     static void pass() {
  46         passed++;
  47     }
  48 
  49     static void unexpected(Throwable t) {
  50         failed++;
  51         t.printStackTrace();
  52     }
  53 
  54     static void check(boolean condition, String msg) {
  55         if (condition)


  68             check(x.indexOf("foo") == -1);
  69             check(x.lastIndexOf("foo") == -1);
  70             check(x.toArray().length == 0);
  71             check(x.toArray().getClass() == Object[].class);
  72     }
  73 
  74     private static void checkFoos(List<String> x) {
  75             check(! x.isEmpty());
  76             check(x.indexOf(new String("foo")) == 0);
  77             check(x.lastIndexOf(new String("foo")) == x.size()-1);
  78             check(x.toArray().length == x.size());
  79             check(x.toArray().getClass() == Object[].class);
  80             String[] sa = x.toArray(new String[x.size()]);
  81             check(sa.getClass() == String[].class);
  82             check(sa[0].equals("foo"));
  83             check(sa[sa.length-1].equals("foo"));
  84             check(x.get(x.size()/2).equals("foo"));
  85             checkEmpty(x.subList(x.size()/2, x.size()/2));
  86     }
  87     
  88     private static <T> List<T> referenceNCopies(int n, T o) {
  89         // A simplest correct implementation of nCopies to compare with the actual optimized implementation
  90         return new AbstractList<>() {
  91             public int size() { return n; }
  92 
  93             public T get(int index) {
  94                 Objects.checkIndex(index, n);
  95                 return o;
  96             }
  97         };
  98     }
  99     
 100     private static void checkHashCode() {
 101         int[] sizes = {0, 1, 2, 3, 5, 10, 31, 32, 100, 1000};
 102         String[] elements = {null, "non-null"};
 103         for (int size : sizes) {
 104             for (String element : elements) {
 105                 int expectedHashCode = referenceNCopies(size, element).hashCode();
 106                 int actualHashCode = Collections.nCopies(size, element).hashCode();
 107                 check(expectedHashCode == actualHashCode,
 108                         "Collections.nCopies(" + size + ", " + element + ").hashCode()");
 109             }
 110         }
 111     }
 112     
 113     private static void checkEquals() {
 114         int[][] sizePairs = {{0, 0}, {0, 1}, {1, 0}, {1, 1}, {1, 2}, {2, 1}};
 115         String[] elements = {null, "non-null"};
 116         for (int[] pair : sizePairs) {
 117             for (String element : elements) {
 118                 boolean equal = pair[0] == pair[1];
 119                 String msg = "[" + pair[0] + ", " + element + "] <=> [" + pair[1] + ", " + element + "]";
 120                 check(equal == Collections.nCopies(pair[0], element).equals(Collections.nCopies(pair[1], element)), msg);
 121                 check(equal == Collections.nCopies(pair[0], element).equals(referenceNCopies(pair[1], element)), msg);
 122                 check(equal == referenceNCopies(pair[0], element).equals(Collections.nCopies(pair[1], element)), msg);
 123             }
 124         }
 125         List<String> nulls = Collections.nCopies(10, null);
 126         List<String> nonNulls = Collections.nCopies(10, "non-null");
 127         List<String> nullsButOne = new ArrayList<>(nulls);
 128         nullsButOne.set(9, "non-null");
 129         List<String> nonNullsButOne = new ArrayList<>(nonNulls);
 130         nonNullsButOne.set(9, null);
 131         check(!nulls.equals(nonNulls));
 132         check(!nulls.equals(nullsButOne));
 133         check(!nulls.equals(nonNullsButOne));
 134         check(!nonNulls.equals(nonNullsButOne));
 135         check(Collections.nCopies(0, null).equals(Collections.nCopies(0, "non-null")));
 136     }
 137 
 138     public static void main(String[] args) {
 139         try {
 140             List<String> empty = Collections.nCopies(0, "foo");
 141             checkEmpty(empty);
 142             checkEmpty(empty.subList(0,0));
 143 
 144             List<String> foos = Collections.nCopies(42, "foo");
 145             check(foos.size() == 42);
 146             checkFoos(foos.subList(foos.size()/2, foos.size()-1));
 147 
 148             checkHashCode();
 149 
 150             checkEquals();
 151 
 152         } catch (Throwable t) { unexpected(t); }
 153 
 154         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
 155         if (failed > 0) throw new Error("Some tests failed");
 156     }
 157 }
< prev index next >