1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package libcore.java.util; 18 19 import java.util.Arrays; 20 import java.util.Random; 21 22 public class RandomTest extends junit.framework.TestCase { 23 public void test_subclassing() throws Exception { 24 // http://b/2502231 25 // Ensure that Random's constructors call setSeed by emulating the active ingredient 26 // from the bug: the subclass' setSeed had a side-effect necessary for the correct 27 // functioning of next. 28 class MyRandom extends Random { 29 public String state; 30 public MyRandom() { super(); } 31 public MyRandom(long l) { super(l); } 32 @Override protected synchronized int next(int bits) { return state.length(); } 33 @Override public synchronized void setSeed(long seed) { state = Long.toString(seed); } 34 } 35 // Test the 0-argument constructor... 36 MyRandom r1 = new MyRandom(); 37 r1.nextInt(); 38 assertNotNull(r1.state); 39 // Test the 1-argument constructor... 40 MyRandom r2 = new MyRandom(123L); 41 r2.nextInt(); 42 assertNotNull(r2.state); 43 } 44 45 public void test_ints$() { 46 final int limit = 128; // We can't test for every element in an infinite stream. 47 48 Random rand = new Random(0); 49 int[] rands = new int[limit]; 50 for(int i = 0; i < limit; ++i) { 51 rands[i] = rand.nextInt(); 52 } 53 54 int[] streamRands = new Random(0).ints().limit(limit).toArray(); 55 assertTrue(Arrays.equals(rands, streamRands)); 56 } 57 58 public void test_ints$L() { 59 final int size = 32; 60 61 Random rand = new Random(0); 62 int[] rands = new int[size]; 63 for(int i = 0; i < size; ++i) { 64 rands[i] = rand.nextInt(); 65 } 66 67 int[] streamRands = new Random(0).ints(size).toArray(); 68 assertTrue(Arrays.equals(rands, streamRands)); 69 assertEquals(size, new Random(0).ints(size).count()); 70 71 try { 72 new Random(0).ints(-1); 73 fail(); 74 } catch (IllegalArgumentException expected) {} 75 } 76 77 public void test_ints$II() { 78 final int limit = 128; // We can't test for every element in an infinite stream. 79 final int origin = 128, bound = 256; 80 81 Random rand = new Random(0); 82 int[] rands = new int[limit]; 83 for(int i = 0; i < limit; ++i) { 84 rands[i] = rand.nextInt(bound - origin) + origin; 85 } 86 87 int[] streamRands = new Random(0).ints(origin, bound).limit(limit).toArray(); 88 assertTrue(Arrays.equals(rands, streamRands)); 89 90 try { 91 new Random(0).ints(100, 0); 92 fail(); 93 } catch (IllegalArgumentException expected) {} 94 } 95 96 public void test_ints$LII() { 97 final int size = 32; 98 final int origin = 128, bound = 256; 99 100 Random rand = new Random(0); 101 int[] rands = new int[size]; 102 for(int i = 0; i < size; ++i) { 103 rands[i] = rand.nextInt(bound - origin) + origin; 104 } 105 106 int[] streamRands = new Random(0).ints(size, origin, bound).toArray(); 107 assertTrue(Arrays.equals(rands, streamRands)); 108 assertEquals(size, new Random(0).ints(size, origin, bound).count()); 109 110 try { 111 new Random(0).ints(-1, 10, 20); 112 fail(); 113 } catch (IllegalArgumentException expected) {} 114 try { 115 new Random(0).ints(10, 100, 0); 116 fail(); 117 } catch (IllegalArgumentException expected) {} 118 } 119 120 public void test_longs$() { 121 final int limit = 128; // We can't test for every element in an infinite stream. 122 123 Random rand = new Random(0); 124 long[] rands = new long[limit]; 125 for(int i = 0; i < limit; ++i) { 126 rands[i] = rand.nextLong(); 127 } 128 129 long[] streamRands = new Random(0).longs().limit(limit).toArray(); 130 assertTrue(Arrays.equals(rands, streamRands)); 131 } 132 133 public void test_longs$L() { 134 final int size = 32; 135 136 Random rand = new Random(0); 137 long[] rands = new long[size]; 138 for(int i = 0; i < size; ++i) { 139 rands[i] = rand.nextLong(); 140 } 141 142 long[] streamRands = new Random(0).longs(size).toArray(); 143 assertTrue(Arrays.equals(rands, streamRands)); 144 assertEquals(size, new Random(0).longs(size).count()); 145 146 try { 147 new Random(0).longs(-1); 148 fail(); 149 } catch (IllegalArgumentException expected) {} 150 } 151 152 public void test_longs$II() { 153 final int limit = 128; // We can't test for every element in an infinite stream. 154 final int origin = 128, bound = 256; 155 156 Random rand = new Random(0); 157 long[] rands = new long[limit]; 158 for(int i = 0; i < limit; ++i) { 159 rands[i] = (rand.nextLong() & 127) + origin; 160 } 161 162 long[] streamRands = new Random(0).longs(origin, bound).limit(limit).toArray(); 163 assertTrue(Arrays.equals(rands, streamRands)); 164 165 try { 166 new Random(0).longs(100, 0); 167 fail(); 168 } catch (IllegalArgumentException expected) {} 169 } 170 171 public void test_longs$LII() { 172 final int size = 32; 173 final int origin = 128, bound = 256; 174 175 Random rand = new Random(0); 176 long[] rands = new long[size]; 177 for(int i = 0; i < size; ++i) { 178 rands[i] = (rand.nextLong() & 127) + origin; 179 } 180 181 long[] streamRands = new Random(0).longs(size, origin, bound).toArray(); 182 assertTrue(Arrays.equals(rands, streamRands)); 183 assertEquals(size, new Random(0).longs(size, origin, bound).count()); 184 185 try { 186 new Random(0).longs(-1, 10, 20); 187 fail(); 188 } catch (IllegalArgumentException expected) {} 189 try { 190 new Random(0).longs(10, 100, 0); 191 fail(); 192 } catch (IllegalArgumentException expected) {} 193 } 194 195 public void test_doubles$() { 196 final int limit = 128; // We can't test for every element in an infinite stream. 197 198 Random rand = new Random(0); 199 double[] rands = new double[limit]; 200 for(int i = 0; i < limit; ++i) { 201 rands[i] = rand.nextDouble(); 202 } 203 204 double[] streamRands = new Random(0).doubles().limit(limit).toArray(); 205 assertTrue(Arrays.equals(rands, streamRands)); 206 } 207 208 public void test_doubles$L() { 209 final int size = 32; 210 211 Random rand = new Random(0); 212 double[] rands = new double[size]; 213 for(int i = 0; i < size; ++i) { 214 rands[i] = rand.nextDouble(); 215 } 216 217 double[] streamRands = new Random(0).doubles(size).toArray(); 218 assertTrue(Arrays.equals(rands, streamRands)); 219 assertEquals(size, new Random(0).doubles(size).count()); 220 221 try { 222 new Random(0).ints(-1); 223 fail(); 224 } catch (IllegalArgumentException expected) {} 225 } 226 227 public void test_doubles$II() { 228 final int limit = 128; // We can't test for every element in an infinite stream. 229 final int origin = 128, bound = 256; 230 231 Random rand = new Random(0); 232 double[] rands = new double[limit]; 233 for(int i = 0; i < limit; ++i) { 234 double r = rand.nextDouble() * (bound - origin) + origin; 235 if (r >= bound) { 236 r = Math.nextDown(r); 237 } 238 rands[i] = r; 239 } 240 241 double[] streamRands = new Random(0).doubles(origin, bound).limit(limit).toArray(); 242 assertTrue(Arrays.equals(rands, streamRands)); 243 244 try { 245 new Random(0).doubles(100, 0); 246 fail(); 247 } catch (IllegalArgumentException expected) {} 248 } 249 250 public void test_doubles$LII() { 251 final int size = 32; 252 final int origin = 128, bound = 256; 253 254 Random rand = new Random(0); 255 double[] rands = new double[size]; 256 for(int i = 0; i < size; ++i) { 257 double r = rand.nextDouble() * (bound - origin) + origin; 258 if (r >= bound) { 259 r = Math.nextDown(r); 260 } 261 rands[i] = r; 262 } 263 264 double[] streamRands = new Random(0).doubles(size, origin, bound).toArray(); 265 assertTrue(Arrays.equals(rands, streamRands)); 266 assertEquals(size, new Random(0).doubles(size, origin, bound).count()); 267 268 try { 269 new Random(0).doubles(-1, 10, 20); 270 fail(); 271 } catch (IllegalArgumentException expected) {} 272 try { 273 new Random(0).doubles(10, 100, 0); 274 fail(); 275 } catch (IllegalArgumentException expected) {} 276 } 277 } 278
