1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.harmony.luni.tests.java.util; 19 20 import java.util.Random; 21 22 public class RandomTest extends junit.framework.TestCase { 23 24 Random r; 25 26 /** 27 * @tests java.util.Random#Random() 28 */ 29 public void test_Constructor() { 30 // Test for method java.util.Random() 31 assertTrue("Used to test", true); 32 } 33 34 /** 35 * @tests java.util.Random#Random(long) 36 */ 37 public void test_ConstructorJ() { 38 Random r = new Random(8409238L); 39 Random r2 = new Random(8409238L); 40 for (int i = 0; i < 100; i++) 41 assertTrue("Values from randoms with same seed don't match", r 42 .nextInt() == r2.nextInt()); 43 } 44 45 /** 46 * @tests java.util.Random#nextBoolean() 47 */ 48 public void test_nextBoolean() { 49 // Test for method boolean java.util.Random.nextBoolean() 50 boolean falseAppeared = false, trueAppeared = false; 51 for (int counter = 0; counter < 100; counter++) 52 if (r.nextBoolean()) 53 trueAppeared = true; 54 else 55 falseAppeared = true; 56 assertTrue("Calling nextBoolean() 100 times resulted in all trues", 57 falseAppeared); 58 assertTrue("Calling nextBoolean() 100 times resulted in all falses", 59 trueAppeared); 60 } 61 62 /** 63 * @tests java.util.Random#nextBytes(byte[]) 64 */ 65 public void test_nextBytes$B() { 66 // Test for method void java.util.Random.nextBytes(byte []) 67 boolean someDifferent = false; 68 byte[] randomBytes = new byte[100]; 69 r.nextBytes(randomBytes); 70 byte firstByte = randomBytes[0]; 71 for (int counter = 1; counter < randomBytes.length; counter++) 72 if (randomBytes[counter] != firstByte) 73 someDifferent = true; 74 assertTrue( 75 "nextBytes() returned an array of length 100 of the same byte", 76 someDifferent); 77 } 78 79 /** 80 * @tests java.util.Random#nextDouble() 81 */ 82 public void test_nextDouble() { 83 // Test for method double java.util.Random.nextDouble() 84 double lastNum = r.nextDouble(); 85 double nextNum; 86 boolean someDifferent = false; 87 boolean inRange = true; 88 for (int counter = 0; counter < 100; counter++) { 89 nextNum = r.nextDouble(); 90 if (nextNum != lastNum) 91 someDifferent = true; 92 if (!(0 <= nextNum && nextNum < 1.0)) 93 inRange = false; 94 lastNum = nextNum; 95 } 96 assertTrue("Calling nextDouble 100 times resulted in same number", 97 someDifferent); 98 assertTrue( 99 "Calling nextDouble resulted in a number out of range [0,1)", 100 inRange); 101 } 102 103 /** 104 * @tests java.util.Random#nextFloat() 105 */ 106 public void test_nextFloat() { 107 // Test for method float java.util.Random.nextFloat() 108 float lastNum = r.nextFloat(); 109 float nextNum; 110 boolean someDifferent = false; 111 boolean inRange = true; 112 for (int counter = 0; counter < 100; counter++) { 113 nextNum = r.nextFloat(); 114 if (nextNum != lastNum) 115 someDifferent = true; 116 if (!(0 <= nextNum && nextNum < 1.0)) 117 inRange = false; 118 lastNum = nextNum; 119 } 120 assertTrue("Calling nextFloat 100 times resulted in same number", 121 someDifferent); 122 assertTrue("Calling nextFloat resulted in a number out of range [0,1)", 123 inRange); 124 } 125 126 /** 127 * @tests java.util.Random#nextGaussian() 128 */ 129 public void test_nextGaussian() { 130 // Test for method double java.util.Random.nextGaussian() 131 double lastNum = r.nextGaussian(); 132 double nextNum; 133 boolean someDifferent = false; 134 boolean someInsideStd = false; 135 for (int counter = 0; counter < 100; counter++) { 136 nextNum = r.nextGaussian(); 137 if (nextNum != lastNum) 138 someDifferent = true; 139 if (-1.0 <= nextNum && nextNum <= 1.0) 140 someInsideStd = true; 141 lastNum = nextNum; 142 } 143 assertTrue("Calling nextGaussian 100 times resulted in same number", 144 someDifferent); 145 assertTrue( 146 "Calling nextGaussian 100 times resulted in no number within 1 std. deviation of mean", 147 someInsideStd); 148 } 149 150 /** 151 * @tests java.util.Random#nextInt() 152 */ 153 public void test_nextInt() { 154 // Test for method int java.util.Random.nextInt() 155 int lastNum = r.nextInt(); 156 int nextNum; 157 boolean someDifferent = false; 158 for (int counter = 0; counter < 100; counter++) { 159 nextNum = r.nextInt(); 160 if (nextNum != lastNum) 161 someDifferent = true; 162 lastNum = nextNum; 163 } 164 assertTrue("Calling nextInt 100 times resulted in same number", 165 someDifferent); 166 } 167 168 /** 169 * @tests java.util.Random#nextInt(int) 170 */ 171 public void test_nextIntI() { 172 // Test for method int java.util.Random.nextInt(int) 173 final int range = 10; 174 int lastNum = r.nextInt(range); 175 int nextNum; 176 boolean someDifferent = false; 177 boolean inRange = true; 178 for (int counter = 0; counter < 100; counter++) { 179 nextNum = r.nextInt(range); 180 if (nextNum != lastNum) 181 someDifferent = true; 182 if (!(0 <= nextNum && nextNum < range)) 183 inRange = false; 184 lastNum = nextNum; 185 } 186 assertTrue("Calling nextInt (range) 100 times resulted in same number", 187 someDifferent); 188 assertTrue( 189 "Calling nextInt (range) resulted in a number outside of [0, range)", 190 inRange); 191 192 } 193 194 /** 195 * @tests java.util.Random#nextLong() 196 */ 197 public void test_nextLong() { 198 // Test for method long java.util.Random.nextLong() 199 long lastNum = r.nextLong(); 200 long nextNum; 201 boolean someDifferent = false; 202 for (int counter = 0; counter < 100; counter++) { 203 nextNum = r.nextLong(); 204 if (nextNum != lastNum) 205 someDifferent = true; 206 lastNum = nextNum; 207 } 208 assertTrue("Calling nextLong 100 times resulted in same number", 209 someDifferent); 210 } 211 212 /** 213 * @tests java.util.Random#setSeed(long) 214 */ 215 public void test_setSeedJ() { 216 // Test for method void java.util.Random.setSeed(long) 217 long[] randomArray = new long[100]; 218 boolean someDifferent = false; 219 final long firstSeed = 1000; 220 long aLong, anotherLong, yetAnotherLong; 221 Random aRandom = new Random(); 222 Random anotherRandom = new Random(); 223 Random yetAnotherRandom = new Random(); 224 aRandom.setSeed(firstSeed); 225 anotherRandom.setSeed(firstSeed); 226 for (int counter = 0; counter < randomArray.length; counter++) { 227 aLong = aRandom.nextLong(); 228 anotherLong = anotherRandom.nextLong(); 229 assertTrue( 230 "Two randoms with same seeds gave differing nextLong values", 231 aLong == anotherLong); 232 yetAnotherLong = yetAnotherRandom.nextLong(); 233 randomArray[counter] = aLong; 234 if (aLong != yetAnotherLong) 235 someDifferent = true; 236 } 237 assertTrue( 238 "Two randoms with the different seeds gave the same chain of values", 239 someDifferent); 240 aRandom.setSeed(firstSeed); 241 for (int counter = 0; counter < randomArray.length; counter++) 242 assertTrue( 243 "Reseting a random to its old seed did not result in the same chain of values as it gave before", 244 aRandom.nextLong() == randomArray[counter]); 245 } 246 247 // two random create at a time should also generated different results 248 // regression test for Harmony 4616 249 public void test_random_generate() throws Exception { 250 for (int i = 0; i < 100; i++) { 251 Random random1 = new Random(); 252 Random random2 = new Random(); 253 assertFalse(random1.nextLong() == random2.nextLong()); 254 } 255 } 256 257 258 /** 259 * Sets up the fixture, for example, open a network connection. This method 260 * is called before a test is executed. 261 */ 262 protected void setUp() { 263 r = new Random(); 264 } 265 266 /** 267 * Tears down the fixture, for example, close a network connection. This 268 * method is called after a test is executed. 269 */ 270 protected void tearDown() { 271 } 272 } 273
