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 * @author Elena Semukhina 19 */ 20 21 package org.apache.harmony.tests.java.math; 22 23 import java.math.BigInteger; 24 25 import junit.framework.TestCase; 26 27 /** 28 * Class: java.math.BigInteger 29 * Method: hashCode() 30 */ 31 public class BigIntegerHashCodeTest extends TestCase { 32 /** 33 * Test hash codes for the same object 34 */ 35 public void testSameObject() { 36 String value1 = "12378246728727834290276457386374882976782849"; 37 String value2 = "-5634562095872038262928728727834290276457386374882976782849"; 38 BigInteger aNumber1 = new BigInteger(value1); 39 BigInteger aNumber2 = new BigInteger(value2); 40 int code1 = aNumber1.hashCode(); 41 aNumber1.add(aNumber2).shiftLeft(125); 42 aNumber1.subtract(aNumber2).shiftRight(125); 43 aNumber1.multiply(aNumber2).toByteArray(); 44 aNumber1.divide(aNumber2).bitLength(); 45 aNumber1.gcd(aNumber2).pow(7); 46 int code2 = aNumber1.hashCode(); 47 assertTrue("hash codes for the same object differ", code1 == code2); 48 } 49 50 /** 51 * Test hash codes for equal objects. 52 */ 53 public void testEqualObjects() { 54 String value1 = "12378246728727834290276457386374882976782849"; 55 String value2 = "12378246728727834290276457386374882976782849"; 56 BigInteger aNumber1 = new BigInteger(value1); 57 BigInteger aNumber2 = new BigInteger(value2); 58 int code1 = aNumber1.hashCode(); 59 int code2 = aNumber2.hashCode(); 60 if (aNumber1.equals(aNumber2)) { 61 assertTrue("hash codes for equal objects are unequal", code1 == code2); 62 } 63 } 64 65 /** 66 * Test hash codes for unequal objects. 67 * The codes are unequal. 68 */ 69 public void testUnequalObjectsUnequal() { 70 String value1 = "12378246728727834290276457386374882976782849"; 71 String value2 = "-5634562095872038262928728727834290276457386374882976782849"; 72 BigInteger aNumber1 = new BigInteger(value1); 73 BigInteger aNumber2 = new BigInteger(value2); 74 int code1 = aNumber1.hashCode(); 75 int code2 = aNumber2.hashCode(); 76 if (!aNumber1.equals(aNumber2)) { 77 assertTrue("hash codes for unequal objects are equal", code1 != code2); 78 } 79 } 80 } 81
