TestMD5Hash.java
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上传日期:2018-01-08
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- /**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.apache.hadoop.io;
- import org.apache.hadoop.io.TestWritable;
- import junit.framework.TestCase;
- import java.security.MessageDigest;
- import java.util.Random;
- /** Unit tests for MD5Hash. */
- public class TestMD5Hash extends TestCase {
- public TestMD5Hash(String name) { super(name); }
- private static final Random RANDOM = new Random();
- public static MD5Hash getTestHash() throws Exception {
- MessageDigest digest = MessageDigest.getInstance("MD5");
- byte[] buffer = new byte[1024];
- RANDOM.nextBytes(buffer);
- digest.update(buffer);
- return new MD5Hash(digest.digest());
- }
- protected static byte[] D00 = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
- protected static byte[] DFF = new byte[] {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
-
- public void testMD5Hash() throws Exception {
- MD5Hash md5Hash = getTestHash();
- final MD5Hash md5Hash00
- = new MD5Hash(D00);
- final MD5Hash md5HashFF
- = new MD5Hash(DFF);
-
- MD5Hash orderedHash = new MD5Hash(new byte[]{1,2,3,4,5,6,7,8,9,10,11,12,
- 13,14,15,16});
- MD5Hash backwardHash = new MD5Hash(new byte[]{-1,-2,-3,-4,-5,-6,-7,-8,
- -9,-10,-11,-12, -13, -14,
- -15,-16});
- MD5Hash closeHash1 = new MD5Hash(new byte[]{-1,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0});
- MD5Hash closeHash2 = new MD5Hash(new byte[]{-1,1,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0});
- // test i/o
- TestWritable.testWritable(md5Hash);
- TestWritable.testWritable(md5Hash00);
- TestWritable.testWritable(md5HashFF);
- // test equals()
- assertEquals(md5Hash, md5Hash);
- assertEquals(md5Hash00, md5Hash00);
- assertEquals(md5HashFF, md5HashFF);
- // test compareTo()
- assertTrue(md5Hash.compareTo(md5Hash) == 0);
- assertTrue(md5Hash00.compareTo(md5Hash) < 0);
- assertTrue(md5HashFF.compareTo(md5Hash) > 0);
- // test toString and string ctor
- assertEquals(md5Hash, new MD5Hash(md5Hash.toString()));
- assertEquals(md5Hash00, new MD5Hash(md5Hash00.toString()));
- assertEquals(md5HashFF, new MD5Hash(md5HashFF.toString()));
- assertEquals(0x01020304, orderedHash.quarterDigest());
- assertEquals(0xfffefdfc, backwardHash.quarterDigest());
-
- assertEquals(0x0102030405060708L, orderedHash.halfDigest());
- assertEquals(0xfffefdfcfbfaf9f8L, backwardHash.halfDigest());
- assertTrue("hash collision",
- closeHash1.hashCode() != closeHash2.hashCode());
-
- Thread t1 = new Thread() {
- public void run() {
- for (int i = 0; i < 100; i++) {
- MD5Hash hash = new MD5Hash(DFF);
- assertEquals(hash, md5HashFF);
- }
- }
- };
-
- Thread t2 = new Thread() {
- public void run() {
- for (int i = 0; i < 100; i++) {
- MD5Hash hash = new MD5Hash(D00);
- assertEquals(hash, md5Hash00);
- }
- }
- };
-
- t1.start();
- t2.start();
- t1.join();
- t2.join();
-
- }
-
- }