From 17fde6ddfacfbcc350d3037fb39c311ccfbf5d9c Mon Sep 17 00:00:00 2001 From: Arjen Poutsma Date: Thu, 30 Oct 2008 15:07:00 +0000 Subject: [PATCH] Added MD5 hashing utils. git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@205 50f2f4bb-b051-0410-bef5-90022cba6387 --- .../springframework/util/Md5HashUtils.java | 83 +++++++++++++++++++ .../util/Md5HashUtilsTests.java | 57 +++++++++++++ 2 files changed, 140 insertions(+) create mode 100644 org.springframework.core/src/main/java/org/springframework/util/Md5HashUtils.java create mode 100644 org.springframework.core/src/test/java/org/springframework/util/Md5HashUtilsTests.java diff --git a/org.springframework.core/src/main/java/org/springframework/util/Md5HashUtils.java b/org.springframework.core/src/main/java/org/springframework/util/Md5HashUtils.java new file mode 100644 index 00000000000..9e061f603c7 --- /dev/null +++ b/org.springframework.core/src/main/java/org/springframework/util/Md5HashUtils.java @@ -0,0 +1,83 @@ +/* + * Copyright 2008 the original author or authors. + * + * Licensed 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.springframework.util; + +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; + +/** + * Miscellaneous method for calculating MD5 hashes. + * + * @author Arjen Poutsma + * @since 3.0 + */ +public abstract class Md5HashUtils { + + private static final char[] HEX_CHARS = + {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f',}; + + /** + * Calculates the MD5 hash of the given bytes. + * + * @param bytes the bytes to calculate the hash over + * @return the hash + */ + public static byte[] getHash(byte[] bytes) { + try { + // MessageDigest is not thread-safe + MessageDigest messageDigest = MessageDigest.getInstance("MD5"); + return messageDigest.digest(bytes); + } + catch (NoSuchAlgorithmException ex) { + throw new IllegalStateException("Could not find MD5 MessageDigest instance", ex); + } + } + + private static char[] getHashChars(byte[] bytes) { + byte[] hash = getHash(bytes); + char chars[] = new char[32]; + for (int i = 0; i < chars.length; i = i + 2) { + byte b = hash[i / 2]; + chars[i] = HEX_CHARS[(b >>> 0x4) & 0xf]; + chars[i + 1] = HEX_CHARS[b & 0xf]; + } + return chars; + } + + /** + * Returns a hex string representation of the MD5 hash of the given bytes. + * + * @param bytes the bytes to calculate the hash over + * @return a hexadecimal hash string + */ + public static String getHashString(byte[] bytes) { + return new String(getHashChars(bytes)); + } + + /** + * Appends a hex string representation of the MD5 hash of the given bytes to the given {@link StringBuilder}. + * + * @param bytes the bytes to calculate the hash over + * @param builder the string builder to append the hash to + * @return the given string builder + */ + public static StringBuilder appendHashString(byte[] bytes, StringBuilder builder) { + builder.append(getHashChars(bytes)); + return builder; + } + +} diff --git a/org.springframework.core/src/test/java/org/springframework/util/Md5HashUtilsTests.java b/org.springframework.core/src/test/java/org/springframework/util/Md5HashUtilsTests.java new file mode 100644 index 00000000000..299b50d3225 --- /dev/null +++ b/org.springframework.core/src/test/java/org/springframework/util/Md5HashUtilsTests.java @@ -0,0 +1,57 @@ +/* + * Copyright ${YEAR} the original author or authors. + * + * Licensed 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.springframework.util; + +import java.io.UnsupportedEncodingException; + +import static org.junit.Assert.assertArrayEquals; +import static org.junit.Assert.assertEquals; +import org.junit.Before; +import org.junit.Test; + +public class Md5HashUtilsTests { + + private byte[] bytes; + + @Before + public void createBytes() throws UnsupportedEncodingException { + bytes = "Hello World".getBytes("UTF-8"); + } + + @Test + public void hash() { + byte[] result = Md5HashUtils.getHash(bytes); + byte[] expected = new byte[]{-0x4f, 0xa, -0x73, -0x4f, 0x64, -0x20, 0x75, 0x41, 0x5, -0x49, -0x57, -0x65, -0x19, + 0x2e, 0x3f, -0x1b}; + assertArrayEquals("Invalid hash", expected, result); + } + + @Test + public void hashString() throws UnsupportedEncodingException { + String hash = Md5HashUtils.getHashString(bytes); + assertEquals("Invalid hash", "b10a8db164e0754105b7a99be72e3fe5", hash); + } + + @Test + public void hashStringBuilder() throws UnsupportedEncodingException { + StringBuilder builder = new StringBuilder(); + Md5HashUtils.appendHashString(bytes, builder); + assertEquals("Invalid hash", "b10a8db164e0754105b7a99be72e3fe5", builder.toString()); + } + + +} \ No newline at end of file