Fixes #1. Memcached key is too long.

Author: emacarron

pom.xml

@@ -20,7 +20,7 @@
   <parent>
     <groupId>org.mybatis</groupId>
     <artifactId>mybatis-parent</artifactId>
-    <version>19-SNAPSHOT</version>
+    <version>21</version>
   </parent>
 
   <groupId>org.mybatis.caches</groupId>

src/main/java/org/mybatis/caches/memcached/MemcachedClientWrapper.java

@@ -57,13 +57,13 @@ public MemcachedClientWrapper() {
     }
 
     /**
-     * Converts the iBatis object key in the proper string representation.
-     *
-     * @param key the iBatis object key.
+     * Converts the MyBatis object key in the proper string representation.
+     * 
+     * @param key the MyBatis object key.
      * @return the proper string representation.
      */
     private String toKeyString(final Object key) {
-        String keyString = configuration.getKeyPrefix() + key; // issue #660, key collision
+	String keyString = configuration.getKeyPrefix() + StringUtils.sha1Hex(key.toString()); // issue #1, key too long
         if (log.isDebugEnabled()) {
             log.debug("Object key '"
                     + key

src/main/java/org/mybatis/caches/memcached/StringUtils.java

@@ -0,0 +1,76 @@
+package org.mybatis.caches.memcached;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * Got from https://github.com/raykrueger/hibernate-memcached
+ * 
+ * @author Ray Krueger
+ */
+public class StringUtils {
+
+    private static final char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+
+    public static String join(Object[] array, String separator) {
+	if (array == null) {
+	    return null;
+	}
+	int arraySize = array.length;
+	StringBuilder buffer = new StringBuilder();
+
+	for (int i = 0; i < arraySize; i++) {
+	    if (i > 0) {
+		buffer.append(separator);
+	    }
+	    if (array[i] != null) {
+		buffer.append(array[i]);
+	    }
+	}
+	return buffer.toString();
+    }
+
+    public static String md5Hex(String data) {
+	if (data == null) {
+	    throw new IllegalArgumentException("data must not be null");
+	}
+
+	byte[] bytes = digest("MD5", data);
+
+	return toHexString(bytes);
+    }
+
+    public static String sha1Hex(String data) {
+	if (data == null) {
+	    throw new IllegalArgumentException("data must not be null");
+	}
+
+	byte[] bytes = digest("SHA1", data);
+
+	return toHexString(bytes);
+    }
+
+    private static String toHexString(byte[] bytes) {
+	int l = bytes.length;
+
+	char[] out = new char[l << 1];
+
+	for (int i = 0, j = 0; i < l; i++) {
+	    out[j++] = DIGITS[(0xF0 & bytes[i]) >>> 4];
+	    out[j++] = DIGITS[0x0F & bytes[i]];
+	}
+
+	return new String(out);
+    }
+
+    private static byte[] digest(String algorithm, String data) {
+	MessageDigest digest;
+	try {
+	    digest = MessageDigest.getInstance(algorithm);
+	} catch (NoSuchAlgorithmException e) {
+	    throw new RuntimeException(e);
+	}
+
+	return digest.digest(data.getBytes());
+    }
+}