tomcat-cluster-redis-sessio.../src/main/java/tomcat/request/session/SerializationUtil.java

112 lines
3.0 KiB
Java

package tomcat.request.session;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.MessageDigest;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import org.apache.catalina.util.CustomObjectInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Tomcat clustering with Redis data-cache implementation.
*
* Session serialization utility.
*
* @author Ranjith Manickam
* @since 2.0
*/
public class SerializationUtil {
private ClassLoader loader;
private Log log = LogFactory.getLog(SerializationUtil.class);
/**
* To set class loader
*
* @param loader
*/
public void setClassLoader(ClassLoader loader) {
this.loader = loader;
}
/**
* To get session attributes hash code
*
* @param session
* @return
* @throws IOException
*/
public byte[] getSessionAttributesHashCode(Session session) throws IOException {
byte[] serialized = null;
Map<String, Object> attributes = new HashMap<String, Object>();
for (Enumeration<String> enumerator = session.getAttributeNames(); enumerator.hasMoreElements();) {
String key = enumerator.nextElement();
attributes.put(key, session.getAttribute(key));
}
try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(bos));) {
oos.writeUnshared(attributes);
oos.flush();
serialized = bos.toByteArray();
}
MessageDigest digester = null;
try {
digester = MessageDigest.getInstance("MD5");
} catch (Exception ex) {
log.error("Unable to get MessageDigest instance for MD5", ex);
}
return digester.digest(serialized);
}
/**
* To serialize session object
*
* @param session
* @param metadata
* @return
* @throws IOException
*/
public byte[] serializeSessionData(Session session, SessionMetadata metadata) throws IOException {
byte[] serialized = null;
try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(bos));) {
oos.writeObject(metadata);
session.writeObjectData(oos);
oos.flush();
serialized = bos.toByteArray();
}
return serialized;
}
/**
* To de-serialize session object
*
* @param data
* @param session
* @param metadata
* @throws IOException
* @throws ClassNotFoundException
*/
public void deserializeSessionData(byte[] data, Session session, SessionMetadata metadata)
throws IOException, ClassNotFoundException {
try (BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(data));
ObjectInputStream ois = new CustomObjectInputStream(bis, this.loader);) {
SessionMetadata serializedMetadata = (SessionMetadata) ois.readObject();
metadata.copyFieldsFrom(serializedMetadata);
session.readObjectData(ois);
}
}
}