/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ejb.plugins;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import javax.ejb.EJBObject;
import javax.ejb.Handle;
import javax.ejb.CreateException;
import javax.ejb.DuplicateKeyException;
import javax.ejb.EJBException;
import javax.ejb.FinderException;
import javax.ejb.RemoveException;
import org.jboss.ejb.Container;
import org.jboss.ejb.EntityContainer;
import org.jboss.ejb.EntityPersistenceStore;
import org.jboss.ejb.EntityEnterpriseContext;
import org.jboss.ejb.GenericEntityObjectFactory;
import org.jboss.metadata.EntityMetaData;
import org.jboss.system.server.ServerConfigLocator;
import org.jboss.system.ServiceMBeanSupport;
import org.jboss.util.file.FilenameSuffixFilter;
/**
* A file-based CMP entity bean persistence manager.
*
* <p>
* Reads and writes entity bean objects to files by using the
* standard Java serialization mechanism.
*
* <p>
* Enitiy state files are stored under:
* <tt><em>jboss-server-data-dir</em>/<em>storeDirectoryName</em>/<em>ejb-name</em></tt>.
*
* <p>
* Note, currently the name of the entity must be unique across the server, or
* unless the store directory is changed, to avoid data collisions.
*
* <p>
* jason: disabled because XDoclet can not handle \u0000 right now
* _@_jmx:mbean extends="org.jboss.system.ServiceMBean"
*
* @version <tt>$Revision: 81030 $</tt>
* @author <a href="mailto:rickard.oberg@telkel.com">Rickard Oberg</a>
* @author <a href="mailto:marc.fleury@telkel.com">Marc Fleury</a>
* @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
* <p><b>20010801 marc fleury:</b>
* <ul>
* <li>- insertion in cache upon create in now done in the instance interceptor
* </ul>
* <p><b>20011201 Dain Sundstrom:</b>
* <ul>
* <li>- added createBeanInstance and initEntity methods
* </ul>
* <p><b>20020525 Dain Sundstrom:</b>
* <ul>
* <li>- Replaced FinderResults with Collection
* <li>- Removed unused method loadEntities
* </ul>
*/
public class CMPFilePersistenceManager
extends ServiceMBeanSupport
implements EntityPersistenceStore /*, CMPFilePersistenceManagerMBean */
{
/** The default store directory name ("<tt>entities</tt>"). */
public static final String DEFAULT_STORE_DIRECTORY_NAME = "entities";
/** Our container. */
private EntityContainer con;
/**
* The sub-directory name under the server data directory where
* entity data is stored.
*
* @see #DEFAULT_STORE_DIRECTORY_NAME
*/
private String storeDirName = DEFAULT_STORE_DIRECTORY_NAME;
/** The base directory where bean state will be stored. */
private File storeDir;
/** A reference to the ID field for the entiy bean. */
private Field idField;
/** Optional isModified method used by storeEntity. */
private Method isModified;
/**
* Saves a reference to the {@link EntityContainer} for
* its bean type.
*
* @throws ClassCastException Container is not a EntityContainer.
*/
public void setContainer(final Container c)
{
con = (EntityContainer)c;
}
//
// jason: these properties are intended to be used when plugins/interceptors
// can take configuration values (need to update xml schema and processors).
//
/**
* Set the sub-directory name under the server data directory
* where entity data will be stored.
*
* <p>
* This value will be appened to the value of
* <tt><em>jboss-server-data-dir</em></tt>.
*
* <p>
* This value is only used during creation and will not dynamically
* change the store directory when set after the create step has finished.
*
* @jmx:managed-attribute
*
* @param dirName A sub-directory name.
*/
public void setStoreDirectoryName(final String dirName)
{
this.storeDirName = dirName;
}
/**
* Get the sub-directory name under the server data directory
* where entity data is stored.
*
* @jmx:managed-attibute
*
* @see #setStoreDirectoryName
*
* @return A sub-directory name.
*/
public String getStoreDirectoryName()
{
return storeDirName;
}
/**
* Returns the directory used to store entity state files.
*
* @jmx:managed-attibute
*
* @return The directory used to store entity state files.
*/
public File getStoreDirectory()
{
return storeDir;
}
protected void createService() throws Exception
{
// Initialize the dataStore
String ejbName = con.getBeanMetaData().getEjbName();
// Get the system data directory
File dir = ServerConfigLocator.locate().getServerDataDir();
//
// jason: may have to use a generated token from container config
// to determine a unique name for this config for the given
// entity name. it must persist through restarts though...
//
// Setup the reference to the entity data store directory
dir = new File(dir, storeDirName);
dir = new File(dir, ejbName);
storeDir = dir;
log.debug("Storing entity state for '" + ejbName + "' in: " + storeDir);
// if the directory does not exist then try to create it
if (!storeDir.exists()) {
if (!storeDir.mkdirs()) {
throw new IOException("Failed to create directory: " + storeDir);
}
}
// make sure we have a directory
if (!storeDir.isDirectory()) {
throw new IOException("File exists where directory expected: " + storeDir);
}
// make sure we can read and write to it
if (!storeDir.canWrite() || !storeDir.canRead()) {
throw new IOException("Directory must be readable and writable: " + storeDir);
}
// Get the ID field
idField = con.getBeanClass().getField("id");
log.debug("Using id field: " + idField);
// Lookup the isModified method if it exists
try
{
isModified = con.getBeanClass().getMethod("isModified", new Class[0]);
if (!isModified.getReturnType().equals(Boolean.TYPE)) {
isModified = null; // Has to have "boolean" as return type!
log.warn("Found isModified method, but return type is not boolean; ignoring");
}
else {
log.debug("Using isModified method: " + isModified);
}
}
catch (NoSuchMethodException ignored) {}
}
/**
* Try to remove the store directory, if we can't then ignore.
*/
protected void destroyService() throws Exception
{
storeDir.delete();
}
public Object createBeanClassInstance() throws Exception
{
return con.getBeanClass().newInstance();
}
/**
* Reset all attributes to default value
*
* <p>
* The EJB 1.1 specification is not entirely clear about this,
* the EJB 2.0 spec is, see page 169.
* Robustness is more important than raw speed for most server
* applications, and not resetting atrribute values result in
* *very* weird errors (old states re-appear in different instances and the
* developer thinks he's on drugs).
*/
public void initEntity(final EntityEnterpriseContext ctx)
{
// first get cmp metadata of this entity
Object instance = ctx.getInstance();
Class ejbClass = instance.getClass();
Field cmpField;
Class cmpFieldType;
EntityMetaData metaData = (EntityMetaData)con.getBeanMetaData();
Iterator i = metaData.getCMPFields();
while (i.hasNext())
{
// get the field declaration
try
{
cmpField = ejbClass.getField((String)i.next());
cmpFieldType = cmpField.getType();
// find the type of the field and reset it
// to the default value
if (cmpFieldType.equals(boolean.class))
{
cmpField.setBoolean(instance,false);
}
else if (cmpFieldType.equals(byte.class))
{
cmpField.setByte(instance,(byte)0);
}
else if (cmpFieldType.equals(int.class))
{
cmpField.setInt(instance,0);
}
else if (cmpFieldType.equals(long.class))
{
cmpField.setLong(instance,0L);
}
else if (cmpFieldType.equals(short.class))
{
cmpField.setShort(instance,(short)0);
}
else if (cmpFieldType.equals(char.class))
{
cmpField.setChar(instance,'\u0000');
}
else if (cmpFieldType.equals(double.class))
{
cmpField.setDouble(instance,0d);
}
else if (cmpFieldType.equals(float.class))
{
cmpField.setFloat(instance,0f);
}
else
{
cmpField.set(instance,null);
}
}
catch (NoSuchFieldException e)
{
// will be here with dependant value object's private attributes
// should not be a problem
}
catch (Exception e)
{
throw new EJBException(e);
}
}
}
public Object createEntity(final Method m,
final Object[] args,
final EntityEnterpriseContext ctx)
throws Exception
{
try {
Object id = idField.get(ctx.getInstance());
// Check exist
if (getFile(id).exists())
throw new DuplicateKeyException("Already exists: "+id);
// Store to file
storeEntity(id, ctx.getInstance());
return id;
}
catch (IllegalAccessException e)
{
throw new CreateException("Could not create entity: "+e);
}
}
public Object postCreateEntity(final Method m,
final Object[] args,
final EntityEnterpriseContext ctx)
throws Exception
{
return null;
}
public Object findEntity(final Method finderMethod,
final Object[] args,
final EntityEnterpriseContext ctx,
GenericEntityObjectFactory factory)
throws FinderException
{
if (finderMethod.getName().equals("findByPrimaryKey"))
{
if (!getFile(args[0]).exists())
throw new FinderException(args[0]+" does not exist");
return factory.getEntityEJBObject(args[0]);
}
return null;
}
public Collection findEntities(final Method finderMethod,
final Object[] args,
final EntityEnterpriseContext ctx,
GenericEntityObjectFactory factory)
{
if (finderMethod.getName().equals("findAll"))
{
String[] files = storeDir.list(new FilenameSuffixFilter(".ser"));
ArrayList result = new ArrayList(files.length);
for (int i = 0; i < files.length; i++) {
final String key = files[i].substring(0,files[i].length()-4);
result.add(factory.getEntityEJBObject(key));
}
return result;
}
else
{
// we only support find all
return Collections.EMPTY_LIST;
}
}
/**
* Non-operation.
*/
public void activateEntity(final EntityEnterpriseContext ctx)
{
// Nothing to do
}
public void loadEntity(final EntityEnterpriseContext ctx)
{
try
{
Object obj = ctx.getInstance();
// Read fields
ObjectInputStream in = new CMPObjectInputStream
(new BufferedInputStream(new FileInputStream(getFile(ctx.getId()))));
try {
Field[] f = obj.getClass().getFields();
for (int i = 0; i < f.length; i++)
{
f[i].set(obj, in.readObject());
}
}
finally {
in.close();
}
}
catch (Exception e)
{
throw new EJBException("Load failed", e);
}
}
private void storeEntity(Object id, Object obj)
{
try
{
// Store fields
ObjectOutputStream out = new CMPObjectOutputStream
(new BufferedOutputStream(new FileOutputStream(getFile(id))));
try {
Field[] f = obj.getClass().getFields();
for (int i = 0; i < f.length; i++)
{
out.writeObject(f[i].get(obj));
}
}
finally {
out.close();
}
}
catch (Exception e)
{
throw new EJBException("Store failed", e);
}
}
public boolean isStoreRequired(final EntityEnterpriseContext ctx) throws Exception
{
if (isModified == null)
{
return true;
}
Boolean modified = (Boolean) isModified.invoke(ctx.getInstance(), new Object[0]);
return modified.booleanValue();
}
public boolean isModified(EntityEnterpriseContext ctx) throws Exception
{
return isStoreRequired(ctx);
}
public void storeEntity(final EntityEnterpriseContext ctx)
{
storeEntity(ctx.getId(), ctx.getInstance());
}
/**
* Non-operation.
*/
public void passivateEntity(final EntityEnterpriseContext ctx)
{
// This plugin doesn't do anything specific
}
public void removeEntity(final EntityEnterpriseContext ctx)
throws RemoveException
{
// Remove file
File file = getFile(ctx.getId());
if (!file.delete()) {
throw new RemoveException("Could not remove file: " + file);
}
}
protected File getFile(final Object id)
{
return new File(storeDir, String.valueOf(id) + ".ser");
}
// Inner classes -------------------------------------------------
static class CMPObjectOutputStream
extends ObjectOutputStream
{
public CMPObjectOutputStream(final OutputStream out)
throws IOException
{
super(out);
enableReplaceObject(true);
}
protected Object replaceObject(final Object obj)
throws IOException
{
if (obj instanceof EJBObject)
return ((EJBObject)obj).getHandle();
return obj;
}
}
static class CMPObjectInputStream
extends ObjectInputStream
{
public CMPObjectInputStream(final InputStream in)
throws IOException
{
super(in);
enableResolveObject(true);
}
protected Object resolveObject(final Object obj)
throws IOException
{
if (obj instanceof Handle)
return ((Handle)obj).getEJBObject();
return obj;
}
}
}