/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, version 2 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/gpl-2.0.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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 General Public License for more details.
*
*
* Copyright 2006 - 2016 Pentaho Corporation. All rights reserved.
*/
package org.pentaho.platform.engine.core.system.objfac.spring;
import org.pentaho.platform.api.engine.IPentahoObjectReference;
import org.pentaho.platform.api.engine.ISystemConfig;
import org.pentaho.platform.api.engine.ObjectFactoryException;
import org.pentaho.platform.engine.core.system.PentahoSessionHolder;
import org.pentaho.platform.engine.core.system.PentahoSystem;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.FactoryBean;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.List;
import java.util.Map;
/**
* Obtains a reference to the requested bean from the PentahoSystem
* <p/>
* {@code} <pen:bean class="com.foo.Clazz"/> {@code}
* <p/>
* User: nbaker Date: 3/2/13
*/
public class BeanBuilder implements FactoryBean {
private String type;
private Map<String, String> attributes;
private static ThreadLocal<BeanBuilder> resolvingBean = new ThreadLocal<BeanBuilder>();
private static Logger log = LoggerFactory.getLogger( BeanBuilder.class );
private Integer dampeningTimeout = null;
/*
* (non-Javadoc)
*
* @see org.springframework.beans.factory.FactoryBean#getObject()
*/
public Object getObject() {
try {
if ( resolvingBean.get() == this ) {
log.warn( "Circular Reference detected in bean creation ( "
+ type
+ " : "
+ attributes
+ "). Very likely a published "
+ "pentaho bean is resolving itself. Ensure that the published attributes do not match that of the Pentaho "
+ "bean query. The system will attempt to find the next highest available bean, but at a performance "
+ "penilty" );
// attempt to find a lower priority bean for them
Class cls = getClass().getClassLoader().loadClass( type.trim() );
resolvingBean.set( this );
List<IPentahoObjectReference<?>> objectReferences =
PentahoSystem.getObjectFactory().getObjectReferences( cls, PentahoSessionHolder.getSession(), attributes );
resolvingBean.set( null );
if ( objectReferences.size() > 1 ) {
// we have more than one, return the second highest
return objectReferences.get( 1 ).getObject();
} else {
// there's only one bean, this is a fatal situation
throw new IllegalStateException( "Fatal Circular reference in Pentaho Bean ( " + type + " : " + attributes
+ ")" );
}
} else {
final Class cls = getClass().getClassLoader().loadClass( type.trim() );
resolvingBean.set( this );
Object val = null;
IPentahoObjectReference objectReference =
PentahoSystem.getObjectFactory().getObjectReference( cls, PentahoSessionHolder.getSession(),
attributes );
if ( objectReference != null ) {
val = objectReference.getObject();
}
resolvingBean.set( null );
if ( val == null ) {
log.debug( "No object was found to satisfy pen:bean request [" + type + " : " + attributes + "]" );
final int f_dampeningTimeout = getDampeningTimeout();
// send back a proxy
if ( cls.isInterface() && dampeningTimeout > -1 ) {
log.debug( "Request bean which wasn't found is interface-based. Instantiating a Proxy dampener" );
val = Proxy.newProxyInstance( cls.getClassLoader(), new Class[] { cls }, new InvocationHandler() {
String lock = "lock_" + getClass().getName(); // class name to prevent locking somewhere else by the same string
Object target;
Thread watcher;
boolean dead = false;
private void startWatcherThread( final int millis ) {
watcher = new Thread( new Runnable() {
@Override public void run() {
int countdown = millis;
while ( countdown > 0 ) {
IPentahoObjectReference objectReference;
try {
objectReference =
PentahoSystem.getObjectFactory().getObjectReference( cls, PentahoSessionHolder.getSession(),
attributes );
if ( objectReference != null ) {
target = objectReference.getObject();
}
} catch ( ObjectFactoryException e ) {
log.debug( "Error fetching from PentahoSystem", e );
}
if ( target != null ) {
synchronized ( lock ) {
lock.notifyAll();
}
return;
}
countdown -= 100;
}
dead = true;
}
} );
watcher.start();
}
@Override public Object invoke( Object proxy, Method method, Object[] args ) throws Throwable {
if ( target == null && f_dampeningTimeout > 0 ) {
synchronized ( lock ) {
if ( watcher == null && !dead ) {
startWatcherThread( f_dampeningTimeout );
lock.wait( f_dampeningTimeout );
}
}
}
if ( target == null ) {
// Last chance. If the attributes are empty, try a plain PentahoSystem.get() which will find bean's
// with the ID equal to the simple name of the class
if ( attributes.isEmpty() || ( attributes.size() == 1 && attributes.containsKey( "id" ) ) ) {
target = getFallbackBySimpleName( cls, attributes );
}
if ( target == null ) {
throw new IllegalStateException( "Target of Bean was never resolved: " + cls.getName() );
}
}
return method.invoke( target, args );
}
} );
} else if ( !cls.isInterface() && ( attributes.isEmpty() || ( attributes.size() == 1 && attributes.containsKey( "id" ) ) ) ) {
val = getFallbackBySimpleName( cls, attributes );
}
}
return val;
}
} catch ( ClassNotFoundException e ) {
throw new RuntimeException( e );
} catch ( ObjectFactoryException e ) {
throw new RuntimeException( e );
}
}
private int getDampeningTimeout() {
if ( dampeningTimeout == null ) {
dampeningTimeout = 0;
ISystemConfig iSystemConfig = PentahoSystem.get( ISystemConfig.class );
if ( iSystemConfig != null ) {
String property = iSystemConfig.getProperty( "system.dampening-timeout" );
if ( property != null ) {
dampeningTimeout = Integer.valueOf( property );
}
}
}
return dampeningTimeout;
}
private Object getFallbackBySimpleName( Class clazz, Map<String, String> attributes ) {
Object lastChanceObject;
if ( attributes != null && attributes.containsKey( "id" ) ) {
lastChanceObject = PentahoSystem.get( clazz, attributes.get( "id" ), PentahoSessionHolder.getSession() );
} else {
lastChanceObject = PentahoSystem.get( clazz, PentahoSessionHolder.getSession() );
}
if ( lastChanceObject != null ) {
log.warn( "Target of <pen:bean class=\"" + clazz.getName()
+ "\"> was found using deprecated bean ID == class.getSimpleName() "
+ "fallback. The target bean with the id \"" + clazz.getSimpleName()
+ "\" should be published directly with <pen:publish>" );
}
return lastChanceObject;
}
/*
* (non-Javadoc)
*
* @see org.springframework.beans.factory.FactoryBean#getObjectType()
*/
public Class<?> getObjectType() {
return Object.class;
}
/*
* (non-Javadoc)
*
* @see org.springframework.beans.factory.FactoryBean#isSingleton()
*/
public boolean isSingleton() {
return true;
}
public String getType() {
return type;
}
public void setType( String type ) {
this.type = type;
}
public Map<String, String> getAttributes() {
return attributes;
}
public void setAttributes( Map<String, String> attributes ) {
this.attributes = attributes;
}
}