/*
* JBoss, Home of Professional Open Source
* Copyright 2006, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt 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.kernel.plugins.lazy;
import java.lang.reflect.Method;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import org.jboss.beans.info.spi.BeanInfo;
import org.jboss.beans.metadata.spi.BeanMetaData;
import org.jboss.dependency.spi.Controller;
import org.jboss.dependency.spi.ControllerContext;
import org.jboss.dependency.spi.ControllerMode;
import org.jboss.dependency.spi.ControllerState;
import org.jboss.kernel.Kernel;
import org.jboss.kernel.spi.config.KernelConfigurator;
import org.jboss.kernel.spi.dependency.KernelController;
import org.jboss.kernel.spi.dependency.KernelControllerContext;
import org.jboss.kernel.spi.lazy.LazyInitializer;
import org.jboss.kernel.spi.registry.KernelBus;
import org.jboss.metadata.spi.MetaData;
import org.jboss.util.JBossStringBuilder;
/**
* Abstract lazy initializer.
*
* @author <a href="mailto:ales.justin@jboss.com">Ales Justin</a>
*/
public abstract class AbstractLazyInitializer implements LazyInitializer
{
/**
* Abstract invoke handler.
*/
protected abstract class AbstractInvokeHandler
{
private String bean;
private KernelBus bus;
private Class<?> proxyClass;
private AtomicBoolean onDemandInitialized = new AtomicBoolean(false);
protected AbstractInvokeHandler(String bean, KernelBus bus, Class<?> proxyClass)
{
if (bean == null)
throw new IllegalArgumentException("Null bean name.");
this.bean = bean;
if (bus == null)
throw new IllegalArgumentException("Null Kernel bus.");
this.bus = bus;
this.proxyClass = proxyClass;
}
/**
* Excute invoke.
*
* @param proxy the proxy
* @param method the method
* @param args the arguments
* @return result
* @throws Throwable for any error
*/
protected Object executeInvoke(Object proxy, Method method, Object[] args) throws Throwable
{
String methodName = method.getName();
if ("hashCode".equals(methodName))
return System.identityHashCode(proxy);
if ("getClass".equalsIgnoreCase(methodName))
return proxyClass;
if ("equals".equals(methodName))
return proxy == args[0];
if ("toString".equals(methodName))
return bean + "Proxy";
if (onDemandInitialized.getAndSet(true) == false)
{
Kernel kernel = bus.getKernel();
KernelController controller = kernel.getController();
ControllerContext context = controller.getContext(bean, null);
if (context == null)
throw new IllegalArgumentException("No such context: " + bean);
if (ControllerState.INSTALLED.equals(context.getState()) == false)
{
ControllerMode mode = context.getMode();
if (ControllerMode.ON_DEMAND.equals(mode) || ControllerMode.MANUAL.equals(mode))
{
controller.change(context, ControllerState.INSTALLED);
}
}
if (ControllerState.INSTALLED.equals(context.getState()) == false)
throw new IllegalArgumentException("Bean " + bean + " cannot be fully installed: " + context);
}
if (isGetter(method))
{
return bus.get(bean, getLowerPropertyName(methodName));
}
else if (isSetter(method))
{
bus.set(bean, getLowerPropertyName(methodName), args[0]);
return null;
}
else
{
int length = args != null ? args.length : 0;
return bus.invoke(bean, methodName, args, new String[length]);
}
}
}
/**
* Is getter.
*
* @param minfo method
* @return true if metod is getter
*/
protected static boolean isGetter(Method minfo)
{
String name = minfo.getName();
Class<?> returnType = minfo.getReturnType();
Class<?>[] parameters = minfo.getParameterTypes();
if ((name.length() > 3 && name.startsWith("get")) || (name.length() > 2 && name.startsWith("is")))
{
// isBoolean() is not a getter for java.lang.Boolean
if (name.startsWith("is") && Boolean.TYPE.equals(returnType) == false)
return false;
if (parameters.length == 0 && Void.TYPE.equals(returnType) == false)
return true;
}
return false;
}
/**
* Is setter.
*
* @param minfo method
* @return true if method is setter
*/
protected static boolean isSetter(Method minfo)
{
String name = minfo.getName();
Class<?> returnType = minfo.getReturnType();
Class<?>[] parameters = minfo.getParameterTypes();
if ((name.length() > 3 && name.startsWith("set")))
{
if (parameters.length == 1 && Void.TYPE.equals(returnType))
return true;
}
return false;
}
/**
* Get lower property name.
*
* @param name the name
* @return lower case property name
*/
protected static String getLowerPropertyName(String name)
{
int start = name.startsWith("is") ? 2 : 3;
name = name.substring(start);
// If the second character is upper case then we don't make
// the first character lower case
if (name.length() > 1)
{
if (Character.isUpperCase(name.charAt(1)))
return name;
}
JBossStringBuilder buffer = new JBossStringBuilder(name.length());
buffer.append(Character.toLowerCase(name.charAt(0)));
if (name.length() > 1)
buffer.append(name.substring(1));
return buffer.toString();
}
/**
* Get kernel controller context.
*
* @param kernel the kernel
* @param bean bean name
* @return kernel controller context
* @throws IllegalArgumentException if context not found or not KernelControllerContext
*/
protected KernelControllerContext getKernelControllerContext(Kernel kernel, String bean)
{
Controller controller = kernel.getController();
ControllerContext context = controller.getContext(bean, null);
if (context == null)
throw new IllegalArgumentException("Should not be here, dependency failed, no such context: " + bean);
if (context instanceof KernelControllerContext == false)
throw new IllegalArgumentException("Context not KernelControllerContext: " + context);
return KernelControllerContext.class.cast(context);
}
/**
* Gte bean's class.
*
* @param context the kernel controller context
* @param configurator the configurator
* @param cl the classloader
* @return bean's class
* @throws Throwable for any error
*/
protected Class<?> getBeanClass(KernelControllerContext context, KernelConfigurator configurator, ClassLoader cl) throws Throwable
{
BeanMetaData bmd = context.getBeanMetaData();
Class<?> beanClass = null;
String beanClassName = bmd.getBean();
if (beanClassName != null)
beanClass = configurator.getClassInfo(beanClassName, cl).getType();
else if (context.getBeanInfo() != null)
beanClass = context.getBeanInfo().getClassInfo().getType();
if (beanClass == null)
throw new IllegalArgumentException("Not enough info to get bean class: " + context);
return beanClass;
}
/**
* Get bean info.
*
* @param kernel the kernel
* @param bean the bean name
* @return bean info instance
* @deprecated not used any more
*/
@Deprecated
protected BeanInfo getBeanInfo(Kernel kernel, String bean)
{
KernelControllerContext context = getKernelControllerContext(kernel, bean);
return context.getBeanInfo();
}
/**
* Get classes from class names.
*
* @param configurator the configurator
* @param classNames the class names
* @param cl classloader
* @return array of classes
* @throws Throwable for any error
*/
@SuppressWarnings("deprecation")
protected static Class<?>[] getClasses(KernelConfigurator configurator, Set<String> classNames, ClassLoader cl)
throws Throwable
{
Class<?>[] classes = new Class[classNames.size()];
int i = 0;
for (String className : classNames)
{
classes[i] = configurator.getClassInfo(className, cl).getType();
}
return classes;
}
public Object initializeProxy(Kernel kernel, String bean, boolean exposeClass, Set<String> interfaces, MetaData metaData) throws Throwable
{
return initializeProxy(kernel, bean, exposeClass, interfaces);
}
}