package org.jboss.weld.environment.tomcat;
import static org.jboss.weld.environment.servlet.util.Reflections.findDeclaredField;
import static org.jboss.weld.environment.servlet.util.Reflections.findDeclaredMethod;
import static org.jboss.weld.environment.servlet.util.Reflections.getFieldValue;
import static org.jboss.weld.environment.servlet.util.Reflections.invokeMethod;
import static org.jboss.weld.environment.servlet.util.Reflections.setFieldValue;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import javax.naming.NamingException;
import javax.servlet.ServletContext;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.ApplicationContextFacade;
import org.apache.catalina.core.StandardContext;
import org.apache.tomcat.InstanceManager;
import org.jboss.weld.environment.servlet.logging.TomcatLogger;
import org.jboss.weld.manager.api.WeldManager;
/**
* Forwards all calls in turn to two delegates: first to InstanceManager, then
* to WeldInstanceManager
*
* @author <a href="mailto:matija.mazi@gmail.com">Matija Mazi</a>
*/
public class WeldForwardingInstanceManager extends ForwardingInstanceManager {
private static final String INSTANCE_MANAGER_FIELD_NAME = "instanceManager";
private final InstanceManager firstProcessor;
private final InstanceManager secondProcessor;
public WeldForwardingInstanceManager(InstanceManager originalAnnotationProcessor, InstanceManager weldProcessor) {
this.firstProcessor = originalAnnotationProcessor;
this.secondProcessor = weldProcessor;
}
@Override
protected InstanceManager delegate() {
return firstProcessor;
}
@Override
public void destroyInstance(Object o) throws IllegalAccessException, InvocationTargetException {
super.destroyInstance(o);
secondProcessor.destroyInstance(o);
}
@Override
public void newInstance(Object o) throws IllegalAccessException, InvocationTargetException, NamingException {
super.newInstance(o);
secondProcessor.newInstance(o);
}
@Override
public Object newInstance(String fqcn, ClassLoader classLoader) throws IllegalAccessException, InvocationTargetException, NamingException, InstantiationException, ClassNotFoundException {
Object a = super.newInstance(fqcn, classLoader);
secondProcessor.newInstance(a);
return a;
}
@Override
public Object newInstance(String fqcn) throws IllegalAccessException, InvocationTargetException, NamingException, InstantiationException, ClassNotFoundException {
Object a = super.newInstance(fqcn);
secondProcessor.newInstance(a);
return a;
}
@Override
public Object newInstance(Class<?> clazz) throws IllegalAccessException, InvocationTargetException, NamingException, InstantiationException {
Object a = super.newInstance(clazz);
secondProcessor.newInstance(a);
return a;
}
public static void replaceInstanceManager(ServletContext context, WeldManager manager) {
StandardContext stdContext = getStandardContext(context);
setInstanceManager(stdContext, createInstance(manager, stdContext));
}
private static WeldForwardingInstanceManager createInstance(WeldManager manager, StandardContext stdContext) {
try {
InstanceManager weldProcessor = new WeldInstanceManager(manager);
return new WeldForwardingInstanceManager(getInstanceManager(stdContext), weldProcessor);
} catch (Exception e) {
throw TomcatLogger.LOG.cannotCreatWeldForwardingAnnotationProcessor(e);
}
}
private static StandardContext getStandardContext(ServletContext context) {
try {
// Hack into Tomcat to replace the InstanceManager using
// reflection to access private fields
ApplicationContext appContext = (ApplicationContext) getContextFieldValue((ApplicationContextFacade) context, ApplicationContextFacade.class);
return (StandardContext) getContextFieldValue(appContext, ApplicationContext.class);
} catch (Exception e) {
throw TomcatLogger.LOG.cannotGetStandardContext(e);
}
}
private static <E> Object getContextFieldValue(E obj, Class<E> clazz) throws NoSuchFieldException, IllegalAccessException {
Field f = clazz.getDeclaredField("context");
f.setAccessible(true);
return f.get(obj);
}
public static void restoreInstanceManager(ServletContext context) {
StandardContext stdContext = getStandardContext(context);
InstanceManager im = getInstanceManager(stdContext);
if (im instanceof WeldForwardingInstanceManager) {
setInstanceManager(stdContext, ((WeldForwardingInstanceManager) im).firstProcessor);
}
}
private static InstanceManager getInstanceManager(StandardContext stdContext) {
Method method = findDeclaredMethod(stdContext.getClass(), "getInstanceManager");
if (method != null) {
return invokeMethod(method, InstanceManager.class, stdContext);
}
Field field = findDeclaredField(stdContext.getClass(), INSTANCE_MANAGER_FIELD_NAME);
if (field != null) {
return getFieldValue(field, stdContext, InstanceManager.class);
}
throw TomcatLogger.LOG.neitherFieldNorSetterFound();
}
private static void setInstanceManager(StandardContext stdContext, InstanceManager instanceManager) {
Method method = findDeclaredMethod(stdContext.getClass(), "setInstanceManager", InstanceManager.class);
if (method != null) {
invokeMethod(method, void.class, stdContext, instanceManager);
return;
}
Field field = findDeclaredField(stdContext.getClass(), INSTANCE_MANAGER_FIELD_NAME);
if (field != null) {
setFieldValue(field, stdContext, instanceManager);
return;
}
throw TomcatLogger.LOG.neitherFieldNorSetterFound();
}
}