/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.log4j.joran.action;
import org.apache.log4j.config.PropertySetter;
import org.apache.log4j.helpers.Loader;
import org.apache.log4j.helpers.Option;
import org.apache.log4j.joran.action.ImplicitAction;
import org.apache.log4j.joran.spi.ExecutionContext;
import org.apache.log4j.joran.spi.Pattern;
import org.apache.log4j.spi.Component;
import org.apache.log4j.spi.ErrorItem;
import org.apache.log4j.spi.OptionHandler;
import org.xml.sax.Attributes;
import java.util.Stack;
/**
* @author Ceki Gülcü
*
*/
public class NestComponentIA extends ImplicitAction {
// actionDataStack contains ActionData instances
// We use a stack of ActionData objects in order to support nested
// elements which are handled by the same NestComponentIA instance.
// We push a ActionData instance in the isApplicable method (if the
// action is applicable) and pop it in the end() method.
// The XML well-formedness property will guarantee that a push will eventually
// be followed by the corresponding pop.
Stack actionDataStack = new Stack();
public boolean isApplicable(
Pattern pattern, Attributes attributes, ExecutionContext ec) {
//LogLog.debug("in NestComponentIA.isApplicable <" + pattern + ">");
String nestedElementTagName = pattern.peekLast();
Object o = ec.peekObject();
PropertySetter parentBean = new PropertySetter(o);
int containmentType = parentBean.canContainComponent(nestedElementTagName);
switch (containmentType) {
case PropertySetter.NOT_FOUND:
return false;
// we only push action data if NestComponentIA is applicable
case PropertySetter.AS_COLLECTION:
case PropertySetter.AS_PROPERTY:
ActionData ad = new ActionData(parentBean, containmentType);
actionDataStack.push(ad);
return true;
default:
ec.addError(
new ErrorItem(
"PropertySetter.canContainComponent returned " + containmentType));
return false;
}
}
public void begin(
ExecutionContext ec, String localName, Attributes attributes) {
//LogLog.debug("in NestComponentIA begin method");
// get the action data object pushed in isApplicable() method call
ActionData actionData = (ActionData) actionDataStack.peek();
String className = attributes.getValue(CLASS_ATTRIBUTE);
// perform variable name substitution
className = ec.subst(className);
if (Option.isEmpty(className)) {
actionData.inError = true;
String errMsg = "No class name attribute in <" + localName + ">";
getLogger().error(errMsg);
ec.addError(new ErrorItem(errMsg));
return;
}
try {
getLogger().debug(
"About to instantiate component <{}> of type [{}]", localName,
className);
actionData.nestedComponent = Loader.loadClass(className).newInstance();
// pass along the repository
if(actionData.nestedComponent instanceof Component) {
((Component) actionData.nestedComponent).setLoggerRepository(this.repository);
}
getLogger().debug(
"Pushing component <{}> on top of the object stack.", localName);
ec.pushObject(actionData.nestedComponent);
} catch (Exception oops) {
actionData.inError = true;
String msg = "Could not create component <" + localName + ">.";
getLogger().error(msg, oops);
ec.addError(new ErrorItem(msg));
}
}
public void end(ExecutionContext ec, String tagName) {
getLogger().debug("entering end method");
// pop the action data object pushed in isApplicable() method call
// we assume that each this begin
ActionData actionData = (ActionData) actionDataStack.pop();
if (actionData.inError) {
return;
}
if (actionData.nestedComponent instanceof OptionHandler) {
((OptionHandler) actionData.nestedComponent).activateOptions();
}
Object o = ec.peekObject();
if (o != actionData.nestedComponent) {
getLogger().warn(
"The object on the top the of the stack is not the component pushed earlier.");
} else {
getLogger().debug("Removing component from the object stack");
ec.popObject();
// Now let us attach the component
switch (actionData.containmentType) {
case PropertySetter.AS_PROPERTY:
getLogger().debug(
"Setting [{}] to parent of type [{}]", tagName,
actionData.parentBean.getObjClass());
actionData.parentBean.setComponent(
tagName, actionData.nestedComponent);
break;
case PropertySetter.AS_COLLECTION:
getLogger().debug(
"Adding [{}] to parent of type [{}]", tagName,
actionData.parentBean.getObjClass());
actionData.parentBean.addComponent(
tagName, actionData.nestedComponent);
break;
}
}
}
public void finish(ExecutionContext ec) {
}
}
class ActionData {
PropertySetter parentBean;
Object nestedComponent;
int containmentType;
boolean inError;
ActionData(PropertySetter parentBean, int containmentType) {
this.parentBean = parentBean;
this.containmentType = containmentType;
}
}