ActionEvent.java
package org.apache.turbine.modules;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.stream.Collectors;
import org.apache.commons.lang3.StringUtils;
import org.apache.fulcrum.parser.ParameterParser;
import org.apache.fulcrum.parser.ValueParser.URLCaseFolding;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.turbine.Turbine;
import org.apache.turbine.TurbineConstants;
import org.apache.turbine.annotation.AnnotationProcessor;
import org.apache.turbine.annotation.TurbineActionEvent;
import org.apache.turbine.annotation.TurbineConfiguration;
import org.apache.turbine.pipeline.PipelineData;
/**
* <p>
*
* This is an alternative to the Action class that allows you to do
* event based actions. Essentially, you label all your submit buttons
* with the prefix of "eventSubmit_" and the suffix of "methodName".
* For example, "eventSubmit_doDelete". Then any class that subclasses
* this class will get its "doDelete(PipelineData data)" method executed.
* If for any reason, it was not able to execute the method, it will
* fall back to executing the doPerform() method which is required to
* be implemented.
*
* <p>
*
* Limitations:
*
* <p>
*
* Because ParameterParser makes all the key values lowercase, we have
* to do some work to format the string into a method name. For
* example, a button name eventSubmit_doDelete gets converted into
* eventsubmit_dodelete. Thus, we need to form some sort of naming
* convention so that dodelete can be turned into doDelete.
*
* <p>
*
* Thus, the convention is this:
*
* <ul>
* <li>The variable name MUST have the prefix "eventSubmit_".</li>
* <li>The variable name after the prefix MUST begin with the letters
* "do".</li>
* <li>The first letter after the "do" will be capitalized and the
* rest will be lowercase</li>
* </ul>
*
* If you follow these conventions, then you should be ok with your
* method naming in your Action class.
*
* @author <a href="mailto:jon@latchkey.com">Jon S. Stevens </a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @author <a href="quintonm@bellsouth.net">Quinton McCombs</a>
* @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
* @version $Id$
*/
public abstract class ActionEvent implements Action
{
/** Logging */
protected Logger log = LogManager.getLogger(this.getClass());
/** The name of the button to look for. */
protected static final String BUTTON = "eventSubmit_";
/** The length of the button to look for. */
protected static final int BUTTON_LENGTH = BUTTON.length();
/** The default method. */
protected static final String DEFAULT_METHOD = "doPerform";
/** The prefix of the method name. */
protected static final String METHOD_NAME_PREFIX = "do";
/** The length of the method name. */
protected static final int METHOD_NAME_LENGTH = METHOD_NAME_PREFIX.length();
/** The length of the button to look for. */
protected static final int LENGTH = BUTTON.length();
/**
* If true, the eventSubmit_do<xxx> variable must contain
* a not null value to be executed.
*/
@TurbineConfiguration( TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_KEY )
private boolean submitValueKey = TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_DEFAULT;
/**
* If true, then exceptions raised in eventSubmit_do<xxx> methods
* as well as in doPerform methods are bubbled up to the Turbine
* servlet's handleException method.
*/
@TurbineConfiguration( TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP )
protected boolean bubbleUpException = TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP_DEFAULT;
/**
* Cache for the methods to invoke
*/
private ConcurrentMap<String, Method> methodCache = new ConcurrentHashMap<>();
/**
* Retrieve a method of the given name and signature. The value is cached.
*
* @param name the name of the method
* @param signature an array of classes forming the signature of the method
* @param pp ParameterParser for correct folding
*
* @return the method object
* @throws NoSuchMethodException if the method does not exist
*/
protected Method getMethod(String name, Class<?>[] signature, ParameterParser pp) throws NoSuchMethodException
{
String cacheKey =
Arrays.stream(signature)
.map(clazz -> ':' + clazz.getCanonicalName())
.collect(Collectors.joining("", name, ""));
Method method = this.methodCache.get(cacheKey);
if (method == null)
{
// Try annotations of public methods
Method[] methods = getClass().getMethods();
methodLoop:
for (Method m : methods)
{
Annotation[] annotations = AnnotationProcessor.getAnnotations(m);
for (Annotation a : annotations)
{
if (a instanceof TurbineActionEvent)
{
TurbineActionEvent tae = (TurbineActionEvent) a;
if (name.equals(pp.convert(tae.value()))
&& Arrays.equals(signature, m.getParameterTypes()))
{
method = m;
break methodLoop;
}
}
}
}
// Try legacy mode
if (method == null)
{
String tmp = name.toLowerCase().substring(METHOD_NAME_LENGTH);
method = getClass().getMethod(METHOD_NAME_PREFIX + StringUtils.capitalize(tmp), signature);
}
Method oldMethod = this.methodCache.putIfAbsent(cacheKey, method);
if (oldMethod != null)
{
method = oldMethod;
}
}
return method;
}
/**
* This overrides the default Action.doPerform() to execute the
* doEvent() method. If that fails, then it will execute the
* doPerform() method instead.
*
* @param pipelineData Turbine information.
* @throws Exception a generic exception.
*/
@Override
public void doPerform(PipelineData pipelineData)
throws Exception
{
ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
executeEvents(pp, new Class<?>[]{ PipelineData.class }, new Object[]{ pipelineData });
}
/**
* This method should be called to execute the event based system.
*
* @param pp the parameter parser
* @param signature the signature of the method to call
* @param parameters the parameters for the method to call
*
* @throws Exception a generic exception.
*/
protected void executeEvents(ParameterParser pp, Class<?>[] signature, Object[] parameters)
throws Exception
{
// Name of the button.
String theButton = null;
String button = pp.convert(BUTTON);
String key = null;
// Loop through and find the button.
for (String k : pp)
{
key = k;
if (key.startsWith(button))
{
if (considerKey(key, pp))
{
theButton = key;
break;
}
}
}
if (theButton == null)
{
theButton = BUTTON + DEFAULT_METHOD;
key = null;
}
theButton = formatString(theButton, pp);
Method method = null;
try
{
method = getMethod(theButton, signature, pp);
}
catch (NoSuchMethodException e)
{
method = getMethod(DEFAULT_METHOD, signature, pp);
}
finally
{
if (key != null)
{
pp.remove(key);
}
}
try
{
log.debug("Invoking {}", method);
method.invoke(this, parameters);
}
catch (InvocationTargetException ite)
{
Throwable t = ite.getTargetException();
if (bubbleUpException)
{
if (t instanceof Exception)
{
throw (Exception) t;
}
else
{
throw ite;
}
}
else
{
log.error("Invokation of {}", method, t);
}
}
}
/**
* This method does the conversion of the lowercase method name
* into the proper case.
*
* @param input The unconverted method name.
* @param pp The parameter parser (for correct folding)
* @return A string with the method name in the proper case.
*/
protected String formatString(String input, ParameterParser pp)
{
String tmp = input;
if (StringUtils.isNotEmpty(input))
{
tmp = input.toLowerCase();
// Chop off suffixes (for image type)
String methodName = (tmp.endsWith(".x") || tmp.endsWith(".y"))
? input.substring(0, input.length() - 2)
: input;
if (pp.getUrlFolding() == URLCaseFolding.NONE)
{
tmp = methodName.substring(BUTTON_LENGTH);
}
else
{
tmp = methodName.toLowerCase().substring(BUTTON_LENGTH);
}
}
return tmp;
}
/**
* Checks whether the selected key really is a valid event.
*
* @param key The selected key
* @param pp The parameter parser to look for the key value
*
* @return true if this key is really an ActionEvent Key
*/
protected boolean considerKey(String key, ParameterParser pp)
{
if (!submitValueKey)
{
log.debug("No Value required, accepting {}", key);
return true;
}
else
{
// If the action.eventsubmit.needsvalue key is true,
// events with a "0" or empty value are ignored.
// This can be used if you have multiple eventSubmit_do<xxx>
// fields in your form which are selected by client side code,
// e.g. JavaScript.
//
// If this key is unset or missing, nothing changes for the
// current behavior.
//
String keyValue = pp.getString(key);
log.debug("Key Value is {}", keyValue);
if (StringUtils.isEmpty(keyValue))
{
log.debug("Key is empty, rejecting {}", key);
return false;
}
try
{
if (Integer.parseInt(keyValue) != 0)
{
log.debug("Integer != 0, accepting {}", key);
return true;
}
}
catch (NumberFormatException nfe)
{
// Not a number. So it might be a
// normal Key like "continue" or "exit". Accept
// it.
log.debug("Not a number, accepting " + key);
return true;
}
}
log.debug("Rejecting {}", key);
return false;
}
}