package org.apache.velocity.runtime.parser.node;
/*
* 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.reflect.InvocationTargetException;
import org.apache.commons.lang.StringUtils;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.RuntimeLogger;
import org.apache.velocity.runtime.log.Log;
import org.apache.velocity.runtime.log.RuntimeLoggerLog;
import org.apache.velocity.util.introspection.Introspector;
/**
* Returned the value of object property when executed.
*/
public class PropertyExecutor extends AbstractExecutor
{
private final Introspector introspector;
/**
* @param log
* @param introspector
* @param clazz
* @param property
* @since 1.5
*/
public PropertyExecutor(final Log log, final Introspector introspector,
final Class clazz, final String property)
{
this.log = log;
this.introspector = introspector;
// Don't allow passing in the empty string or null because
// it will either fail with a StringIndexOutOfBounds error
// or the introspector will get confused.
if (StringUtils.isNotEmpty(property))
{
discover(clazz, property);
}
}
/**
* @param r
* @param introspector
* @param clazz
* @param property
* @deprecated RuntimeLogger is deprecated. Use the other constructor.
*/
public PropertyExecutor(final RuntimeLogger r, final Introspector introspector,
final Class clazz, final String property)
{
this(new RuntimeLoggerLog(r), introspector, clazz, property);
}
/**
* @return The current introspector.
* @since 1.5
*/
protected Introspector getIntrospector()
{
return this.introspector;
}
/**
* @param clazz
* @param property
*/
protected void discover(final Class clazz, final String property)
{
/*
* this is gross and linear, but it keeps it straightforward.
*/
try
{
Object [] params = {};
StringBuffer sb = new StringBuffer("get");
sb.append(property);
setMethod(introspector.getMethod(clazz, sb.toString(), params));
if (!isAlive())
{
/*
* now the convenience, flip the 1st character
*/
char c = sb.charAt(3);
if (Character.isLowerCase(c))
{
sb.setCharAt(3, Character.toUpperCase(c));
}
else
{
sb.setCharAt(3, Character.toLowerCase(c));
}
setMethod(introspector.getMethod(clazz, sb.toString(), params));
}
}
/**
* pass through application level runtime exceptions
*/
catch( RuntimeException e )
{
throw e;
}
catch(Exception e)
{
String msg = "Exception while looking for property getter for '" + property;
log.error(msg, e);
throw new VelocityException(msg, e);
}
}
/**
* @see org.apache.velocity.runtime.parser.node.AbstractExecutor#execute(java.lang.Object)
*/
public Object execute(Object o)
throws IllegalAccessException, InvocationTargetException
{
return isAlive() ? getMethod().invoke(o, ((Object []) null)) : null;
}
}
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