/*
* $Id: Bean.java 768855 2009-04-27 02:09:35Z wesw $
*
* 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.
*/
package org.apache.struts2.components;
import java.io.Writer;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;
import com.opensymphony.xwork2.ObjectFactory;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.ClassLoaderUtil;
import com.opensymphony.xwork2.util.ValueStack;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import com.opensymphony.xwork2.util.reflection.ReflectionProvider;
/**
* <!-- START SNIPPET: javadoc -->
* <p>Instantiates a class that conforms to the JavaBeans specification. This tag has a body which can contain
* a number of {@link Param} elements to set any mutator methods on that class.</p>
* <p/>
* <p>If the var attribute is set on the BeanTag, it will place the instantiated bean into the
* stack's Context.</p>
* <p/>
* <!-- END SNIPPET: javadoc -->
*
*
* <!-- START SNIPPET: params -->
* <ul>
* <li>var - the stack's context name (if supplied) that the created bean will be store under</li>
* <li>name* - the class name of the bean to be instantiated (must respect JavaBean specification)</li>
* </ul>
* <!-- END SNIPPET: params -->
*
*
* <p>Examples:</p>
* <p/>
* <pre>
* <!-- START SNIPPET: examples -->
* <-- in freemarker form -->
* [@s.bean name="org.apache.struts2.example.counter.SimpleCounter" var="counter"]
* [s:param name="foo" value="BAR"/]
* The value of foo is : [s:property value="foo"/], when inside the bean tag.<br />
* [/s:bean]
*
* <-- in jsp form -->
* <s:bean name="org.apache.struts2.example.counter.SimpleCounter" var="counter">
* <s:param name="foo" value="BAR" />
* The value of foot is : <s:property value="foo"/>, when inside the bean tag <br />
* </s:bean>
* <!-- END SNIPPET: examples -->
* </pre>
* <p/>
*
* <!-- START SNIPPET: examplesdescription -->
* <p>This example instantiates a bean called SimpleCounter and sets the foo property (setFoo('BAR')). The
* SimpleCounter object is then pushed onto the Valuestack, which means that we can call its accessor methods (getFoo())
* with the Property tag and get their values.</p>
* <p/>
* <p>In the above example, the id has been set to a value of <i>counter</i>. This means that the SimpleCounter class
* will be placed into the stack's context. You can access the SimpleCounter class using a Struts tag:</p>
* <p/>
* <pre>
* <-- jsp form -->
* <s:property value="#counter" />
*
* <-- freemarker form -->
* [s:property value="#counter.foo"/]
* </pre>
* <p/>
* <p>In the property tag example, the <i>#</i> tells Ognl to search the context for the SimpleCounter class which has
* an id(key) of <i>counter</i></p>
* <!-- END SNIPPET: examplesdescription -->
*
* @see Param
*/
@StrutsTag(name="bean", tldTagClass="org.apache.struts2.views.jsp.BeanTag",
description="Instantiate a JavaBean and place it in the context")
public class Bean extends ContextBean {
protected static final Logger LOG = LoggerFactory.getLogger(Bean.class);
protected Object bean;
protected String name;
protected ObjectFactory objectFactory;
protected ReflectionProvider reflectionProvider;
public Bean(ValueStack stack) {
super(stack);
}
@Inject
public void setObjectFactory(ObjectFactory objectFactory) {
this.objectFactory = objectFactory;
}
@Inject
public void setReflectionProvider(ReflectionProvider prov) {
this.reflectionProvider = prov;
}
public boolean start(Writer writer) {
boolean result = super.start(writer);
ValueStack stack = getStack();
try {
String beanName = findString(name, "name", "Bean name is required. Example: com.acme.FooBean");
bean = objectFactory.buildBean(ClassLoaderUtil.loadClass(beanName, getClass()), stack.getContext());
} catch (Exception e) {
LOG.error("Could not instantiate bean", e);
return false;
}
// push bean on stack
stack.push(bean);
// store for reference later
putInContext(bean);
return result;
}
public boolean end(Writer writer, String body) {
ValueStack stack = getStack();
stack.pop();
return super.end(writer, body);
}
public void addParameter(String key, Object value) {
reflectionProvider.setProperty(key, value, bean, getStack().getContext());
}
@StrutsTagAttribute(description="The class name of the bean to be instantiated (must respect JavaBean specification)",
required=true)
public void setName(String name) {
this.name = name;
}
}
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