/*
* $Id: SizeTag.java 471754 2006-11-06 14:55:09Z husted $
*
* 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.struts.taglib.bean;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Map;
/**
* Define a scripting variable that will contain the number of elements found
* in a specified array, Collection, or Map.
*
* @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
* $
*/
public class SizeTag extends TagSupport {
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources(
"org.apache.struts.taglib.bean.LocalStrings");
// ------------------------------------------------------------- Properties
/**
* The actual collection to be counted.
*/
protected Object collection = null;
/**
* The name of the scripting variable that will be exposed as a page scope
* attribute.
*/
protected String id = null;
/**
* The name of the bean owning the property to be counted.
*/
protected String name = null;
/**
* The name of the property to be retrieved.
*/
protected String property = null;
/**
* The scope within which to search for the specified bean.
*/
protected String scope = null;
public Object getCollection() {
return (this.collection);
}
public void setCollection(Object collection) {
this.collection = collection;
}
public String getId() {
return (this.id);
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return (this.name);
}
public void setName(String name) {
this.name = name;
}
public String getProperty() {
return (this.property);
}
public void setProperty(String property) {
this.property = property;
}
public String getScope() {
return (this.scope);
}
public void setScope(String scope) {
this.scope = scope;
}
// --------------------------------------------------------- Public Methods
/**
* Retrieve the required property and expose it as a scripting variable.
*
* @throws JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
// Retrieve the required property value
Object value = this.collection;
if (value == null) {
if (name == null) {
// Must specify either a collection attribute or a name
// attribute.
JspException e =
new JspException(messages.getMessage(
"size.noCollectionOrName"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
value =
TagUtils.getInstance().lookup(pageContext, name, property, scope);
}
// Identify the number of elements, based on the collection type
int size = 0;
if (value == null) {
JspException e =
new JspException(messages.getMessage("size.collection"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
} else if (value.getClass().isArray()) {
size = Array.getLength(value);
} else if (value instanceof Collection) {
size = ((Collection) value).size();
} else if (value instanceof Map) {
size = ((Map) value).size();
} else {
JspException e =
new JspException(messages.getMessage("size.collection"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
// Expose this size as a scripting variable
pageContext.setAttribute(this.id, new Integer(size),
PageContext.PAGE_SCOPE);
return (SKIP_BODY);
}
/**
* Release all allocated resources.
*/
public void release() {
super.release();
collection = null;
id = null;
name = null;
property = null;
scope = null;
}
}