org.apache.struts2.components.AppendIterator Maven / Gradle / Ivy
/*
* 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 com.opensymphony.xwork2.util.ValueStack;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.struts2.components.Param.UnnamedParametric;
import org.apache.struts2.util.AppendIteratorFilter;
import org.apache.struts2.util.MakeIterator;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
*
* Component for AppendIteratorTag, which jobs is to append iterators to form an
* appended iterator whereby entries goes from one iterator to another after each
* respective iterator is exhausted of entries.
*
* For example, if there are 3 iterator appended (each iterator has 3 entries),
* the following will be how the appended iterator entries will be arranged:
*
*
* - First Entry of the First Iterator
* - Second Entry of the First Iterator
* - Third Entry of the First Iterator
* - First Entry of the Second Iterator
* - Second Entry of the Second Iterator
* - Third Entry of the Second Iterator
* - First Entry of the Third Iterator
* - Second Entry of the Third Iterator
* - Third Entry of the Third ITerator
*
*
*
*
*
* - var (String) - the name of which if supplied will have the resultant
* appended iterator stored under in the stack's context
*
*
*
*
*
* public class AppendIteratorTagAction extends ActionSupport {
*
* private List myList1;
* private List myList2;
* private List myList3;
*
*
* public String execute() throws Exception {
*
* myList1 = new ArrayList();
* myList1.add("1");
* myList1.add("2");
* myList1.add("3");
*
* myList2 = new ArrayList();
* myList2.add("a");
* myList2.add("b");
* myList2.add("c");
*
* myList3 = new ArrayList();
* myList3.add("A");
* myList3.add("B");
* myList3.add("C");
*
* return "done";
* }
*
* public List getMyList1() { return myList1; }
* public List getMyList2() { return myList2; }
* public List getMyList3() { return myList3; }
*}
*
*
*
* <s:append var="myAppendIterator">
* <s:param value="%{myList1}" />
* <s:param value="%{myList2}" />
* <s:param value="%{myList3}" />
* </s:append>
* <s:iterator value="%{#myAppendIterator}">
* <s:property />
* </s:iterator>
*
*
*
* @see org.apache.struts2.util.AppendIteratorFilter
* @see org.apache.struts2.views.jsp.iterator.AppendIteratorTag
*
*/
@StrutsTag(name="append", tldTagClass="org.apache.struts2.views.jsp.iterator.AppendIteratorTag", description="Append the values of a list of iterators to one iterator")
public class AppendIterator extends ContextBean implements UnnamedParametric {
private static final Logger LOG = LogManager.getLogger(AppendIterator.class);
private AppendIteratorFilter appendIteratorFilter= null;
private List _parameters;
public AppendIterator(ValueStack stack) {
super(stack);
}
public boolean start(Writer writer) {
_parameters = new ArrayList();
appendIteratorFilter = new AppendIteratorFilter();
return super.start(writer);
}
public boolean end(Writer writer, String body) {
for (Iterator paramEntries = _parameters.iterator(); paramEntries.hasNext(); ) {
Object iteratorEntryObj = paramEntries.next();
if (! MakeIterator.isIterable(iteratorEntryObj)) {
LOG.warn("param with value resolved as {} cannot be make as iterator, it will be ignored and hence will not appear in the merged iterator", iteratorEntryObj);
continue;
}
appendIteratorFilter.setSource(MakeIterator.convert(iteratorEntryObj));
}
appendIteratorFilter.execute();
putInContext(appendIteratorFilter);
appendIteratorFilter = null;
return super.end(writer, body);
}
// UnnamedParametric implementation --------------------------------------
public void addParameter(Object value) {
_parameters.add(value);
}
@StrutsTagAttribute(description="The name of which if supplied will have the resultant appended iterator stored under in the stack's context")
public void setVar(String var) {
super.setVar(var);
}
}