Struts example source code file (CheckboxListHandler.java)

This example Struts source code file (CheckboxListHandler.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

abstracttaghandler, attributes, attributes, checkboxlisthandler, io, ioexception, iterator, map, object, object, string, string, taggenerator, util, valuestack, valuestack

The Struts CheckboxListHandler.java source code

/*
 * $Id: CheckboxListHandler.java 1081295 2011-03-14 09:54:09Z mcucchiara $
 *
 * 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.views.java.simple;

import com.opensymphony.xwork2.util.ValueStack;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.struts2.util.MakeIterator;
import org.apache.struts2.views.java.Attributes;
import org.apache.struts2.views.java.TagGenerator;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map;

public class CheckboxListHandler extends AbstractTagHandler implements TagGenerator {
    public void generate() throws IOException {

    	Map<String, Object> params = context.getParameters();

    	//Get parameters
        Object listObj = params.get("list");
        String listKey = (String) params.get("listKey");
        String listValue = (String) params.get("listValue");
        String name = (String) params.get("name");
        Object disabled = params.get("disabled");
        String id = (String) params.get("id");

        int cnt = 1;

        //This will interate through all lists
        ValueStack stack = this.context.getStack();
        if (listObj != null) {
            Iterator itt = MakeIterator.convert(listObj);
            while (itt.hasNext()) {
                Object item = itt.next();
                stack.push(item);

                //key
                Object itemKey = findValue(listKey != null ? listKey : "top");
                String itemKeyStr = StringUtils.defaultString(itemKey == null ? null : itemKey.toString());

                //value
                Object itemValue = findValue(listValue != null ? listValue : "top");
                String itemValueStr = StringUtils.defaultString(itemValue == null ? null : itemValue.toString());

                //Checkbox button section
                Attributes a = new Attributes();
                a.add("type", "checkbox")
	                .add("name", name)
	                .add("value", itemKeyStr)
	                .addIfTrue("checked", params.get("nameValue"))
	                .addIfTrue("readonly", params.get("readonly"))
	                .addIfTrue("disabled", disabled)
	                .addIfExists("tabindex", params.get("tabindex"))
	                .addIfExists("id", name + "-" + Integer.toString(cnt++));
		        start("input", a);
		        end("input");

                //Label section
                a = new Attributes();
                a.add("for",id)
                	.addIfExists("class", params.get("cssClass"))
                	.addIfExists("style", params.get("cssStyle"));
                super.start("label", a);
                if (StringUtils.isNotEmpty(itemValueStr))
                    characters(itemValueStr);
                super.end("label");

                //Hidden input section
                a = new Attributes();
                a.add("type", "hidden")
                        .add("id", "__multiselect_" + StringUtils.defaultString(StringEscapeUtils.escapeHtml(id)))
                        .add("name", "__multiselect_" + StringUtils.defaultString(StringEscapeUtils.escapeHtml(name)))
                        .add("value", "")
                        .addIfTrue("disabled", disabled);
                start("input", a);
                end("input");

                stack.pop();

            }
        }
    }
}