Struts example source code file (RadioHandler.java)

This example Struts source code file (RadioHandler.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, boolean, io, ioexception, iterator, map, object, object, string, string, taggenerator, util, valuestack, valuestack

The Struts RadioHandler.java source code

/*
 * $Id: RadioHandler.java 1084872 2011-03-24 08:11:57Z 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.struts2.util.MakeIterator;
import org.apache.struts2.views.java.Attributes;
import org.apache.struts2.views.java.TagGenerator;
import org.apache.commons.lang.StringUtils;

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

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

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

        Object listObj = params.get("list");
        String listKey = (String) params.get("listKey");
        String listValue = (String) params.get("listValue");
        // NameValue is the value that is provided by the name property in the action
        Object nameValue = params.get("nameValue");
        int cnt = 0;

        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());

                //Namevalue needs to cast to a string from object. It's object because the 
                //Property can be defined as String or as Integer
                String itemNameValueStr;
                if (nameValue instanceof java.lang.Integer || nameValue instanceof java.lang.String)
                    itemNameValueStr = nameValue.toString();
                else
                    itemNameValueStr = null;

                //Checked value.  It's set to true if the nameValue (the value associated with the name which is typically set in 
                //the action is equal to the current key value.
                Boolean checked = itemKeyStr != null &&
                        itemNameValueStr != null &&
                        itemNameValueStr.equals(itemKeyStr);

                //Radio button section
                String id = params.get("id") + Integer.toString(cnt++);
                Attributes a = new Attributes();
                a.add("type", "radio")
                        .addDefaultToEmpty("name", params.get("name"))
                        .addIfTrue("checked", checked)
                        .addIfExists("value", itemKeyStr)
                        .addIfTrue("disabled", params.get("disabled"))
                        .addIfExists("tabindex", params.get("tabindex"))
                        .addIfExists("id", id);
                super.start("input", a);
                super.end("input");

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