Struts2:更新“对象列表"的值在地图内

  
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问题描述

There is an object ObjectA which has a list of ObjectB. There is a TreeMap inside the ObjectB. This TreeMap has a String as key and a List of another object ObjectC as value. This TreeMap and the list inside has been displayed on the jsp using the s:iterator and s:textfield and it is being displayed correctly. i.e. the "values" inside the s:textfield are correct. Now, the problem arises when the textfield is modified. How do we capture the modified values inside ObjectC in the action class? With the code given here, the key ("Key1") comes in the action but the value is null.

Java Code

public class ObjectA implements Serializable {
private Integer attr1;
private List<ObjectB> objB;
//...getters and setters....
public class ObjectB implements Serializable {
private Integer attr11;
private TreeMap<String,List<ObjectC>> allPlainFields;
// ...getters and setters....
public class ObjectC implements Serializable {
private Integer attr111;
public String attr112;
// ...getters and setters....

JSP Code

<s:iterator value="objA.objB" var="currentObjB" status="currentGroupStatus">

  <s:iterator value="#currentObjB.allPlainFields" var="parentMap" status="headerStatus">
     <s:iterator value="#parentMap.value" var="fieldList" status="fieldStatus">

       <s:textfield  name="objA.objB[%{#currentGroupStatus.index}].allPlainFields['%{#parentMap.key}'][%{#fieldStatus.index}].attr112"/>


</s:iterator>                       

 </s:iterator>

HTML rendered: <input type="text" id="review-act1_objA_objB_0__allPlainFields_'Key1'__6__attr112" value="Correct Value" name="objA.objB[0].allPlainFields['Key1'][0].attr112">

The object structure in the "VAriables" view of eclipse shows:

objA    Object A  (id=955)  
objB    ArrayList<E>  (id=966)  
    elementData Object[10]  (id=967)    
        [0] ObjectB  (id=968)   
            allPlainFields  TreeMap<K,V>  (id=972)  
                comparator  null    
                descendingMap   null    
                entrySet    TreeMap$EntrySet  (id=979)  
                keySet  null    
                modCount    1   
                navigableKeySet null    
                root    TreeMap$Entry<K,V>  (id=980)    
                size    1   
                values  null    

        [1] ObjectB  (id=969)   
        [2] ObjectB  (id=970)   
        [3] ObjectB  (id=971)   
        [4] null    
        [5] null    
        [6] null    
        [7] null    
        [8] null    
        [9] null    
    modCount    4   
    size    4

****In the Eclipse "Variables" view, the value for allPlainFields is**:** {Key1=}

EDIT(27-Feb-2013):

Tried this but didn't work. The values appear on jsp but when submitted, they don't come in action:

In Action class:

private TreeMap<String,ObjectCList> testTreeMap = new TreeMap<String,ObjectCList>();
//get,set and setting two keys in map "mykey1" and "mykey2"

In ObjectCList class:

private ArrayList<ObjectC> paramMdlList;
 //default constructor, get, set

In JSP:

<s:form id="test-map" method="post">
<s:iterator value="testTreeMap" var="pMap" status="hStatus">
     <li><label><s:property value="%{#pMap.key}" /></label> 
        <s:iterator value="%{#pMap.value.paramMdlList}" var="pList" status="innerStatus">
            <s:textfield name="testTreeMap['%{#pMap.key}'].paramMdlList[%{#innerStatus.index}].attr111"/>
            <s:textfield name="testTreeMap['%{#pMap.key}'].paramMdlList[%{#innerStatus.index}].attr112"/> 

        </s:iterator>


    </li>

</s:iterator>
<s:submit value=" " type='button' id="btnh1" action="saveTreeMap">
            <span>Save TreeMap</span>
</s:submit>
</s:form>

When the form is submitted, updateTreeMap method of the action is called. The map is printed as mentioned here :

public String updateTreeMap(){

    for (Map.Entry<String, ObjectCList> entry : testTreeMap.entrySet())
    {
        System.out.println(entry.getKey() + "/" + entry.getValue());
    }

    return SUCCESS;

}

What is "printed" : mykey1/ mykey2/ i.e. null values

The screen below shows values coming in jsp

解决方案

According to your latest update. If you are using TreeMap Struts2 cannot correctly determine type of elements inside it. Change declaration of testTreeMap from TreeMap to Map.

private Map<String,ObjectCList> testTreeMap = new TreeMap<String,ObjectCList>();

Or annotate testTreeMap with com.opensymphony.xwork2.util.Element annotation to tell Struts2 what type are elements inside map.

@Element(value = ObjectCList.class)
private TreeMap<String,ObjectCList> testTreeMap = new TreeMap<String,ObjectCList>();

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