How Does the Struts2 JSON Plugin Serialize Data Structures for AJAX Calls?
Dec 10, 2024 am 10:21 AMStruts2-JSON Plugin: Understanding Its Functionalities
The Struts2 JSON Plugin has a unique way of operating. It handles the serialization of actions into JSON, but only for certain elements:
- Non-transient properties
- Properties with getters
If you prefer to serialize only specific objects, the plugin provides a solution: the "root" attribute. This attribute allows you to specify the root object to be serialized using an OGNL expression.
<result type="json"> <param name="root"> objectToBeSerialized </param> </result>
The Action class should contain the following:
private CustomObject objectToBeSerialized; public CustomObject getObjectToBeSerialized() { return this.objectToBeSerialized; }
CustomObject can represent various data types, such as primitives, strings, arrays, etc.
By utilizing this method, you can return SUCCESS and ERROR like usual AJAX Struts2 actions without compromising framework conventions. Furthermore, you can access the serialized JSON object directly from the AJAX jQuery call's callback function.
Addressing Your Scenario
Assuming your data structure follows the pattern:
row1 [col1, col2], row2 [col1, col2], rowN [col1, col2]
You could employ the following approach:
1. Create a List of Custom Objects
public class MyRow implements Serializable { private String col1; private String col2; // Getters }
2. Modify the Action Class
public class PartAction implements Serializable { private List<MyRow> rows; // Getter public List<MyRow> getRows() { return this.rows; } public String finder() { rows = new ArrayList<MyRow>(); // Populate the list with data } }
3. Adjust Struts.xml
<result type="json" > <param name="root"> rows </param> </result>
4. AJAX Callback Function
var handledata = function(data) { $.each(data, function(index) { alert(data[index].col1); alert(data[index].col2); }); }
This approach allows you to serialize your desired data structure, making it accessible within your AJAX callback function.
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