How to use jQuery to send JSON data to Action Struts2 class

Question

I have a problem sending data from jQuery to the struts2 action class. I saw a question: JSON JQuery for a Struts2 action , but I don't understand the solution very well.

Here is my problem:

The json array looks like this:

[{"id":"1","code":"111","name":"ddd"}, {"id":"2","code":"222","name":"sss"}, {"id":"3","code":"333","name":"eee"}] 

I want to send json data to struts2 action class. The jQuery code is as follows:

 var data = JSON.stringify(dataObj); $.ajax({ url: "Update", type: "post", data: data, dataType: 'json', contentType:"application/json;charset=utf-8", success : function(){ alert("You made it!"); } }); 

However, in the Chrome Development Tool, I saw data submitted to the server. But on the server side, I don't know how to get json data.

Act:

 public class Update extends ActionSupport{ private String data; public String getData(){ return data; } public void setData(String data){ this.data= data; } public String execute(){ System.out.println(data); return SUCCESS; } } 

So data is null.

I also tried using List to get JSON data. Changing the data type from String to List<Node> , it again failed. Perhaps because I do not quite understand the OGNL model that Struts2 uses.

Please help me. Thank you very much!

Answer 1

 {"id":"1","code":"111","name":"ddd"} 

Step 1. Create a bean / pojo to accumulate / encapsulate the above fields

 class MyBean{ String id,code,name; //getters & setters } 

Step 2. Change the action code to get a list of MyBeans

 public class Update extends ActionSupport{ private List<MyBean> data; //other code, getters & setters } 

Step 3. Configure the action to de-serialize JSON data and fill in the action fields (using json-plugin)

  <action name="Update" class="Update"> <interceptor-ref name="defaultStack"/> <interceptor-ref name="json"> <param name="enableSMD">true</param> </interceptor-ref> </action> 

Step 4: Make the necessary changes to the body of the ajax request sent to match the parameters / action fields

 var data = JSON.stringify(dataObj); $.ajax({ url: "Update", type: "post", data: "data:"+data, dataType: 'json', contentType:"application/json;charset=utf-8", success : function(){ alert("You made it!"); } }); 

The above code is not verified.

Answer 2

Hey. The problem is that you are directly sending an array of objects. So Struts2 does not know which method to call. Change json data as below. Then it will work.

 {"data":[{"id":"1","code":"111","name":"ddd"}, "id":"2","code":"222","name":"sss"}, {"id":"3","code":"333","name":"eee"}]} 

Then inside the setter read from the object

 public void setData(List < Report > data) { System.out.println("Setter Call Flow"); this.data = data; } 

Where Report is a java class containing id, code, name as its members with setters and getters.