使用Struts将Java bean转换为json字符串

Question

I want to use struts to render content in a JSP page.

I have the Java Bean class implementing Serializable :

public class MyPOJO implements Serializable {
    String name;
    int value;
    // A lot of other members, but all String or int
    // Getters and setters
}

And my form class with a list of MyPOJO:

public class MyForm extends ActionForm {
    private List<MyPOJO> results = new ArrayList<MyPOJO>();
    // Getter and setter
}

And a class inheriting DispatchAction to pass a MyForm object onto the page.

On the jsp page I use:

<logic:notEmpty name="myForm" property="results">
var jsonData = ${myForm.results};
</logic:notEmpty>

The final result in the generated jsp file is a list of MyPOJO objects:

var jsonData = [com.package.MyPOJO@174aee5, ...]

I'd like to know, without overriding toString() method inside MyPOJO class is there any other way to directly convert it to json String? I've also created a rest service returning a list of MyPOJO, without the toString() method, it can already show the JSON string, I'd like to know why it doesn't work for the JSP form bean?

Answer 1

Because you didn't override ArrayList toString() method. Your property is a collection that has to be serialied to JSON. You could either extend ArrayList and override that method or use natively JSONArray or JSONObject toString() that is already overridden and returns a JSON string.