使用GSON从Ajax请求解析JSON数组

Question

my json string is:

[{"name":"51","value":"0"},{"name":"52","value":"0"},{"name":"53","value":"5"},{"name":"54","value":"1"},{"name":"106","value":"0"},{"name":"107","value":"0"},{"name":"108","value":"3"}]

I am trying to do:

Gson gson = new Gson();
    class Wrapper{
        String name;
        String value;       
    }
Wrapper[] arr = gson.fromJson(request.getParameter("data"), Wrapper[].class);

And then:

for (Wrapper arr1 : arr) {
        if(Long.parseLong(arr1.value)!=0){
            listeProduits.add(ServiceMetier.getProduitById(Long.parseLong(arr1.name)));
            listeQuantites.add(Long.parseLong(arr1.value));
        }
    }

But I am always getting:

May 08, 2017 11:32:06 AM org.apache.catalina.core.StandardWrapperValve 
invoke
SEVERE: Servlet.service() for servlet [ActionServlet] in context with path 
[/Gustatif_Web] threw exception
java.lang.NullPointerException

The null pointer is on arr1. What am I doing wrong with my json parsing?

Edit: one problem was having the Wrapper class inside the method, another problem was deeper within the dependencies to another project.

Answer 1

i have try it ; your code has a little error; you must create a new java class－－ Wrapper，do not be the inner class of this Method.