Json To Java Object Using Gson

I am using GSON library for turing JSON that comes form a web service but I can't make it work, I always get a null. I've looked through similar issues like Converting Json to Java

Solution 1:

Since its a static inner class .As docs pointed out and comments :

As well, if a field is marked as "static" then by default it will be excluded. If you want to include some transient fields...

You may want to try

Gsongson=newGsonBuilder()
    .excludeFieldsWithModifier()
    .create();

Also, since its a inner class you may need to change your JSON If you can:

 {
   "site":{
      "A":"val1",
      "B":"val2",
      "C":"val3",
      "D":"val4",
      "E":"val5",
      "F":"val6",
      "G":"val7"
   }
}

As noted here in this post

Solution 2:

The issue is that in your code you're passing SiteWrapper.class when you should be passing Site.class to gson.fromJSON

This line

SiteWrapper m = gson.fromJson(json, SiteWrapper.class);

should be

Site s = gson.fromJSON(json, Site.class);

Site is the class you defined for the JSON provided. SiteWrapper contains a site variable, you need to set this Site variable to the result of the fromJSON

Solution 3:

Per this documentation, all static fields are excluded by default. Follow the example in the link to alter the default exclusion strategy so that statics are accepted.

When you create your Gson object, try the following:

Gsongson=newGsonBuilder()
    .excludeFieldsWithModifier(Modifier.TRANSIENT,Modifier.VOLATILE)
    .create();

This should create a Gson object that will not exclude static fields by default.