Serializing and Deserializing Generic Types When you call toJson(obj), Gson calls obj.getClass() to get information on the fields to serialize. Similarly, you can typically pass MyClass.class object in the fromJson(json, MyClass.class) method. This works fine if the object is a non-generic type. However, if the object is of a generic type, then the Generic type … Read more
I think most of those settings you have there are already included in the Android SDK by default. So you can remove most of them, just leaving in the section devoted to GSON. I am developing in Eclipse using Android SDK Tools 22.6.3 & whatever version of ProGuard ships with that. Here’s what I’m using … Read more
I faced the same issue. I just added a single line as shown below in my build.gradle dependencies (without adding any jar in project structure) and it worked for me. dependencies { compile ‘com.google.code.gson:gson:2.2.+’ compile ‘com.android.support:support-v4:13.0.+’ compile ‘com.android.support:appcompat-v7:18.0.+’ } Along with above, I found few more things which are required for this to work. Make … Read more
Use TypeToken, as per the GSON FAQ: Gson gson = new Gson(); Type stringStringMap = new TypeToken<Map<String, String>>(){}.getType(); Map<String,String> map = gson.fromJson(json, stringStringMap); No casting. No unnecessary object creation.
The error occurs when you are deserializing the LocalDateTime attribute because GSON fails to parse the value of the attribute as it’s not aware of the LocalDateTime objects. Use GsonBuilder’s registerTypeAdapter method to define the custom LocalDateTime adapter. Following code snippet will help you to deserialize the LocalDateTime attribute. Gson gson = new GsonBuilder().registerTypeAdapter(LocalDateTime.class, new … Read more
Use a JSON library to parse the string and retrieve the value. The following very basic example uses the built-in JSON parser from Android. String jsonString = “{ \”name\” : \”John\”, \”age\” : \”20\”, \”address\” : \”some address\” }”; JSONObject jsonObject = new JSONObject(jsonString); int age = jsonObject.getInt(“age”); More advanced JSON libraries, such as jackson, … Read more
@Baldy answer is the same as: implementation ‘com.fasterxml.jackson.core:jackson-core:2.10.1’ implementation ‘com.fasterxml.jackson.core:jackson-annotations:2.10.1’ implementation ‘com.fasterxml.jackson.core:jackson-databind:2.10.1’ Following android studio conventions. You can find the up to date version at: Maven Central Repository.
The -07:00 is the ISO 8601 time zone notation. This is not supported by SimpleDateFormat until Java 7. So, if you can upgrade to Java 7, then you can use the X to represent that time zone notation: Gson gson = new GsonBuilder().setDateFormat(“yyyy-MM-dd’T’HH:mm:ssX”).create(); On Java 6 you would need to do some pattern matching and … Read more
I’d take a slightly different approach as follows, so as to minimize “manual” parsing in my code, as unnecessarily doing otherwise somewhat defeats the purpose of why I’d use an API like Gson in the first place. // output: // [User: id=1, name=Jonas, updateDate=2011-03-24 03:35:00.226] // [User: id=5, name=Test, updateDate=2011-05-07 08:31:38.024] // using java.sql.Timestamp public … Read more
As of Gson 2.3.1. Regardless of what the Gson documentation says, if your class doesn’t have an no-args constructor and you have not registered any InstanceCreater objects, then it will create an ObjectConstructor (which constructs your Object) with an UnsafeAllocator which uses Reflection to get the allocateInstance method of the class sun.misc.Unsafe to create your … Read more