Explain the simple use of Android native JSON and fastjson

Android native operation JSON data

There are mainly two classes: jsonobject operation object and jonsarray operation JSON array

Object to JSON

Log log display

JSON to object

Create a new jsonobject, assign the JSON string through the construction method, the jsonobject object will have the JSON value, and then create an object to assign the value one by one. Jsonobject has different get methods for different types of values

List to JSON

Using jonsarray

JSON to list

Note: exceptions need to be caught in the process of using jsonobject and jsonarray

Do you feel very troublesome? If there are too many data, it's exhausting

The way to make it easier is to download fastjson.jar, which is known as the fastest JSON operation in history, and then use it

Fastjason operation data

Object to JSON

It's done in one sentence. It's so simple. Thank you Ma yunbaba!!!

JSON to object

Similarly, there is only one sentence, which is really touching compared with Android native

List to JSON

When three objects are added to the collection, the output of the JSON string becomes ref, {0} obviously, this is the first object to reference. Because you add the same object, fastjson does not create a direct reference, which is also the reason why it claims to be the fastest

However, there is a problem that fastjson can identify and reference other jars. What if the server uses fastjson and the client uses gson

1. All use fastjson

2. When converting to JSON, set a property to disable the circular reference object

json=JSON.toJSONString(stuList,SerializerFeature.DisableCircularReferenceDetect);

JSON to list

Sometimes, you don't need all the fields in the object. At this time, you can set a property filter to filter out the fields you don't need

Set name filtering. Please see the log

Introducing a situation

Defines a generic class

There is a student object and a string

Convert object to JSON

When we want to turn this JSON into an object, the problem comes

At this time, you need to implement the typereference class to encapsulate the object

Perfect solution. Typereference can be used for all types with generics

Finally, I will introduce a website to you http://json.cn/ Especially powerful, it will automatically format JSON and report errors if there are syntax errors

The above is the whole content of this article. I hope the content of this article can bring some help to your study or work. At the same time, I also hope to support a lot of programming tips!