Gson parsing JSON data (RPM)

One

Www.json.org This is the official website of JSON.

First of all, I, we need to download the JSON jar package in Code.google.com/p/google-gson/downloads/list, parse and import the Gson-1.6.jar file into the project you need to parse.

Parse the JSON example as follows:

1, this is the JSON data, "[{\" name\ ": \" michael\ ", \" age\ ": 20},{\" name\ ": \" mike\ ", \" age\ ": 21}]"

2.

Create a Jsonreader object

Jsonreader reader = new Jsonreader (new StringReader (Jsondata));

Start parsing an array

Reader.beginarray ();

Loop to determine if there is no next JSON object

while (Reader.hasnext ()) {

Start parsing JSON objects

Reader.beginobject ();

}

Loop to determine if there is no next key value pair in the JSON object

while (Reader.hasnext ()) {

String tagName = Reader.nextname ();

if (tagname.equal ("name")) {

Name key multiple corresponding value

Reader.nextstring ();

}else if (tagname.equal ("Age")) {

Age key multiple corresponding value

Reader.nextstring ();

}

}

End of JSON object

Reader.endobject ();

}

End of Array parsing

Reader.endarray ();

Two

This example can only be done for JSON objects, not JSON arrays, and JSON arrays need to be converted to JSON objects, which is the next section.

1. There is a JSON object string str = "{\" name\ ": \" michael\ ", \" age\ ": $}", JSON class can directly convert JSON data into Java object

2. Create the User class

public class user{

private String name;

private int age;

public void SetName (String name) {

THIS.name = name;

}

Public String GetName () {

return name;

}

public void Setage (int.) {

This.age = age;

}

public int getage () {

return age;

}

}

3. Create a Gson object

Gson Gson = new Gson ();

The second is an object that indicates which class to convert to

User user = Gson.fromjson (str, user.class);

Sysout.out.println (User.getname);

Sysout.out.println (User.getage);

Three

　　　　

1. This is the JSON data, String str = "[{\" name\ ": \" michael\ ", \" age\ ": 20},{\" name\ ": \" mike\ ", \" age\ ": 21}]". This JSON data has an array with two JSON objects inside the array.

2. You must first generate a type object, using the following method (user is the user class in the previous section):

Type ListType = new typetoken<linkedlist<user>> () {}.gettype ();

3. Generating Gson objects

Gson Gson = new Gson ();

4. Linkedlist<user> users = Gson.fromjson (str, listtype);

5. Cyclic Iteration LinkedList

for (Iterator Iterator = Users.iterator; Iterator.hasnext ();) {

User user = (user) iterator.next ();

System.out.println (User.getname ());

System.out.println (User.getage ());

}