java uses JSONObject instance

1. Introduction of jar package
Using JSONObject must reference JSON-lib.jar, and it also depends on other packages
common-lang.jar
common-beanuitls.jar
common-collections .jar
common-logging.jar
ezmorph.jar
2. Use of JSONObject objects
The JSON-lib package is a package for converting java objects, xml, and JSON to each other.
1. Convert Java objects into json strings

Person p1=new Person();
p1.setName("刘大江");
p1.setAge(26);
String jsonStr=JSONObject.fromObject(p1).toString();

2. Convert Java collections into json strings

        Person p1=new Person();p1.setName("A1");p1.setAge(26);
        Person p2=new Person();p2.setName("A2");p2.setAge(23);

        List personList=new ArrayList<Person>();
        personList.add(p1);
        personList.add(p2);

        Map personMap=new HashMap<String, Person>();
        personMap.put("p1", p1);
        personMap.put("p2", p2);

        //[{"age":26,"name":"A1"},{"age":23,"name":"A2"}]
        JSONArray.fromObject(personList).toString();
 JSONSerializer.toJSON(personList)

        //[{"p2":{"name":"A2","age":23},"p1":{"name":"A1","age":26}}]
        JSONArray.fromObject(personMap).toString();
 JSONSerializer.toJSON(personMap)

3. Convert json strings into dynamic Java objects

 String jsonStr="[{\"name\":\"A2\",\"age\":23},{\"name\":\"A1\",\"age\":26}]";
        JSONArray ja=JSONArray.fromObject(jsonStr);

        for(int i=0;i<ja.size();i++){
            JSONObject jo= ja.getJSONObject(i); //转换成JSONObject对象
            System.out.println(jo.get("name"));

            Person p=(Person)JSONObject.toBean(jo,Person.class);    //转换成JavaBean
            System.out.println(p.getName()); 

        }

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