The Java object and the JSON string are transferred to each other

1:java object and JSON string conversion:

Java Object-json string:

Jsonobject jsonstr = Jsonobject.fromobject (object);

String str = jsonstr.tostring ();

JSON string-java object:

Jsonobject jsonobject = Jsonobject.fromobject (jsonstring);

Object Pojo = Jsonobject.tobean (JSONOBJECT,POJOCALSS);

2:java array objects with JSON string conversions:

Java Array-json string:

Jsonarray arraystr = jsonarray.fromobject (list<?>);

String str = arraystr.tostring ();

JSON string-java array:

Jsonarray array = jsonarray.fromobject (str);

list<?> list = jsonarray.tolist (array,?. Class);

1. from object to string
To construct a jsonobject or Jsonarray object with object, then call its ToString () method to

(1) Example one

1 book book=new Book ();  2 Book.setname ("Java"); 3 Book.setprice (52.3f); 4 jsonobject object=jsonobject.fromobject (book); 5 System.out.println (object.tostring ());    

(2) Example two

1 book book=new book ();2 Book.setname ("Java");3 Book.setprice (52.3f);45 Book Book2=new book ();6 Book2.setname ("C"); 7 Book2.setprice (42.3f);  8 List list=new ArrayList ();  9 List.add (book); 10 List.add (BOOK2); 11 jsonarray arry=jsonarray.fromobject (list); 12 System.out.println (Arry.tostring ()); 13 //14 [{"Name": "Java", "Price": 52.3},{"name": "C", "Price": 42.3}]    

2. From string to Object
To construct a jsonobject or Jsonarray object with a string object first
(1) Example one

1 String json= "{name: ' Java ', price:52.3}";     2 jsonobject object=jsonobject.fromobject (JSON);  3 System.out.println (Object.get ("name") + "" "+object.get (" price "); 

(2) Example two

1 String json= "[{name: ' Java ', price:52.3},{name: ' C ', price:42.3}]";  2 Jsonarray array=jsonarray.fromobject (JSON);  for (int i=0;i<array.size (); i++) {4 map o= (map) array.get (i);  5 System.out.println (O.get ("name") + "" "+o.get (" price "); 6}     

3. From string to Bean

(1) Single Bean object

1         String json= "{name: ' Java ', price:52.3}";  2         Jsonobject Object=jsonobject.fromobject (JSON); 3 Product product= (product) Jsonobject.tobean (object,product.  Class); 4 System.out.println (product.getname () + "" +product.getprice ());   

(2). An array of beans

1         String json= "[{name: ' Java ', price:52.3},{name: ' C ', price:42.3}]";  2         Jsonarray Array=jsonarray.fromobject (JSON); 3 product[] products= (product[]) Jsonarray.toarray (array,product.  Class); For (Product p:products) {5 System.out.println (p.getname () + "" +p.getprice ());  6}     

Customizing classes that encapsulate JSON operations

1Package com.util;23Import java.util.List;4Import Java.util.Map;56Import Net.sf.json.JSONArray;7Import Net.sf.json.JSONObject;89PublicClass Jsonhelper {10//Converting from a normal bean to a string11PublicStatic String Getjson (Object o) {Jsonobject Jo=jsonobject.fromobject (o);13return jo.tostring ();14}15//Converting from a list of Java to a string16PublicStatic String Getjson (List list) {Jsonarray ja=jsonarray.fromobject (list);18return ja.tostring ();19}20//Converting from a Java object array to a string21stPublicStatic String Getjson (object[] arry) {Jsonarray Ja=jsonarray.fromobject (Arry);23return ja.tostring ();24}25//Convert a string from JSON format to a map object26PublicStatic Map GetObject (String s) {27return Jsonobject.fromobject (s);28}29//Convert from JSON-formatted string to list array30PublicStatic List GetArray (String s) {31return Jsonarray.fromobject (s);32}33//Converting from a JSON-formatted string to a bean34PublicStatic Object GetObject (String s,class cls) {Jsonobject Jo=jsonobject.fromobject (s);36 return Jsonobject.tobean (Jo, CLS); 37}38 // convert from a JSON-formatted string to an array of objects of a class public static Object GetArray (String s,class cls) { Span style= "FONT-SIZE:16PX;" >40 Jsonarray Ja=jsonarray.fromobject (s); 41 return Jsonarray.toarray (JA, CLS); 42}43}                 

The Java object and the JSON string are transferred to each other