Jackson converts a Java object to a JSON string

Jackson can convert a Java object to a JSON string, in the following steps:

1. Import Jackson's jar package

2. Create a Objectmapper object

3. Convert a Java object to a JSON object using the Writevalueasstring () method of the Objectmapper object

Here's an example:

 Public classFruit {PrivateString name; PrivateString ID;  PublicCustomet (string name, string id) {Super();  This. Name =name;  This. ID =ID; }     PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }    //@JsonIgnore     PublicString getId () {returnID; }     Public voidsetId (String id) { This. ID =ID; }     PublicString getDate () {return"2017-04-09"; }     Public Static voidMain (string[] args)throwsjsonprocessingexception {objectmapper mapper=NewObjectmapper (); Fruit Fruit=NewFruit ("Hamigua", "1001"); String Mapjakcson=mapper.writevalueasstring (fruit);    System.out.println (Mapjakcson); }}

The following JSON string is displayed by output to the console

{"Name": "Hamigua", "id": "1001", "Date": "2017-04-09"}

Note: Jackson determines JSON object properties by getter method, such as the GETDATE () method above, and if changed to Getfruitdate (), the date in the JSON string displayed by the console changes to Fruitdate At the same time, there is an annotation @jsonignore this property is ignored by the JSON string when it is preceded by a getter () method.

Jackson converts a Java object to a JSON string