gson spring boot
pom.xml
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.5</version>
</dependency>
In your class
toJson() – Convert Java objects to JSON
Gson gson = new Gson();
// 1. Java object to JSON file
Staff obj = new Staff();
gson.toJson(obj, new FileWriter("C:\\projects\\staff.json"));
// 2. Java object to JSON string
String jsonInString = gson.toJson(obj);
fromJson() – Convert JSON to Java objects
Gson gson = new Gson();
// 1. JSON file to Java object
Staff staff = gson.fromJson(new FileReader("C:\\projects\\staff.json"), Staff.class);
// 2. JSON string to Java object
String json = "{'name' : 'mkyong'}";
Staff staff = gson.fromJson(json, Staff.class);
// 3. JSON file to JsonElement, later String
JsonElement json = gson.fromJson(new FileReader("C:\\projects\\staff.json"), JsonElement.class);
String result = gson.toJson(json);