该 @JsonProperty 注解可以用于指示属性名的JSON。此批注可用于构造函数 或工厂方法。该@JsonCreator在注释中是十分有用@JsonSetter注释不能使用。例如,不可变对象没有任何设置方法,因此它们需要将其初始值注入到构造函数中。
import com.fasterxml.jackson.annotation.*; import java.io.IOException; import com.fasterxml.jackson.databind.*; public class JsonCreatorTest1 { public static void main(String[] args) throws IOException { ObjectMapper om = new ObjectMapper(); String jsonString = "{\"id\":\"101\", \"fullname\":\"Ravi Chandra\", \"location\":\"Pune\"}"; System.out.println("JSON: " + jsonString); Customer customer = om.readValue(jsonString, Customer.class); System.out.println(customer); } }// Customer classclass Customer { private String id; private String name; private String address; public Customer() { } @JsonCreator public Customer( @JsonProperty("id") String id, @JsonProperty("fullname") String name, @JsonProperty("location") String address) { this.id = id; this.name = name; this.address = address; } @Override public String toString() { return "Customer [id=" + id + ", name=" + name + ", address=" + address + "]"; } }
输出结果
JSON: {"id":"101", "fullname":"Ravi Chandra", "location":"Pune"}Customer [id=101, name=Ravi Chandra, address=Pune]
import com.fasterxml.jackson.annotation.*; import java.io.IOException; import com.fasterxml.jackson.databind.*; public class JsonCreatorTest2 { public static void main(String[] args) throws IOException { ObjectMapper mapper = new ObjectMapper(); String jsonString = "{\"id\":\"102\", \"fullname\":\"Raja Ramesh\", \"location\":\"Hyderabad\"}"; System.out.println("JSON: " + jsonString); Customer customer = mapper.readValue(jsonString, Customer.class); System.out.println(customer); } }// Customer classclass Customer { private String id; private String name; private String address; public Customer() { } @JsonCreator public static Customer createCustomer( @JsonProperty("id") String id, @JsonProperty("fullname") String name, @JsonProperty("location") String address) { Customer customer = new Customer(); customer.id = id; customer.name = name; customer.address = address; return customer; } @Override public String toString() { return "Customer [id=" + id + ", name=" + name + ", address=" + address + "]"; } }
输出结果
JSON: {"id":"101", "fullname":"Raja Ramesh", "location":"Hyderabad"}Customer [id=102, name=Raja Ramesh, address=Hyderabad]