Jackson ObjectMapper

Jackson ObjectMapper

• Java에서 Json를 다룰때 주로 사용하는 Jackson ObjectMapper에 대해 정리를 해보자.

Gradle

compile "com.fasterxml.jackson.core:jackson-databind:2.9.4"

ObjectMapper를 이용한 Json Write, Read

public class Car {

    private String color;

    private String type;

}

Json Write

ObjectMapper objectMapper = new ObjectMapper();

Car car = new Car("yellow", "bmw");

String carAsString = objectMapper.writeValueAsString(car);

Json Read

String json = "{ \"color\" : \"Black\", \"type\" : \"BMW\" }";

Car car = objectMapper.readValue(json, Car.class); 

Annotation

@JsonProperty

public class MyBean {

    public int id;

    private String name;

 

    @JsonProperty("name")

    public void setTheName(String name) {

        this.name = name;

    }

 

    @JsonProperty("name")

    public String getTheName() {

        return name;

    }

}

@JsonSerialize

public class Event {

    public String name;

 

    @JsonSerialize(using = CustomDateSerializer.class)

    public Date eventDate;

}

@JsonDeserialize

public class Event {

    public String name;

 

    @JsonDeserialize(using = CustomDateDeserializer.class)

    public Date eventDate;

}

@JsonIgnore

public class BeanWithIgnore {

    @JsonIgnore

    public int id;

 

    public String name;

}

@JsonIgnoreProperties({ "id" })

@JsonIgnoreProperties({ "id" })

public class BeanWithIgnore {

    public int id;

    public String name;

}

@JsonAnyGetter

public class ExtendableBean {

    public String name;

    private Map<String, String> properties;

 

    @JsonAnyGetter

    public Map<String, String> getProperties() {

        return properties;

    }

}

{

    "name":"My bean",

    "attr2":"val2",

    "attr1":"val1"

}

@JsonAnySetter

public class ExtendableBean {

    public String name;

    private Map<String, String> properties;

 

    @JsonAnySetter

    public void add(String key, String value) {

        properties.put(key, value);

    }

}

public class ExtendableBean {

    public String name;

    private Map<String, String> properties;

 

    @JsonAnySetter

    public void add(String key, String value) {

        properties.put(key, value);

    }

}