1、新增jackson庫

如果是maven工程，需要在pom.xml中新增jackson的依賴：

			<dependency>
				<groupId>com.fasterxml.jackson.core</groupId>
				<artifactId>jackson-databind</artifactId>
				<version>2.8.3</version>
			</dependency>

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.DeserializationFeature;
 

2、json轉object

比如本例中是YourJson（json型別字串）需要轉化為YourClass類(自定義的類)的例項：

ObjectMapper objectMapper = new ObjectMapper();
YourClass class = objectMapper.readValue(YourJson, YourClass.class);

1）需要加上如下語句：

這種方法的好處是不用改變要轉化的類，即本例的YourClass。（如果YourClass不是你維護的，或者不可修改的，可以用這個方法）

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
YourClass class = objectMapper.readValue(YourJson, YourClass.class);

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class YourClass {
    ...
}
 

本例中是YourClass物件需要轉化為json：

import com.fasterxml.jackson.databind.ObjectMapper;

ObjectMapper objectMapper = new ObjectMapper();
YourClass yourClass = new YourClass();
String json = objectMapper.writeValueAsString(yourClass);