[json]fasterxml.jackson常用资料

左手的ㄟ右手 2022-08-06 03:15 202阅读 0赞

环境

jackson-databind 2.4.4(用于spring mvc 3.2.11)

该工具类能解决的问题：

1.名称能通过JsonProperties修改

2.可以控制空值属性是否显示

3.可以忽略指定属性是否显示

package test;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Map;
    
    import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
    import com.fasterxml.jackson.annotation.JsonInclude;
    import com.fasterxml.jackson.annotation.JsonInclude.Include;
    import com.fasterxml.jackson.annotation.JsonProperty;
    import com.fasterxml.jackson.annotation.JsonRootName;
    
    //最外层加上“user”包裹
    //Deserial时需配合ObjectMapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true)使用
    //Serial时需配合ObjectMapper.configure(SerializationFeature.WRAP_ROOT_VALUE, true)使用
    @JsonRootName(value = "user")
    // 包含属性类型
    @JsonInclude(Include.NON_NULL)
    // 忽略的属性
    @JsonIgnoreProperties(ignoreUnknown = true)
    public class User {
    
    	public String toString() {
    		return "name:" + name + ",age:" + age;
    	}
    
    	@JsonProperty(value = "BaseName")
    	String name;
    	int age;
    
    	List<Map<String, Object>> mylist = new ArrayList<Map<String, Object>>();
    
    	Map<String, Object> mymap;
    
    	public String getName() {
    		return name;
    	}
    
    	public List<Map<String, Object>> getMylist() {
    		return mylist;
    	}
    
    	public void setMylist(List<Map<String, Object>> mylist) {
    		this.mylist = mylist;
    	}
    
    	public Map<String, Object> getMymap() {
    		return mymap;
    	}
    
    	public void setMymap(Map<String, Object> mymap) {
    		this.mymap = mymap;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public int getAge() {
    		return age;
    	}
    
    	public void setAge(int age) {
    		this.age = age;
    	}
    
    }

package test;
    
    import com.fasterxml.jackson.databind.DeserializationFeature;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import com.fasterxml.jackson.databind.SerializationFeature;
    
    public class JsonTest {
    
    	public static void main(String[] args) throws Exception {
    		ObjectMapper om = new ObjectMapper();
    
    		String s = "{\"user\":{\"age\":111,\"BaseName\":\"你好\"}}";
    		om.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true);
    		User user1 = om.readValue(s, User.class);
    		System.out.println(user1);
    
    		User user2 = new User();
    		user2.setAge(23);
    		user2.setName("你好");
    		om.configure(SerializationFeature.WRAP_ROOT_VALUE, true);
    		String str = om.writeValueAsString(user2);
    		System.out.println(str);
    	}
    
    }