Jackson2.1.4 序列化对象时,过滤null的属性 empty的属性 default的属性

在进行序列化如何过滤为null的属性,empty的属性,或者default的属性。

 

一、全局注册 objectMapper.setSerializationInclusion(Include.ALWAYS);

二、具体类上打注解

@JsonSerialize(include = Inclusion.NON_NULL) public class MyTypeWithoutNulls {   public String mayHaveValue; // will not be included if value is null

}

三、具体属性上打注解

@JsonInclude(Include.NON_NULL) public Date getBirthday() {   return birthday; }

 

测试用例

public class User { private int id; private String name; private Date birthday; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; }
//将该标记放在属性上,如果该属性为NULL则不参与序列化 //如果放在类上边,那对这个类的全部属性起作用 //Include.Include.ALWAYS 默认 //Include.NON_DEFAULT 属性为默认值不序列化 //Include.NON_EMPTY 属性为 空(“”) 或者为 NULL 都不序列化 //Include.NON_NULL 属性为NULL 不序列化 @JsonInclude(Include.NON_NULL) public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } }
//测试方法

ObjectMapper mapper = new ObjectMapper(); User user = new User(1,"jack",null); String outJson = mapper.writeValueAsString(user); System.out.println(outJson); //测试结果 //{"id":1,"name":"jack"}
ObjectMapper mapper = new ObjectMapper(); //通过该方法对mapper对象进行设置,所有序列化的对象都将按改规则进行系列化 //Include.Include.ALWAYS 默认 //Include.NON_DEFAULT 属性为默认值不序列化 //Include.NON_EMPTY 属性为 空(“”) 或者为 NULL 都不序列化 //Include.NON_NULL 属性为NULL 不序列化

mapper.setSerializationInclusion(Include.NON_NULL); User user = new User(1,"",null); String outJson = mapper.writeValueAsString(user); System.out.println(outJson);

 

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