@JsonInclude.Include.CUSTOM 自定义属性值过滤规则

灰太狼 2024-03-30 16:36 40阅读 0赞

使用 `@JsonInclude＃value = JsonInclude.Include.CUSTOM` 并通过 `@ JsonInclude＃valueFilter` 指定一个过滤器类(equals入参为本字段)，则该属性值只有在没有被过滤器类过滤的情况下才会被序列化。过滤器类的 `equals()` 方法用于过滤值；如果返回true，则值不会序列化。

同样，使用 `@JsonInclude＃content= JsonInclude.Include.CUSTOM` 并通过 `@JsonInclude#contentFilter` 指定过滤器(equals入参为本字段的values)，则如果过滤器类的 `equals()`方法返回true，则不会序列化目标属性的内容值

## Example ##

package com.jothan.jackson;
    
    import com.fasterxml.jackson.annotation.JsonInclude;
    import com.fasterxml.jackson.core.JsonProcessingException;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import java.time.ZonedDateTime;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.regex.Pattern;
    @Data
    public class Employee {
        
        private String name;
    
        @JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = DateOfBirthFilter.class)
        private Date dateOfBirth;
        
        @JsonInclude(content = JsonInclude.Include.CUSTOM, contentFilter = PhoneFilter.class)
        private Map<String, String> phones;
    
    
        // 必须静态内部类，否则报找不到无参构造
        @NoArgsConstructor
        public static class DateOfBirthFilter {
        
            @Override
            public boolean equals(Object obj) {
        
                if (obj == null || !(obj instanceof Date))
                    return false;
    
                Date date = (Date) obj;
                return !date.before(new Date());
            }
        }
    
        @NoArgsConstructor
        public static class PhoneFilter {
        
            private static Pattern phonePattern = Pattern.compile("\\d{3}-\\d{3}-\\d{4}");
    
            // 会把 private Map<String, String> phones; 的values当作入参
            @Override
            public boolean equals(Object obj) {
        
                if (obj == null || !(obj instanceof String))
                    return false;
    
                return phonePattern.matcher(obj.toString()).matches();
            }
        }
    
        public static void main(String[] args) throws JsonProcessingException {
        
            Employee employee = new Employee();
            employee.setName("Trish");
            employee.setDateOfBirth(Date.from(ZonedDateTime.now().plusDays(1).toInstant()));
            employee.setPhones(new HashMap<String,String>() {
        {
        
                put("Cell", "111-111-1111");
                put("Work", "(222) 222 2222");
            }});
    
    
            ObjectMapper om = new ObjectMapper();
            String jsonString = om.writeValueAsString(employee);
            System.out.println(jsonString);
    
        }
    
    
    }

{"name":"Trish","phones":{"Work":"(222) 222 2222"}}

### 不使用自定义过滤器 ###

{"name":"Trish","dateOfBirth":1619091861386,"phones":{"Work":"(222) 222 2222","Cell":"111-111-1111"}}

## 原文链接 ##

[Jackson JSON - Applying Custom property inclusion rules using @JsonInclude.Include.CUSTOM][Jackson JSON - Applying Custom property inclusion rules using _JsonInclude.Include.CUSTOM]

[Jackson JSON - Applying Custom property inclusion rules using _JsonInclude.Include.CUSTOM]: https://www.logicbig.com/tutorials/misc/jackson/json-include-customized.html