Jackson Dynamic Property Filter

Basically, when you are using Gson and you need to exclude specific fields from Serialization WITHOUT annotations on the target object, you will use ExclusionStrategy. But I didn't find an similar way to do that in Jackson. So this repo provides an easy way to determine filters dynamically, and it also well integration with Spring MVC/Spring Boot.

For Spring Boot: jackson-dynamic-filter-spring-boot-starter

Requirements

• Java 8
• Supported Spring IO Platform:
  • Athens-SR1
  • Brussels-SR11
  • Cairo-SR2

Download

To add a dependency using Maven, use the following:

<dependency>
	<groupId>com.github.shihyuho</groupId>
	<artifactId>jackson-dynamic-filter</artifactId>
	<version>1.0.1</version>
</dependency>

To add a dependency using Gradle:

compile 'com.github.shihyuho:jackson-dynamic-filter:1.0.1'

To download directly: Releases

Usage

ObjectMapper mapper = new ObjectMapper();
mapper.addMixIn(Object.class, DynamicFilterMixIn.class);
mapper.setFilterProvider(new DynamicFilterProvider());

String jsonWithAllFields = mapper.writeValueAsString(someObject);

PropertyFilter someFilter = SimpleBeanPropertyFilter.serializeAllExcept("someField");
String jsonWithoutSomeField = mapper
	.writer(new DynamicFilterProvider(someFilter)) // determine custom filter 
    .writeValueAsString(someObject);

Spring intergration

Enabling in your Spring MVC

All you need to do is to wire DynamicFilterResponseBodyAdvice into your application. DynamicFilterResponseBodyAdvice implements Spring'sAbstractMappingJacksonResponseBodyAdvice and can be plugged in as follows:

@EnableWebMvc
@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

	@Override
	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
		ObjectMapper mapper = new ObjectMapper();
		mapper.addMixIn(Object.class, DynamicFilterMixIn.class);
		mapper.setFilterProvider(new DynamicFilterProvider());
		converters.add(new MappingJackson2HttpMessageConverter(mapper));
	}

	@Bean
	public DynamicFilterResponseBodyAdvice dynamicFilterResponseBodyAdvice() {
		return new DynamicFilterResponseBodyAdvice();
	}
}

If you're using Spring Boot, take a look on jackson-dynamic-filter-spring-boot-starter

Using annotation

• @SerializeAllExcept - Same as SimpleBeanPropertyFilter.serializeAllExcept(...)
• @FilterOutAllExcept - Same as SimpleBeanPropertyFilter.filterOutAllExcept(...)

@RestController
public class SomeController {
  
	@SerializeAllExcept({"someField", "anotherField"})
	@RequestMapping(value = "/without/some-fields", method = RequestMethod.GET)
	public SomeObject withoutSomeFields() {
		return someObject;
	}
	
	@FilterOutAllExcept({"someField", "anotherField"})
	@RequestMapping(value = "/only/some-fields", method = RequestMethod.GET)
	public SomeObject onlySomeFields() {
		return someObject;
	}
}

SimpleBeanPropertyFilter javadoc

Custom annotation

You can annotate a custom annotation:

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface WithoutAuditingFields {
}

public class WithoutAuditingFieldsResolver extends DynamicFilterProvider<WithoutAuditingFields> {
	@Override
	public PropertyFilter apply(WithoutAuditingFields annotation) {
		return SimpleBeanPropertyFilter.serializeAllExcept("id", "createdBy", "createdTime",
			"modifiedBy", "modifiedTime");
	}
}

register into DynamicFilterResponseBodyAdvice

@Bean
public DynamicFilterResponseBodyAdvice dynamicFilterResponseBodyAdvice() {
	DynamicFilterResponseBodyAdvice advice = new DynamicFilterResponseBodyAdvice();
	advice.addResolvers(new WithoutAuditingFieldsResolver());
	return advice;
}

and then use it for you controller as follows:

@RestController
public class SomeController {
  
	@WithoutAuditingFields
	@RequestMapping(value = "/some-path", method = RequestMethod.GET)
	public SomeObject getSomeObject() {
		return someObject;
	}
}