15.springmvc源码学习（十五）ObjectMapper的注册

目录

• 一、JacksonObjectMapperConfiguration
• 二、JacksonObjectMapperBuilderConfiguration
• 三、Jackson2ObjectMapperBuilderCustomizerConfiguration
• 四、StandardJackson2ObjectMapperBuilderCustomizer
• 总结

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一、JacksonObjectMapperConfiguration

创建@Bean ObjectMapper ，通过Jackson2ObjectMapperBuilder

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	static class JacksonObjectMapperConfiguration {

		@Bean
		@Primary
		@ConditionalOnMissingBean
		ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
			return builder.createXmlMapper(false).build();
		}

	}

二、JacksonObjectMapperBuilderConfiguration

创建@Bean Jackson2ObjectMapperBuilder，通过Jackson2ObjectMapperBuilderCustomizer实现定制化

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	static class JacksonObjectMapperBuilderConfiguration {

		@Bean
		@Scope("prototype")
		@ConditionalOnMissingBean
		Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder(ApplicationContext applicationContext,
				List<Jackson2ObjectMapperBuilderCustomizer> customizers) {
			Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
			builder.applicationContext(applicationContext);
			//实现定制化
			customize(builder, customizers);
			return builder;
		}

		private void customize(Jackson2ObjectMapperBuilder builder,
				List<Jackson2ObjectMapperBuilderCustomizer> customizers) {
			for (Jackson2ObjectMapperBuilderCustomizer customizer : customizers) {
				//调用Jackson2ObjectMapperBuilderCustomizer 的customize()
				customizer.customize(builder);
			}
		}

	}

三、Jackson2ObjectMapperBuilderCustomizerConfiguration

创建@Bean StandardJackson2ObjectMapperBuilderCustomizer

注入参数 JacksonProperties

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	@EnableConfigurationProperties(JacksonProperties.class)
	static class Jackson2ObjectMapperBuilderCustomizerConfiguration {

		@Bean
		StandardJackson2ObjectMapperBuilderCustomizer standardJacksonObjectMapperBuilderCustomizer(
				ApplicationContext applicationContext, JacksonProperties jacksonProperties) {
			return new StandardJackson2ObjectMapperBuilderCustomizer(applicationContext, jacksonProperties);
		}

}

四、StandardJackson2ObjectMapperBuilderCustomizer

实现了Jackson2ObjectMapperBuilderCustomizer，并通过配置文件配置JacksonProperties 的属性来实现定制化

static final class StandardJackson2ObjectMapperBuilderCustomizer
				implements Jackson2ObjectMapperBuilderCustomizer, Ordered {

			private final ApplicationContext applicationContext;

			private final JacksonProperties jacksonProperties;

			StandardJackson2ObjectMapperBuilderCustomizer(ApplicationContext applicationContext,
					JacksonProperties jacksonProperties) {
				this.applicationContext = applicationContext;
				this.jacksonProperties = jacksonProperties;
			}

			@Override
			public int getOrder() {
				return 0;
			}

			@Override
			//定制化的方法
			public void customize(Jackson2ObjectMapperBuilder builder) {
				if (this.jacksonProperties.getDefaultPropertyInclusion() != null) {
					builder.serializationInclusion(this.jacksonProperties.getDefaultPropertyInclusion());
				}
				if (this.jacksonProperties.getTimeZone() != null) {
					builder.timeZone(this.jacksonProperties.getTimeZone());
				}
				configureFeatures(builder, FEATURE_DEFAULTS);
				configureVisibility(builder, this.jacksonProperties.getVisibility());
				configureFeatures(builder, this.jacksonProperties.getDeserialization());
				configureFeatures(builder, this.jacksonProperties.getSerialization());
				configureFeatures(builder, this.jacksonProperties.getMapper());
				configureFeatures(builder, this.jacksonProperties.getParser());
				configureFeatures(builder, this.jacksonProperties.getGenerator());
				configureDateFormat(builder);
				configurePropertyNamingStrategy(builder);
				configureModules(builder);
				configureLocale(builder);
			}
			......
}

---

总结

可以通过实现Jackson2ObjectMapperBuilderCustomizer来定制化ObjectMapper 。

来源：https://blog.csdn.net/RenshenLi/article/details/119303542