SpringBoot2序列化相关

最常用的序列化

将null值不序列化

@Bean
@Primary
@ConditionalOnMissingBean(ObjectMapper.class)
public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
    ObjectMapper objectMapper = builder.createXmlMapper(false).build();
    //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，属性为NULL 不序列化
    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    return objectMapper;
}

将null值序列化为””

@Bean
@Primary
@ConditionalOnMissingBean(ObjectMapper.class)
public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
    ObjectMapper objectMapper = builder.createXmlMapper(false).build();
    // 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,字段保留，将null值转为""
    objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
        @Override
        public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
            jsonGenerator.writeString("");
        }
    });
    return objectMapper;
}

将Long和long转字符串

// 使用的序列化工具是jackson
@Bean
public MappingJackson2HttpMessageConverter longToStringConverter() {
    MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
    ObjectMapper mapper = new ObjectMapper();
    SimpleModule simpleModule = new SimpleModule();
    simpleModule.addSerializer(Long.class, ToStringSerializer.instance);//Long
    simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);//long
    mapper.registerModule(simpleModule);
    converter.setObjectMapper(mapper);
    return converter;
}