解决SerializationFeature.FAIL_ON_EMPTY_BEANS异常

在使用spring boot + jpa/hibernate，如果实体字段上加有FetchType.LAZY，并使用jackson序列化为json串时，会遇到SerializationFeature.FAIL_ON_EMPTY_BEANS异常，网上查了一下，测试了一下发现 中处理方案的“ WebMvcConfigurerAdapter”已过期，现在改用“WebMvcConfigurationSupport”。 解决办法：

// An highlighted block
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.hibernate4.Hibernate4Module;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

import java.util.List;

@Configuration
public class JacksonConfiguration extends WebMvcConfigurationSupport {
          
   
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
          
   
        converters.add(jacksonMessageConverter());
        super.configureMessageConverters(converters);
    }

    private MappingJackson2HttpMessageConverter jacksonMessageConverter() {
          
   
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        ObjectMapper mapper = new ObjectMapper();
        mapper.registerModule(new Hibernate4Module());
        messageConverter.setObjectMapper(mapper);
        return messageConverter;
    }
}

即给Jackson注册Hibernate4Module模块。

Hibernate4Module模块对应的maven为：

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-hibernate4</artifactId>
    <version>2.4.6</version>
</dependency>