is it possible to convert long to string in spring boot rest api without using enablewebmvc annotation

Question

because the javascript could not handle the long data type , so I need to convert the backend java Long data type to string, is it possible to do like this? I am doing it like this:

package com.dolphin.soa.post.config;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.Collections;
import java.util.List;

@Configuration
public class WebConvertConfig implements WebMvcConfigurer {

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        MappingJackson2HttpMessageConverter jackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
        ObjectMapper objectMapper = new ObjectMapper();
        
        SimpleModule simpleModule = new SimpleModule();
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
        simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);
        objectMapper.registerModule(simpleModule);
        jackson2HttpMessageConverter.setObjectMapper(objectMapper);

        
        converters.add(new StringHttpMessageConverter());
        converters.add(jackson2HttpMessageConverter);
        converters.add(createEventStreamMessageConverter());
    }

    private HttpMessageConverter<Object> createEventStreamMessageConverter() {
        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
        converter.setSupportedMediaTypes(Collections.singletonList(MediaType.TEXT_EVENT_STREAM));
        return converter;
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("swagger-ui.html")
                .addResourceLocations("classpath:/META-INF/resources/");

        registry.addResourceHandler("/webjars/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/");
    }
}

seems did not work. what should I do to make the convert work without using EnableMvc annotation?

score 1 · Accepted Answer · answered May 25 '23 at 17:39

Using a Jackson2ObjectMapperBuilderCustomizer works for me, something like:

@Configuration
class JacksonLongConfig implements Jackson2ObjectMapperBuilderCustomizer {

    @Override
    public void customize(Jackson2ObjectMapperBuilder builder) {
        builder.serializerByType(Long.class, ToStringSerializer.instance);
    }
}

is it possible to convert long to string in spring boot rest api without using enablewebmvc annotation

1 Answers1