spring boot 規范json返回值

spring boot 接口返回配置 @ResponseBody ，則返回自定義的對象，解析成json。
但是,部分字段能友好的展示出來。如 Date，Long。Date必須手動格式化，才能輸出想要的格式，還要注意時區問題。Long類型，相對過長的Long類型，會進行四舍五入等處理，失去准確性。

如Date類型處理需要給屬性值加上注解：

    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")

Long類型配置和其他配置，可以交給以下代碼解決

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import java.math.BigDecimal;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
import org.springframework.context.annotation.Bean;
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.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

/**
 * web配置
 *
 * @author
 * @date 2017-08-23 15:48
 */
@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {
    @Bean
    public MappingJackson2HttpMessageConverter getMappingJackson2HttpMessageConverter() {
        MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
        //設置日期格式
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

        /**
         * 序列換成json時,將所有的long變成string
         * 因為js中得數字類型不能包含所有的java long值
         */
        SimpleModule simpleModule = new SimpleModule();
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
        simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);
        simpleModule.addSerializer(BigDecimal.class, ToStringSerializer.instance);
        objectMapper.registerModule(simpleModule);
        mappingJackson2HttpMessageConverter.setObjectMapper(objectMapper);

        //設置中文編碼格式
//        List<MediaType> list = new ArrayList<MediaType>();
//        list.add(MediaType.APPLICATION_JSON_UTF8);
//        mappingJackson2HttpMessageConverter.setSupportedMediaTypes(list);
        return mappingJackson2HttpMessageConverter;
    }

    @Bean
    public StringHttpMessageConverter getStringHttpMessageConverter() {

        StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter(Charset.forName("GBK"));

        //設置中文編碼格式
        List<MediaType> list = new ArrayList<MediaType>();
        list.add(MediaType.APPLICATION_XML);
        stringHttpMessageConverter.setSupportedMediaTypes(list);
        return stringHttpMessageConverter;
    }

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        List<HttpMessageConverter<?>> convertersList = new HttpMessageConverters().getConverters();
        for(int i = 0; i < convertersList.size(); i++){
            if(convertersList.get(i) instanceof MappingJackson2HttpMessageConverter){
                converters.add(getMappingJackson2HttpMessageConverter());
            }else if(convertersList.get(i) instanceof StringHttpMessageConverter){
                converters.add(getStringHttpMessageConverter());
            }else{
                converters.add(convertersList.get(i));
            }
        }
    }

}