第一步: pom.xml 中刪除預設的 jackson

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <exclusions>
        <exclusion>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId
 
>jackson-databind</artifactId>
        </exclusion>
    </exclusions>
</dependency>

第二步: pom.xml 中引用fastjson

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.45</version>
</dependency
 
>

第三步: 啟動類中配置

@SpringBootApplication  //申明讓spring boot自動給程式進行必要的配置
public class AppStart extends WebMvcConfigurerAdapter {

    public static void main(String[] args) {
        SpringApplication.run(AppStart.class, args);
    }

    /**
     * 替換框架json為fastjson
     */
    @Override
    public void
 
 configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        super.configureMessageConverters(converters);
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.PrettyFormat, 
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.WriteNullNumberAsZero, 
                SerializerFeature.WriteNullStringAsEmpty
            );
        // 處理中文亂碼問題
        List<MediaType> fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        fastConverter.setSupportedMediaTypes(fastMediaTypes);
        fastConverter.setFastJsonConfig(fastJsonConfig);

        //處理字串, 避免直接返回字串的時候被添加了引號
        StringHttpMessageConverter smc = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        converters.add(smc);

        converters.add(fastConverter);
    }
}