SpringMVC返回JSON字符串

1. 在controller层的方法上加上@ResponseBody注解

    @GetMapping("/selectOne")
    @ResponseBody
    public LabMsg selectOne(Integer labNum) {

        LabMsg labMsg = labMsgService.queryById(labNum);
        System.out.println(labMsg);
        return labMsg;
    }

2. 在pom.xml引入依赖

    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.47</version>
    </dependency>

3. 在springmvc.xml中加入如下代码

<mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                <property name="supportedMediaTypes" value="application/json"/>
                <property name="features">
                    <array>
                        <value>WriteMapNullValue</value>
                        <value>WriteDateUseDateFormat</value>
                    </array>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

4. 效果图