默認情況下，springMVC的@ResponseBody返回的是String類型，如果返回其他類型則會報錯。
使用fastjson的情況下，在springmvc.xml配置里加入：
<mvc:annotation-driven>
<mvc:message-converters
register-defaults="true">
<bean
class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html;charset=UTF-8</value>
<value>application/json</value>
<value>application/xml;charset=UTF-8</value>
</list>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
在pom.xml引入依賴：
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.7.3</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.7.3</version>
</dependency>