SpringMvc切换Json转换工具的操作代码

<!-- gson依赖 -->
<dependency>
	<groupId>com.google.code.gson</groupId>
	<artifactId>gson</artifactId>
</dependency>

@Configuration
public class JsonWebConfig {
    @Bean
    public GsonHttpMessageConverter gsonHttpMessageConverter() {
        return new GsonHttpMessageConverter();
    }
}

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>

        User user = new User();
        user.setName("lisi");
        user.setAge(18);
        //使用json的转换工具
        ObjectMapper objectMapper = new ObjectMapper();
        String json = objectMapper.writeValueAsString(user);
        return json;

<!--    配置处理器映射器-->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
            </list>
        </property>
    </bean>

        User user = new User();
        user.setName("lisi");
        user.setAge(18);
        return user;

<!--    mvc的注解驱动-->
    <mvc:annotation-driven/>