Spring MVC中前后台数据传输小结

前台向后台传递参数:

　　@ResponseBody
    @RequestMapping(value = "/findById/{id}", method = { RequestMethod.POST,
            RequestMethod.GET })
    public void findById(@PathVariable("id") Long id) {
        Person person=new Person();
        person.setId(id);
    }

　　访问地址为:项目地址+/findById/1.do

如果参数是一个对象bean:(@RequestBody注解帮助自动封装成bean,前台只需要传递格式正确的json)

    @ResponseBody
    @RequestMapping(value = "/findById", method = { RequestMethod.POST,
            RequestMethod.GET })
    public void findById(@RequestBody Person person) {
        person.setId(100);
    }

如果需要有返回值到前台:(普通bean或者list)

    @ResponseBody
    @RequestMapping(value = "/findById/{id}", method = { RequestMethod.POST,
            RequestMethod.GET })
    public Person findById(@PathVariable("id") Long id) {
        Person person=new Person();
        person.setId(id);
        return person;
    }

如果需要返回json,先进行配置,用的比较多的应该是下面两种:

    <bean id="fastJsonHttpMessageConverter"
        class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json;charset=UTF-8</value>
                <value>text/html;charset=UTF-8</value><!-- 避免IE出现下载JSON文件的情况 -->
            </list>
        </property>
        <property name="features">
            <array value-type="com.alibaba.fastjson.serializer.SerializerFeature">
                <value>WriteMapNullValue</value>
                <value>QuoteFieldNames</value>
                <value>DisableCircularReferenceDetect</value>
            </array>
        </property>
    </bean>

以及:

    <bean
        class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJacksonHttpMessageConverter" />
            </list>
        </property>
    </bean>
    <bean id="mappingJacksonHttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
            </list>
        </property>
    </bean>

代码示例:

    @ResponseBody
    @RequestMapping(value = "/findById/{id}", method = { RequestMethod.POST,
            RequestMethod.GET })
    public Map findById(@PathVariable("id") Long id) {
        Person person=new Person();
        person.setId(id);
        Map<String, Object> map = new HashedMap();
        map.put("total", "1");
        map.put("value", person);
        return map;
    }

附带mybatis的分页功能

maven包配置:

        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>3.7.3</version>
        </dependency>

service层分页代码示例:

    @Override
    public ResultBean findByParams(Person person,
            HttpServletRequest request) {
        int currentPage = Integer.parseInt(request.getParameter("page") == null ?"1":request.getParameter("page"));//当前页
        int pageSize    = Integer.parseInt(request.getParameter("rows")== null?"10":request.getParameter("rows"));//每页条数
        Page<?> page = PageHelper.startPage(currentPage, pageSize);
        List<Person> result=personDao.findByParams(person);
        Map<String,Object> resMap = new HashMap<String,Object>();
        resMap.put("rows",result);
        resMap.put("total",page.getTotal());
        ResultBean resultBean = new ResultBean();
        resultBean.setResultObj(resMap);
        return resultBean;
    }