Spring MVC 註解

URL路徑映射

• 這三個等價

@RequestMapping("/hello")
@RequestMapping("/hello.html")
@RequestMapping("hello")

• 可以配置多級路徑

@RequestMapping("/test/hello.html")
@RequestMapping("test/hello")

• 同一個方法可以配置多個路徑

@RequestMapping(value={"/test/hello.html","wow.html"})
@RequestMapping(path={"/test/hello.html","haha"})

• url映射可以使用通配* ，* 這裏可以填任意字符用來表示一級目錄，**匹配多級目錄，？匹配一個字符（示例中可填任意字符）

@RequestMapping("/*/hello.html")
@RequestMapping("/**/hello.html")
@RequestMapping("/**/*hello？")

窄化請求映射

@RequestMapping("/user")
@Controller
public class SecondController{}

//等價於
@RequestMapping("/user")
@Controller
public class SecondController{}

這倆的作用是在方法的url路徑之前增加/user

請求方法限定

@ RequestMapping(path = “/haha2”,method = RequestMethod.POST)
只處理POST請求

其他

• params的使用

    @RequestMapping(path = "/haha2",method = RequestMethod.GET,params = {"id"})
// http://localhost:8080/haha2?id

    @RequestMapping(path = "/haha2",method = RequestMethod.GET,params = {"id!=123"})
//http://localhost:8080/haha2?id=1234

    @RequestMapping(path = "/haha2",method = RequestMethod.GET,params = {"id=123","age=1234"})
//http://localhost:8080/haha2?id=123&age=1234

• 請求頭需要滿足的條件

    @RequestMapping(path = "/haha2",method = RequestMethod.GET,params = {"id=123","age=1234"},headers = "localhost")

Controller方法返回值

返回ModelAndView

• 我們之前的就是返回的ModelAndView

    @RequestMapping(path = "/haha2",method = RequestMethod.GET,params = {"id=123","age=1234"},headers = "localhost")
    public ModelAndView handleRequest(HttpServletRequest request) throws Exception {
        //模型和視圖
        ModelAndView mv = new ModelAndView();
        User user = new User();
        user.setUsername("苟利國家生死以");
        user.setPassword("豈因禍福避趨之");
        //把對象放進去了
        mv.addObject("user",user);
        //把視圖放進去了
        mv.setViewName("/index.jsp");
        return mv;
    }

void 方式（最原始的方式）

@RequestMapping(path = "/haha3")
    public void test(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("test");
        User user = new User();
        user.setId(1);
        user.setUsername("haha");
        user.setPassword("12345");
        request.setAttribute("user",user);
        request.getRequestDispatcher("WEB-INF/index.jsp").forward(request,response);
    }

返回字符串

• 表示以web根目錄作爲起點的路徑(絕對路徑)

    @RequestMapping(path = "/haha4")
    public String test2(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("test2");
        User user = new User();
        user.setId(1);
        user.setUsername("test2");
        user.setPassword("12345");
        request.setAttribute("user",user);
        return "/WEB-INF/index.jsp";
    }

• 表示以當前目錄作爲起點的路徑(相對路徑)

    @RequestMapping(path = "/haha5")
    public String test3(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println("test3");
        User user = new User();
        user.setId(1);
        user.setUsername("test3");
        user.setPassword("12345");
        request.setAttribute("user",user);
        return "index.jsp";
    }

可以用return返回WEB-INF下的資源

邏輯視圖

返回的字符串是物理視圖的一部分，完整的物理視圖這樣：

• 物理視圖名
  mv.setViewName(“/WEB-INF/userlist.jsp”);
• 頁面解析器注入兩個參數

<!--頁面解析器-->
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/"></property>
    <property name="suffix" value=".jsp"></property>
</bean>

• 之後返回的視圖名稱——邏輯視圖名：
  mv.setViewName(“userlist”);

返回字符串的時候model的返回

• request.setAttribute(“user”,user);
• model.addAttribute(“user”,user);

返回字符串的時候可以轉發（默認實現）

• return “forword:/haha/index.jsp”;

返回字符串的時候可以重定向

• return “redirect:/haha/index.jsp”;