springmvc02，使用註解
unit04_01
a.RequestMappingHandlerMapping組件
@RequestMapping("/login.do")
該標記用在Controller業務方法前
b.Controller編寫和配置
取消了實現Controller接口及方法的約定，可以允許程序猿按需要靈活定義業務方法.
Controller需要掃描到Spring容器，[email protected]
public ModelAndView或者String 方法名(根據需要定義request，session,response)
例子：
public String execute(){
return "hello";
}
public ModelAndView execute(){
ModelAndView mav=new ModelAndView();
mav.getModel().put("msg", "模型數據");//等價於request.setAttribute("msg","data");
return "hello";
}
流程：
-->DispatcherServlet
-->HandlerMapping
-->HelloController
-->ViewResolver
-->hello.jsp
完整代碼：
spring xml：
<mvc:annotation-driven/>
<!-- 掃描controller -->
<context:component-scan base-package="org.alexhe"></context:component-scan>
<!-- 配置viewResolver -->
<bean id="viewresolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
web.xml:
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
HelloController.java:
package org.alexhe.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HelloController {
@RequestMapping("/hello.do")
public ModelAndView execute(){
ModelAndView mav=new ModelAndView();
mav.setViewName("hello");
mav.getModel().put("msg", "我是一個msg");
return mav;
}
}
hello.jsp:
<h2>springmvc註解版,${msg}</h2>
unit04_02
進入登陸頁面
/tologin.do
-->DispatcherServlet
-->Handlermapping
-->Logincontroller.toLogin
-->ViewResolver
-->login.jsp
/login.do
-->DispatcherServlet
-->Handlermapping
-->Logincontroller.checkLogin
-->ViewResolver
-->錯誤login.jsp,正確ok.jsp
完整代碼：
login.jsp:
<form action="login.do" method="post">
用戶名:<input type="text" name="username"><br>
密碼:<input type="password" name="password"><br>
<input type="submit" value="登陸">
</form>
LoginController:
package org.alexhe.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class LoginController {
@RequestMapping("/tologin.do")
public String toLogin(){
return "login";//返回視圖名稱
}
@RequestMapping("/login.do")
public String checkLogin(HttpServletRequest request){
//獲取請求信息
String name=request.getParameter("username");
String password=request.getParameter("password");
if("root".equals(name)&&"1234".equals(password)){
return "ok";
}else{
return "login";
}
}
}
1.如何接受請求參數
a。利用HttpServletRequest
b。利用業務方法參數
--參數名與請求參數key保持一致，public String f1(String username,String password)
[email protected]("key")，public String f1(@RequestParam("username")String name,@RequestParam("password")String pass)//前臺jsp傳過來的是username和password
c。利用實體對象參數
使用建議：少量參數用b。大量參數用c。遇到非字符串類型參數建議使用a。
例子：
@RequestMapping("/login1.do")
public String checkLogin1(String username,String password){
System.out.println("執行checklong1方法");
System.out.println("username:"+username);
System.out.println("password:"+password);
return "login";
}
@RequestMapping("/login2.do")
public String checkLogin2(@RequestParam("username")String name,@RequestParam("password")String passw){
System.out.println("執行checklong2方法");
System.out.println("username:"+name);
System.out.println("password:"+pass);
return "login";
}
//測試用實體對象接收請求參數,前臺jsp不需要像struts一樣改成user.username。還是用username和password
@RequestMapping("/login2.do")
public String checkLogin2(User user){
System.out.println("執行checklong2方法");
System.out.println(user.getUsername());
return "login";
}
2.Controller如何向相應jsp傳值
a。利用HttpServletRequest
b。利用ModelAndView做返回值
c。利用ModelMap方法參數
[email protected]("key")
c的例子：
@RequestMapping("/login3.do")
public String checkLogin3(String username,String password,ModelMap model){
if("root".equals(username)&&"1234".equals(password)){
model.put("user", username);
return "ok";
}else{
model.put("msg","用戶名密碼錯誤");
return "login";
}
}
3.Controller如何使用Session
--
public String checkLogin(HttpServletRequest request){
}
或者幹脆直接加HttpSession
public String checkLogin(HttpSession session){
}
例子：
@RequestMapping("/login3.do")
public String checkLogin3(String username,String password,ModelMap model,HttpSession session){
}
案例：列表顯示功能
/list.do
-->DispatcherServlet
-->Handlermapping
-->ListController,傳遞到list.jsp
-->ViewResolver
-->/WEB-INF/list.jsp
springmvc02，使用註解