spring mvc框架

Spring框架提供了构造Web应用程序的全能MVC模块。Spring MVC分离了控制器、模型对象、分派器以及处理程序对象的角色，这种分离让它们更容易进行制定。是一个标准的MVC框架。

那你猜一猜哪一部分应该是哪一部分？

SpringMVC框架图

SpringMVC接口解释

DispatcherServlet接口：

Spring提供的前端控制器，所有的请求都有经过它来统一分发。在DispatcherServlet将请求分发给Spring Controller之前，需要借助于Spring提供的HandlerMapping定位到具体的Controller。

HandlerMapping接口：

能够完成客户请求到Controller映射。

Controller接口：

需要为并发用户处理上述请求，因此实现Controller接口时，必须保证线程安全并且可重用。Controller将处理用户请求，这和Struts Action扮演的角色是一致的。一旦Controller处理完用户请求，则返回ModelAndView对象给DispatcherServlet前端控制器，ModelAndView中包含了模型（Model）和视图（View）。从宏观角度考虑，DispatcherServlet是整个Web应用的控制器；从微观考虑，Controller是单个Http请求处理过程中的控制器，而ModelAndView是Http请求过程中返回的模型（Model）和视图（View）。

ViewResolver接口：

Spring提供的视图解析器（ViewResolver）在Web应用中查找View对象，从而将相应结果渲染给客户。

SpringMVC运行原理

1.客户端请求提交到DispatcherServlet

2.由DispatcherServlet控制器查询一个或多个HandlerMapping，找到处理请求的Controller

3.DispatcherServlet将请求提交到Controller

4.Controller调用业务逻辑处理后，返回ModelAndView

5.DispatcherServlet查询一个或多个ViewResoler视图解析器，找到ModelAndView指定的视图

6.视图负责将结果显示到客户端

SpringMVC运行实例

Account类：

Java代码

1. package com.pb.entity;
3. publicclass Account {
4. private String cardNo;
5. private String password;
6. privatefloat balance;
7. public String getCardNo() {
8. return cardNo;
9. }
10. publicvoid setCardNo(String cardNo) {
11. this.cardNo = cardNo;
12. }
13. public String getPassword() {
14. return password;
15. }
16. publicvoid setPassword(String password) {
17. this.password = password;
18. }
19. publicfloat getBalance() {
20. return balance;
21. }
22. publicvoid setBalance(float balance) {
23. this.balance = balance;
24. }
26. }

LoginController类：

Java代码

1. package com.pb.web.controller;
3. import java.util.HashMap;
4. import java.util.Map;
6. import javax.servlet.http.HttpServletRequest;
7. import javax.servlet.http.HttpServletResponse;
9. import org.springframework.web.servlet.ModelAndView;
10. import org.springframework.web.servlet.mvc.AbstractController;
12. import com.pb.entity.Account;
14. publicclass LoginController extends AbstractController {
15. private String successView;
16. private String failView;//这两个参数是返回值传给applicationContext.xml，进行页面分配
18. public String getSuccessView() {
19. return successView;
20. }
21. publicvoid setSuccessView(String successView) {
22. this.successView = successView;
23. }
24. public String getFailView() {
25. return failView;
26. }
27. publicvoid setFailView(String failView) {
28. this.failView = failView;
29. }
30. @Override
31. protected ModelAndView handleRequestInternal(HttpServletRequest request,
32. HttpServletResponse response) throws Exception {
33. // TODO Auto-generated method stub
34. String cardNo=request.getParameter("cardNo");
35. String password=request.getParameter("password");
36. Account account =getAccount(cardNo,password);
37. Map<String ,Object> model=new HashMap<String,Object>();
38. if(account !=null){
39. model.put("account", account);
40. returnnew ModelAndView(getSuccessView(),model);
41. }else{
42. model.put("error", "卡号和密码不正确");
43. returnnew ModelAndView(getFailView(),model);
44. }
45. }//本应该这个方法写在模型层，这地方直接给放在了逻辑层这个地方偷懒了。
46. public Account getAccount(String cardNo,String password){
47. if(cardNo.equals("123")&&password.equals("123")){
48. Account account =new Account();
49. account.setCardNo(cardNo);
50. account.setBalance(88.8f);
51. return account;
52. }else{
53. returnnull;
54. }
55. }
57. }

applicationContext.xml

Html代码

1. <?xmlversion="1.0" encoding="UTF-8"?>
3. <beansxmlns="http://www.springframework.org/schema/beans"
4. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
5. xmlns:aop="http://www.springframework.org/schema/aop"
6. xmlns:tx="http://www.springframework.org/schema/tx"
7. xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
8. http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
9. http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">
10. <beanid="loginController"class="com.pb.web.controller.LoginController">
11. <propertyname="successView"value="showAccount"></property>
12. <propertyname="failView" value="login"></property>
13. </bean>
14. <beanid="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
15. <propertyname="mappings">
16. <props>
17. <propkey="/login.do">loginController</prop>
18. </props>
19. </property>
20. </bean>
21. <beanid="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
22. <propertyname="prefix" value="/"></property>
23. <propertyname="suffix" value=".jsp"></property>
24. </bean>
25. </beans>

Jsp页面：

Html代码

1. <%@ pagelanguage="java" contentType="text/html; charset=GB18030"
2. pageEncoding="GB18030"%>
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4. <html>
5. <head>
6. <metahttp-equiv="Content-Type"content="text/html; charset=GB18030">
7. <title>Insert title here</title>
8. </head>
9. <body>
10. <ahref="login.jsp">进入</a>
12. </body>
13. </html>

login.jsp

Html代码

1. <%@ pagelanguage="java" contentType="text/html; charset=GB18030"
2. pageEncoding="GB18030"%>
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4. <html>
5. <head>
6. <metahttp-equiv="Content-Type"content="text/html; charset=GB18030">
7. <title>Insert title here</title>
8. </head>
9. <body>
10. ${error }
11. <formaction="login.do" method="post">
12. 账号登陆<br>
13. <hr>
14. 卡号：<inputtype="text" name="cardNo"><br>
15. 密码：<inputtype="text" name="password"><br>
16. <inputtype="submit" value="登陆">
17. </form>
19. </body>
20. </html>

showAccount.jsp

Html代码

1. <%@ pagelanguage="java" contentType="text/html; charset=GB18030"
2. pageEncoding="GB18030"%>
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4. <html>
5. <head>
6. <metahttp-equiv="Content-Type"content="text/html; charset=GB18030">
7. <title>Insert title here</title>
8. </head>
9. <body>
10. 账户信息<br>
11. 卡号：${account.cardNo }<br>
12. 密码：${account.password }<br>
13. 钱数：${account.balance }<br>
14. </body>
15. </html>

Web.xml

Html代码

1. <?xmlversion="1.0" encoding="UTF-8"?>
2. <web-appxmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3. xmlns="http://java.sun.com/xml/ns/j2ee"
4. xmlns:javaee="http://java.sun.com/xml/ns/javaee"
5. xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"version="2.4">
6. <welcome-file-list>
7. <welcome-file>index.jsp</welcome-file>
8. </welcome-file-list>
9. <servlet>
10. <servlet-name>Dispatcher</servlet-name>
11. <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
12. <init-param>
13. <param-name>contextConfigLocation</param-name>
14. <param-value>classpath:applicationContext.xml</param-value>
15. </init-param>
16. </servlet>
17. <servlet-mapping>
18. <servlet-name>Dispatcher</servlet-name>
19. <url-pattern>*.do</url-pattern>
20. </servlet-mapping>
21. </web-app>