SpringMVC 清晰簡單教程

jopen 10年前發布 | 97K 次閱讀 SpringMVC Spring MVC Web框架

Spring MVC 背景介紹

Spring 框架提供了構建 Web 應用程序的全功能 MVC 模塊。使用 Spring 可插入的 MVC 架構，可以選擇是使用內置的 Spring Web 框架還是 Struts 這樣的 Web 框架。通過策略接口，Spring 框架是高度可配置的，而且包含多種視圖技術，例如 JavaServer Pages（JSP）技術、Velocity、Tiles、iText 和 POI。Spring MVC 框架并不知道使用的視圖，所以不會強迫您只使用 JSP 技術。Spring MVC 分離了控制器、模型對象、分派器以及處理程序對象的角色，這種分離讓它們更容易進行定制。

常見MVC框架比較

運行性能上：

Jsp+servlet>struts1>spring mvc>struts2+freemarker>>struts2,ognl,值棧。

開發效率上,基本正好相反。值得強調的是，spring mvc開發效率和struts2不相上下。

Struts2的性能低的原因是因為OGNL和值棧造成的。所以，如果你的系統并發量高，可以使用freemaker進行顯示，而不是采用OGNL和值棧。這樣，在性能上會有相當大得提高。

基于spring2.5的采用XML配置的spring MVC項目

注：本項目全部基于XML配置。同時，集成了hibernate。采用的是：spring MVC+hibernate+spring的開發架構。

1. 建立web項目

2. 導入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包為hibernate相關jar包)

3. 修改web.xml如下：

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">>

<servlet-name>dispatcherServlet</servlet-name>

<servlet-class>

org.springframework.web.servlet.DispatcherServlet

</servlet-class>

<init-param>

<param-name>contextConfigLocation</param-name>

<param-value>/WEB-INF/hib-config.xml,/WEB-INF/web-config.xml,/WEB-INF/service-config.xml,/WEB-INF/dao-config.xml</param-value>

</init-param>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>dispatcherServlet</servlet-name>

<url-pattern>*.do</url-pattern>

</servlet-mapping>

</web-app>

4. 增加web-config.xml(這里包含spring mvc相關的相關配置)

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

<bean id="paraMethodResolver"

class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver">

</bean>

<bean id="viewResolver"

class="org.springframework.web.servlet.view.InternalResourceViewResolver">

<property name="viewClass"

value="org.springframework.web.servlet.view.JstlView"/>

</bean>

<bean id="urlMapping"

class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">

<props>

<prop key="user.do">userController</prop>

</props>

</property>

</bean>

</bean>

</beans>

5. 在WEB-INF下增加service-config.xml(這里包含service層類的相關配置)

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

</bean>

</beans>

6. 在WEB-INF下增加hib-config.xml(這里包含spring集成hibernate相關的配置)

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xmlns:tx="http://www.springframework.org/schema/tx"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx-2.5.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-2.5.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-2.5.xsd

<context:component-scan base-package="com.sxt"/>

<aop:aspectj-autoproxy />

<bean id="dataSource"

class="org.apache.commons.dbcp.BasicDataSource">

<property name="driverClassName"

value="com.mysql.jdbc.Driver">

</property>

</bean>

<bean id="sessionFactory"

class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">

</property>

<props>

org.hibernate.dialect.MySQLDialect

</prop>

<prop key="hibernate.hbm2ddl.auto">update</prop>

</props>

</property>

</property>

</bean>

</bean>

</bean>

</bean>

<tx:annotation-driven transaction-manager="txManager" />

<aop:config>

<aop:pointcut expression="execution(public * com.sxt.service.impl.*.*(..))" id="businessService"/>

<aop:advisor advice-ref="txAdvice" pointcut-ref="businessService" />

</aop:config>

<tx:advice id="txAdvice" transaction-manager="txManager" >

<tx:attributes>

<tx:method name="find*" read-only="true" propagation="NOT_SUPPORTED" />

<!-- get開頭的方法不需要在事務中運行。

有些情況是沒有必要使用事務的，比如獲取數據。開啟事務本身對性能是有一定的影響的-->

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

7. 在WEB-INF下增加dao-config.xml(這里包含dao層類的相關配置)

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

</bean>

</beans>

8. 建立相關類和包結構，如下圖所示：

9. 各類代碼如下：

package com.sxt.po;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

@Entity

public class User {

@Id

@GeneratedValue(strategy=GenerationType.AUTO)

private int id;

private String uname;

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getUname() {

return uname;

}

public void setUname(String uname) {

this.uname = uname;

}

package com.sxt.dao;

import org.springframework.orm.hibernate3.HibernateTemplate;

import com.sxt.po.User;

public class UserDao {

private HibernateTemplate hibernateTemplate;

public void add(User u){

System.out.println("UserDao.add()");

hibernateTemplate.save(u);

}

public HibernateTemplate getHibernateTemplate() {

return hibernateTemplate;

}

public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {

this.hibernateTemplate = hibernateTemplate;

}

package com.sxt.service;

import com.sxt.dao.UserDao;

import com.sxt.po.User;

public class UserService {

private UserDao userDao;

public void add(String uname){

System.out.println("UserService.add()");

User u = new User();

u.setUname(uname);

userDao.add(u);

}

public UserDao getUserDao() {

return userDao;

}

public void setUserDao(UserDao userDao) {

this.userDao = userDao;

}

package com.sxt.action;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.mvc.Controller;

import com.sxt.service.UserService;

public class UserController implements Controller {

private UserService userService;

@Override

public ModelAndView handleRequest(HttpServletRequest req,

HttpServletResponse resp) throws Exception {

System.out.println("HelloController.handleRequest()");

req.setAttribute("a", "aaaa");

userService.add(req.getParameter("uname"));

return new ModelAndView("index");

}

public UserService getUserService() {

return userService;

}

public void setUserService(UserService userService) {

this.userService = userService;

}

10. 運行測試：

http://locahost:8080/springmvc01/user.do?uname=zhangsan。

結果：數據庫中增加zhangsan的記錄。頁面跳轉到index.jsp上，顯示：

基于spring2.5注解實現的spring MVC項目

我們采用sprng MVC開發項目時，通常都會采用注解的方式，這樣可以大大提高我們的開發效率。實現零配置。下面我們從零開始重新做一個spring MVC的配置。這個項目完全采用注解的方式開發。同時，我們以后的spring MVC項目也都會采用注解的方式。

1. 建立web項目

2. 導入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包為hibernate相關jar包)

3. 修改web.xml，文件內容如下：

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<servlet-name>springmvc</servlet-name>

<servlet-class>

org.springframework.web.servlet.DispatcherServlet

</servlet-class>

<init-param>

<param-name>contextConfigLocation</param-name>

<param-value>/WEB-INF/hib-config.xml,/WEB-INF/springmvc-servlet.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>

</web-app>

4. springmvc-servlet.xml配置內容如下：

<?xml version="1.0" encoding="UTF-8"?>

<beans

xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:p="http://www.springframework.org/schema/p"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-2.5.xsd">

<context:component-scan base-package="com.sxt"/>

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"

p:suffix=".jsp"/>

</beans>

5. hib-config.xml(配置了spring集成hibernate)

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xmlns:tx="http://www.springframework.org/schema/tx"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx-2.5.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-2.5.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-2.5.xsd

<context:component-scan base-package="com.sxt"/>

<aop:aspectj-autoproxy />

<bean id="dataSource"

class="org.apache.commons.dbcp.BasicDataSource">

<property name="driverClassName"

value="com.mysql.jdbc.Driver">

</property>

</bean>

<bean id="sessionFactory"

class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">

</property>

<props>

org.hibernate.dialect.MySQLDialect

</prop>

<prop key="hibernate.hbm2ddl.auto">update</prop>

</props>

</property>

</property>

</bean>

</bean>

</bean>

</bean>

<tx:annotation-driven transaction-manager="txManager" />

<aop:config>

<aop:pointcut expression="execution(public * com.sxt.service.impl.*.*(..))" id="businessService"/>

<aop:advisor advice-ref="txAdvice" pointcut-ref="businessService" />

</aop:config>

<tx:advice id="txAdvice" transaction-manager="txManager" >

<tx:attributes>

<tx:method name="find*" read-only="true" propagation="NOT_SUPPORTED" />

<!-- get開頭的方法不需要在事務中運行。

有些情況是沒有必要使用事務的，比如獲取數據。開啟事務本身對性能是有一定的影響的-->

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

6. WEB-INF下建立jsp文件夾，并且將index.jsp放入該文件夾下。Index.jsp的內容如下：

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>My JSP 'index.jsp' starting page</title>

<!--

-->

</head>

<body>

<h1>**********${params.uname}</h1>

<h1>**********${requestScope.u}</h1>

<h1>**********${requestScope.user}</h1>

</body>

</html>

7. 建立整個項目的包結構和相關類。如下圖所示：

8. User、UserDao、UserService、UserController類的代碼如下：

package com.sxt.po;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

@Entity

public class User {

@Id

@GeneratedValue(strategy=GenerationType.AUTO)

private int id;

private String uname;

private String pwd;

public String getPwd() {

return pwd;

}

public void setPwd(String pwd) {

this.pwd = pwd;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getUname() {

return uname;

}

public void setUname(String uname) {

this.uname = uname;

}

package com.sxt.dao;

import javax.annotation.Resource;

import org.springframework.orm.hibernate3.HibernateTemplate;

import org.springframework.stereotype.Repository;

import com.sxt.po.User;

@Repository("userDao")

public class UserDao {

@Resource

private HibernateTemplate hibernateTemplate;

public void add(User u){

System.out.println("UserDao.add()");

hibernateTemplate.save(u);

}

public HibernateTemplate getHibernateTemplate() {

return hibernateTemplate;

}

public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {

this.hibernateTemplate = hibernateTemplate;

}

package com.sxt.service;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.sxt.dao.UserDao;

import com.sxt.po.User;

@Service("userService")

public class UserService {

@Resource

private UserDao userDao;

public void add(String uname){

System.out.println("UserService.add()");

User u = new User();

u.setUname(uname);

userDao.add(u);

}

public UserDao getUserDao() {

return userDao;

}

public void setUserDao(UserDao userDao) {

this.userDao = userDao;

}

package com.sxt.web;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.SessionAttributes;

import com.sxt.po.User;

import com.sxt.service.UserService;

@Controller("userController")

@RequestMapping("/user.do")

public class UserController {

@Resource

private UserService userService;

@RequestMapping(params="method=reg")

public String reg(String uname) {

System.out.println("HelloController.handleRequest()");

userService.add(uname);

return "index";

}

public UserService getUserService() {

return userService;

}

public void setUserService(UserService userService) {

this.userService = userService;

}

9. 運行測試：

http://pc-201110291327:8080/springmvc02/user.do?method=reg&uname=gaoqi

則會調用userController的reg方法，從而將數據內容插入到數據庫中。

基于spring 3.0項目開發實例

spring3.0完全兼容spring2.5.因此，我們只要簡單修改上面項目的類庫和配置文件。類的代碼保持不變。

1. 導入相關jar包，如下：

2. spring配置文件springmvc-servlet.xml修改如下：

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:p="http://www.springframework.org/schema/p"

xmlns:mvc="http://www.springframework.org/schema/mvc"

xmlns:context="http://www.springframework.org/schema/context"

xmlns:util="http://www.springframework.org/schema/util"

xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd

http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd

http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">

<context:component-scan base-package="com.sxt.web"/>

<mvc:annotation-driven />

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"

p:prefix="/WEB-INF/jsp/" p:suffix=".jsp">

</bean>

</beans>

3. spring配置文件hib-config.xml內容修改如下：

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xmlns:tx="http://www.springframework.org/schema/tx"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx-3.0.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-3.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-3.0.xsd

<context:component-scan base-package="com.sxt"/>

<aop:aspectj-autoproxy />

<bean id="dataSource"

class="org.apache.commons.dbcp.BasicDataSource">

<property name="driverClassName"

value="com.mysql.jdbc.Driver">

</property>

</bean>

<bean id="sessionFactory"

class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">

</property>

<props>

org.hibernate.dialect.MySQLDialect

</prop>

<prop key="hibernate.hbm2ddl.auto">update</prop>

</props>

</property>

</property>

</bean>

</bean>

</bean>

</bean>

<tx:annotation-driven transaction-manager="txManager" />

<aop:config>

<aop:pointcut expression="execution(public * com.sxt.service.impl.*.*(..))" id="businessService"/>

<aop:advisor advice-ref="txAdvice" pointcut-ref="businessService" />

</aop:config>

<tx:advice id="txAdvice" transaction-manager="txManager" >

<tx:attributes>

<tx:method name="find*" read-only="true" propagation="NOT_SUPPORTED" />

<!-- get開頭的方法不需要在事務中運行。

有些情況是沒有必要使用事務的，比如獲取數據。開啟事務本身對性能是有一定的影響的-->

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

4. web.xml文件不變

5. 類的代碼不變。

6. 運行，測試。跟上一個項目保持一致。

Spring MVC 3.0 深入

核心原理

1. 用戶發送請求給服務器。url：user.do

2. 服務器收到請求。發現 DispatchServlet可以處理。于是調用DispatchServlet。

3. DispatchServlet內部，通過 HandleMapping檢查這個url有沒有對應的Controller。如果有，則調用Controller。

4. Controller開始執行。

5. Controller執行完畢后，如果返回字符串，則ViewResolver將字符串轉化成相應的視圖對象；如果返回ModelAndView對象，該對象本身就包含了視圖對象信息。

6. DispatchServlet將執視圖對象中的數據，輸出給服務器。

7. 服務器將數據輸出給客戶端。

spring3.0中相關jar包的含義

org.springframework.aop-3.0.3.RELEASE.jar	spring的aop面向切面編程
org.springframework.asm-3.0.3.RELEASE.jar	spring獨立的asm字節碼生成程序
org.springframework.beans-3.0.3.RELEASE.jar	IOC的基礎實現
org.springframework.context-3.0.3.RELEASE.jar	IOC基礎上的擴展服務
org.springframework.core-3.0.3.RELEASE.jar	spring的核心包
org.springframework.expression-3.0.3.RELEASE.jar	spring的表達式語言
org.springframework.web-3.0.3.RELEASE.jar	web工具包
org.springframework.web.servlet-3.0.3.RELEASE.jar	mvc工具包

@Controller控制器定義

和Struts1一樣，Spring的Controller是Singleton的。這就意味著會被多個請求線程共享。因此，我們將控制器設計成無狀態類。

在spring 3.0中，通過@controller標注即可將class定義為一個controller類。為使spring能找到定義為controller的bean,需要在spring-context配置文件中增加如下定義：

<context:component-scan base-package="com.sxt.web"/>

注：實際上，使用@component，也可以起到@Controller同樣的作用。

@RequestMapping

在類前面定義，則將url和類綁定。

在方法前面定義，則將url和類的方法綁定，如下所示：

package com.sxt.web;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import com.sxt.service.UserService;

@Controller

@RequestMapping("/user.do")

public class UserController {

@Resource

private UserService userService;

//http://localhost:8080/springmvc02/user.do?method=reg&uname=zzzz

@RequestMapping(params="method=reg")

public String reg(String uname) {

System.out.println("HelloController.handleRequest()");

userService.add(uname);

return "index";

}

public UserService getUserService() {

return userService;

}

public void setUserService(UserService userService) {

this.userService = userService;

}

@RequestParam

一般用于將指定的請求參數付給方法中形參。示例代碼如下：

@RequestMapping(params="method=reg5")

public String reg5(@RequestParam("name")String uname,ModelMap map) {

System.out.println("HelloController.handleRequest()");

System.out.println(uname);

return "index";

}

這樣，就會將name參數的值付給uname。當然，如果請求參數名稱和形參名稱保持一致，則不需要這種寫法。

@SessionAttributes

將ModelMap中指定的屬性放到session中。示例代碼如下：

@Controller

@RequestMapping("/user.do")

@SessionAttributes({"u","a"}) //將ModelMap中屬性名字為u、a的再放入session中。這樣，request和session中都有了。

public class UserController {

@RequestMapping(params="method=reg4")

public String reg4(ModelMap map) { System.out.println("HelloController.handleRequest()");

map.addAttribute("u","uuuu"); //將u放入request作用域中，這樣轉發頁面也可以取到這個數據。

return "index";

}

<body>

<h1>**********${requestScope.u.uname}</h1>

<h1>**********${sessionScope.u.uname}</h1>

</body>

注：名字為”user”的屬性再結合使用注解@SessionAttributes可能會報錯。

@ModelAttribute

這個注解可以跟@SessionAttributes配合在一起用。可以將ModelMap中屬性的值通過該注解自動賦給指定變量。

示例代碼如下：

package com.sxt.web;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.ModelAttribute;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.SessionAttributes;

@Controller

@RequestMapping("/user.do")

@SessionAttributes({"u","a"})

public class UserController {

@RequestMapping(params="method=reg4")

public String reg4(ModelMap map) {

System.out.println("HelloController.handleRequest()");

map.addAttribute("u","尚學堂高淇");

return "index";

}

@RequestMapping(params="method=reg5")

public String reg5(@ModelAttribute("u")String uname,ModelMap map) {

System.out.println("HelloController.handleRequest()");

System.out.println(uname);

return "index";

}

先調用reg4方法，再調用reg5方法。我們發現控制臺打印出來：尚學堂高淇

Controller類中方法參數的處理

Controller類中方法返回值的處理

1. 返回string(建議)

a) 根據返回值找對應的顯示頁面。路徑規則為：prefix前綴+返回值+suffix后綴組成

b) 代碼如下：

@RequestMapping(params="method=reg4")

public String reg4(ModelMap map) {

System.out.println("HelloController.handleRequest()");

return "index";

}

前綴為：/WEB-INF/jsp/ 后綴是：.jsp

在轉發到：/WEB-INF/jsp/index.jsp

2. 也可以返回ModelMap、ModelAndView、map、List、Set、Object、無返回值。一般建議返回字符串！

請求轉發和重定向

代碼示例：

package com.sxt.web;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.ModelAttribute;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.SessionAttributes;

@Controller

@RequestMapping("/user.do")

public class UserController {

@RequestMapping(params="method=reg4")

public String reg4(ModelMap map) {

System.out.println("HelloController.handleRequest()");

//return "forward:index.jsp";

//return "forward:user.do?method=reg5"; //轉發

//return "redirect:user.do?method=reg5"; //重定向

return "redirect:http://www.baidu.com"; //重定向

}

@RequestMapping(params="method=reg5")

public String reg5(String uname,ModelMap map) {

System.out.println("HelloController.handleRequest()");

System.out.println(uname);

return "index";

}

訪問reg4方法，既可以看到效果。

獲得request對象、session對象

普通的Controller類，示例代碼如下：

@Controller

@RequestMapping("/user.do")

public class UserController {

@RequestMapping(params="method=reg2")

public String reg2(String uname,HttpServletRequest req,ModelMap map){

req.setAttribute("a", "aa");

req.getSession().setAttribute("b", "bb");

return "index";

}

ModelMap

是map的實現，可以在其中存放屬性，作用域同request。下面這個示例，我們可以在modelMap中放入數據，然后在forward的頁面上顯示這些數據。通過el表達式、JSTL、java代碼均可。代碼如下：

package com.sxt.web;

import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.servlet.mvc.multiaction.MultiActionController;

@Controller

@RequestMapping("/user.do")

public class UserController extends MultiActionController {

@RequestMapping(params="method=reg")

public String reg(String uname,ModelMap map){

map.put("a", "aaa");

return "index";

}

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<body>

<h1>${requestScope.a}</h1>

<c:out value="${requestScope.a}"></c:out>

</body>

</html>

ModelAndView模型視圖類

見名知意，從名字上我們可以知道ModelAndView中的Model代表模型，View代表視圖。即，這個類把要顯示的數據存儲到了Model屬性中，要跳轉的視圖信息存儲到了view屬性。我們看一下ModelAndView的部分源碼，即可知其中關系：

public class ModelAndView {

/** View instance or view name String */

private Object view;

/** Model Map */

private ModelMap model;

/**

* Indicates whether or not this instance has been cleared with a call to {@link #clear()}.

private boolean cleared = false;

/**

* Default constructor for bean-style usage: populating bean

* properties instead of passing in constructor arguments.

* @see #setView(View)

* @see #setViewName(String)

public ModelAndView() {

}

/**

* Convenient constructor when there is no model data to expose.

* Can also be used in conjunction with <code>addObject</code>.

* @param viewName name of the View to render, to be resolved

* by the DispatcherServlet's ViewResolver

* @see #addObject

public ModelAndView(String viewName) {

this.view = viewName;

}

/**

* Convenient constructor when there is no model data to expose.

* Can also be used in conjunction with <code>addObject</code>.

* @param view View object to render

* @see #addObject

public ModelAndView(View view) {

this.view = view;

}

/**

* Creates new ModelAndView given a view name and a model.

* @param viewName name of the View to render, to be resolved

* by the DispatcherServlet's ViewResolver

* @param model Map of model names (Strings) to model objects

* (Objects). Model entries may not be <code>null</code>, but the

* model Map may be <code>null</code> if there is no model data.

public ModelAndView(String viewName, Map<String, ?> model) {

this.view = viewName;

if (model != null) {

getModelMap().addAllAttributes(model);

}

/**

* Creates new ModelAndView given a View object and a model.

* <emphasis>Note: the supplied model data is copied into the internal

* storage of this class. You should not consider to modify the supplied

* Map after supplying it to this class</emphasis>

* @param view View object to render

* @param model Map of model names (Strings) to model objects

* (Objects). Model entries may not be <code>null</code>, but the

* model Map may be <code>null</code> if there is no model data.

public ModelAndView(View view, Map<String, ?> model) {

this.view = view;

if (model != null) {

getModelMap().addAllAttributes(model);

}

/**

* Convenient constructor to take a single model object.

* @param viewName name of the View to render, to be resolved

* by the DispatcherServlet's ViewResolver

* @param modelName name of the single entry in the model

* @param modelObject the single model object

public ModelAndView(String viewName, String modelName, Object modelObject) {

this.view = viewName;

addObject(modelName, modelObject);

}

/**

* Convenient constructor to take a single model object.

* @param view View object to render

* @param modelName name of the single entry in the model

* @param modelObject the single model object

public ModelAndView(View view, String modelName, Object modelObject) {

this.view = view;

addObject(modelName, modelObject);

}

/**

* Set a view name for this ModelAndView, to be resolved by the

* DispatcherServlet via a ViewResolver. Will override any

* pre-existing view name or View.

public void setViewName(String viewName) {

this.view = viewName;

}

/**

* Return the view name to be resolved by the DispatcherServlet

* via a ViewResolver, or <code>null</code> if we are using a View object.

public String getViewName() {

return (this.view instanceof String ? (String) this.view : null);

}

/**

* Set a View object for this ModelAndView. Will override any

* pre-existing view name or View.

public void setView(View view) {

this.view = view;

}

/**

* Return the View object, or <code>null</code> if we are using a view name

* to be resolved by the DispatcherServlet via a ViewResolver.

public View getView() {

return (this.view instanceof View ? (View) this.view : null);

}

/**

* Indicate whether or not this <code>ModelAndView</code> has a view, either

* as a view name or as a direct {@link View} instance.

public boolean hasView() {

return (this.view != null);

}

/**

* Return whether we use a view reference, i.e. <code>true</code>

* if the view has been specified via a name to be resolved by the

* DispatcherServlet via a ViewResolver.

public boolean isReference() {

return (this.view instanceof String);

}

/**

* Return the model map. May return <code>null</code>.

* Called by DispatcherServlet for evaluation of the model.

protected Map<String, Object> getModelInternal() {

return this.model;

}

/**

* Return the underlying <code>ModelMap</code> instance (never <code>null</code>).

public ModelMap getModelMap() {

if (this.model == null) {

this.model = new ModelMap();

}

return this.model;

}

/**

* Return the model map. Never returns <code>null</code>.

* To be called by application code for modifying the model.

public Map<String, Object> getModel() {

return getModelMap();

}

/**

* Add an attribute to the model.

* @param attributeName name of the object to add to the model

* @param attributeValue object to add to the model (never <code>null</code>)

* @see ModelMap#addAttribute(String, Object)

* @see #getModelMap()

public ModelAndView addObject(String attributeName, Object attributeValue) {

getModelMap().addAttribute(attributeName, attributeValue);

return this;

}

/**

* Add an attribute to the model using parameter name generation.

* @param attributeValue the object to add to the model (never <code>null</code>)

* @see ModelMap#addAttribute(Object)

* @see #getModelMap()

public ModelAndView addObject(Object attributeValue) {

getModelMap().addAttribute(attributeValue);

return this;

}

/**

* Add all attributes contained in the provided Map to the model.

* @param modelMap a Map of attributeName -> attributeValue pairs

* @see ModelMap#addAllAttributes(Map)

* @see #getModelMap()

public ModelAndView addAllObjects(Map<String, ?> modelMap) {

getModelMap().addAllAttributes(modelMap);

return this;

}

/**

* Clear the state of this ModelAndView object.

* The object will be empty afterwards.

* <p>Can be used to suppress rendering of a given ModelAndView object

* in the <code>postHandle</code> method of a HandlerInterceptor.

* @see #isEmpty()

* @see HandlerInterceptor#postHandle

public void clear() {

this.view = null;

this.model = null;

this.cleared = true;

}

/**

* Return whether this ModelAndView object is empty,

* i.e. whether it does not hold any view and does not contain a model.

public boolean isEmpty() {

return (this.view == null && CollectionUtils.isEmpty(this.model));

}

/**

* Return whether this ModelAndView object is empty as a result of a call to {@link #clear}

* i.e. whether it does not hold any view and does not contain a model.

* <p>Returns <code>false</code> if any additional state was added to the instance

* <strong>after</strong> the call to {@link #clear}.

* @see #clear()

public boolean wasCleared() {

return (this.cleared && isEmpty());

}

/**

* Return diagnostic information about this model and view.

@Override

public String toString() {

StringBuilder sb = new StringBuilder("ModelAndView: ");

if (isReference()) {

sb.append("reference to view with name '").append(this.view).append("'");

}

else {

sb.append("materialized View is [").append(this.view).append(']');

}

sb.append("; model is ").append(this.model);

return sb.toString();

}

測試代碼如下：

package com.sxt.web;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.mvc.multiaction.MultiActionController;

import com.sxt.po.User;

@Controller

@RequestMapping("/user.do")

public class UserController extends MultiActionController {

@RequestMapping(params="method=reg")

public ModelAndView reg(String uname){

ModelAndView mv = new ModelAndView();

mv.setViewName("index");

//mv.setView(new RedirectView("index"));

User u = new User();

u.setUname("高淇");

mv.addObject(u); //查看源代碼，得知，直接放入對象。屬性名為”首字母小寫的類名”。一般建議手動增加屬性名稱。

mv.addObject("a", "aaaa");

return mv;

}

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

</head>

<body>

<h1>${requestScope.a}</h1>

<h1>${requestScope.user.uname}</h1>

</body>

</html>

地址欄輸入：http://localhost:8080/springmvc03/user.do?method=reg

結果為：

基于spring 3.0mvc 框架的文件上傳實現

1. spring使用了apache-commons下得上傳組件，因此，我們需要引入兩個jar包：

1. apache-commons-fileupload.jar

2. apache-commons-io.jar

2. 在springmvc-servlet.xml配置文件中，增加CommonsMultipartResoler配置：

<bean id="multipartResolver"

class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >

</bean>

3. 建立upload.jsp頁面，內容如下：

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>測試springmvc中上傳的實現</title>

</head>

<body>

</form>

</body>

</html>

4. 建立控制器，代碼如下：

package com.sxt.web;

import java.io.File;

import java.util.Date;

import javax.servlet.ServletContext;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.context.ServletContextAware;

import org.springframework.web.multipart.commons.CommonsMultipartFile;

@Controller

public class FileUploadController implements ServletContextAware {

private ServletContext servletContext;

@Override

public void setServletContext(ServletContext context) {

this.servletContext = context;

}

@RequestMapping(value="/upload.do", method = RequestMethod.POST)

public String handleUploadData(String name,@RequestParam("file")CommonsMultipartFile file){

if (!file.isEmpty()) {

String path = this.servletContext.getRealPath("/tmp/"); //獲取本地存儲路徑

System.out.println(path);

String fileName = file.getOriginalFilename();

String fileType = fileName.substring(fileName.lastIndexOf("."));

System.out.println(fileType);

File file2 = new File(path,new Date().getTime() + fileType); //新建一個文件

try {

file.getFileItem().write(file2); //將上傳的文件寫入新建的文件中

} catch (Exception e) {

e.printStackTrace();

}

return "redirect:upload_ok.jsp";

}else{

return "redirect:upload_error.jsp";

}

5. 建立upload_ok.jsp頁面

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

</head>

<body>

</body>

</html>

6. 建立upload_error.jsp頁面

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

</head>

<body>

</body>

</html>

7. 發布項目，運行測試：http://localhost:8080/springmvc03/upload.jsp

進入項目發布后的目錄，發現文件上傳成功：

處理ajax請求

spring使用了jackson類庫，幫助我們在java對象和json、xml數據之間的互相轉換。他可以將控制器返回的對象直接轉換成json數據，供客戶端使用。客戶端也可以傳送json數據到服務器進行直接轉換。使用步驟如下：

1. 項目中需要引入如下兩個jar包：

jackson-core-asl-1.7.2jar

jackson-mapper-asl-1.7.2jar

2. spring配置文件中修改：

<mvc:annotation-driven />

<list>

</list>

</property>

</bean>

3. 客戶端代碼a.jsp如下：

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>My JSP 'index.jsp' starting page</title>

function createAjaxObj(){

var req;

if(window.XMLHttpRequest){

req = new XMLHttpRequest();

}else{

req = new ActiveXObject("Msxml2.XMLHTTP"); //ie

}

return req;

}

function sendAjaxReq(){

var req = createAjaxObj();

req.open("get","myajax.do?method=test2&uname=張三");

req.setRequestHeader("accept","application/json");

req.onreadystatechange = function(){

eval("var result="+req.responseText);

document.getElementById("div1").innerHTML=result[0].uname;

}

req.send(null);

}

</script>

</head>

<body>

</body>

</html>

4. 服務器端代碼如下：

package com.sxt.web;

import java.io.UnsupportedEncodingException;

import java.util.ArrayList;

import java.util.List;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestBody;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.ResponseBody;

import com.sxt.po.User;

@Controller

@RequestMapping("myajax.do")

public class MyAjaxController {

@RequestMapping(params="method=test1",method=RequestMethod.GET)

public @ResponseBody List<User> test1(String uname) throws Exception{

String uname2 = new String(uname.getBytes("iso8859-1"),"gbk");

System.out.println(uname2);

System.out.println("MyAjaxController.test1()");

List<User> list = new ArrayList<User>();

list.add(new User("高淇","123"));

list.add(new User("馬士兵","456"));

return list;

}

5. 測試。

a) 啟動服務器。輸入：http://localhost:8080/springmvc03/a.jsp

Spring中的攔截器

定義spring攔截器兩種基本方式

1. 實現接口：org.springframework.web.servlet.HandlerInterceptor。

接口中有如下方法需要重寫：

注意：參數中的Object handler是下一個攔截器。

a) public boolean preHandle
(HttpServletRequest request,HttpServletResponse response,
Object handler) throws Exception

該方法在action執行前執行，可以實現對數據的預處理，比如：編碼、安全控制等。

如果方法返回true，則繼續執行action。

b) public void postHandle
(HttpServletRequest request,HttpServletResponse response,
Object handler, ModelAndView modelAndView) throws Exception

該方法在action執行后，生成視圖前執行。在這里，我們有機會修改視圖層數據。

c) public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)throws Exception

最后執行，通常用于釋放資源，處理異常。我們可以根據ex是否為空，來進行相關的異常處理。因為我們在平時處理異常時，都是從底層向上拋出異常，最后到了spring框架從而到了這個方法中。

2. 繼承適配器：
org.springframework.web.servlet.handler.HandlerInterceptorAdapter

這個適配器實現了HandlerInterceptor接口。提供了這個接口中所有方法的空實現。

如下我們寫出兩個攔截器的示例代碼，僅供大家參考：

package com.sxt.interceptor;

import javax.interceptor.Interceptors;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

public class MyInterceptor implements HandlerInterceptor {

@Override

public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)throws Exception {

System.out.println("最后執行！！！一般用于釋放資源！！");

}

@Override

public void postHandle(HttpServletRequest request,HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

System.out.println("Action執行之后，生成視圖之前執行！！");

}

@Override

public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {

System.out.println("action之前執行！！！");

return true; //繼續執行action

}

package com.sxt.interceptor;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class MyInterceptor2 extends HandlerInterceptorAdapter {

@Override

public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {

System.out.println("MyInterceptor2.preHandle()");

return true; //繼續執行action

}

3. XML中如何配置。如下為示例代碼：

<mvc:interceptors>

<mvc:interceptor>

<mvc:mapping path="/user.do" />

</mvc:interceptor>

</mvc:interceptors>

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SpringMVC Spring MVC Web框架

SpringMVC 清晰簡單教程

Spring MVC 背景介紹

常見MVC框架比較

基于spring2.5的采用XML配置的spring MVC項目

基于spring2.5注解實現的spring MVC項目

基于spring 3.0項目開發實例

Spring MVC 3.0 深入

核心原理

spring3.0中相關jar包的含義

@Controller控制器定義

@RequestMapping

@RequestParam

@SessionAttributes

@ModelAttribute

Controller類中方法參數的處理

Controller類中方法返回值的處理

請求轉發和重定向

獲得request對象、session對象

ModelMap

ModelAndView模型視圖類

基于spring 3.0mvc 框架的文件上傳實現

處理ajax請求

Spring中的攔截器

定義spring攔截器兩種基本方式

相關經驗

相關資訊

相關文檔

目錄