---------- 轉自尚學堂高淇 ---------

Spring MVC 背景介紹

Spring 框架提供了構建 Web 應用程式的全功能 MVC 模組。使用 Spring 可插入的 MVC 架構，可以選擇是使用內建的 Spring Web 框架還是 Struts 這樣的 Web 框架。通過策略介面，Spring 框架是高度可配置的，而且包含多種檢視技術，例如 JavaServer Pages（JSP）技術、Velocity、Tiles、iText 和 POI。Spring MVC 框架並不知道使用的檢視，所以不會強迫您只使用 JSP 技術。Spring MVC 分離了控制器、模型物件、分派器以及處理程式物件的角色，這種分離讓它們更容易進行定製。

常見MVC框架比較

執行效能上：

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的效能低的原因是因為OGNL和值棧造成的。所以，如果你的系統併發量高，可以使用freemaker進行顯示，而不是採用OGNL和值棧。這樣，在效能上會有相當大得提高。

基於spring2.5的採用XML配置的spring MVC專案

注：本專案全部基於XML配置。同時，整合了hibernate。採用的是：spring MVC+hibernate+spring的開發架構。

建立web專案
匯入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包為hibernate相關jar包)

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>

增加web-config.xml(這裡包含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>

在WEB-INF下增加service-config.xml(這裡包含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>

在WEB-INF下增加hib-config.xml(這裡包含spring整合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執行。

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

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

在WEB-INF下增加dao-config.xml(這裡包含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>

建立相關類和包結構，如下圖所示：

各類程式碼如下：

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;

}

執行測試：

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

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

基於spring2.5註解實現的spring MVC專案

我們採用sprng MVC開發專案時，通常都會採用註解的方式，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。這個專案完全採用註解的方式開發。同時，我們以後的spring MVC專案也都會採用註解的方式。

建立web專案
匯入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包為hibernate相關jar包)

修改web.xml，檔案內容如下：

<?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>

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>

hib-config.xml(配置了spring整合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執行。

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

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

WEB-INF下建立jsp資料夾，並且將index.jsp放入該資料夾下。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>

建立整個專案的包結構和相關類。如下圖所示：

User、UserDao、UserService、UserController類的程式碼如下：

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;

}

執行測試：

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

則會呼叫userController的reg方法，從而將資料內容插入到資料庫中。

基於spring 3.0專案開發例項

spring3.0完全相容spring2.5.因此，我們只要簡單修改上面專案的類庫和配置檔案。類的程式碼保持不變。

匯入相關jar包，如下：

spring配置檔案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>

spring配置檔案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執行。

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

<tx:method name="*"/>

</tx:attributes>

</tx:advice>

</beans>

web.xml檔案不變
類的程式碼不變。
執行，測試。跟上一個專案保持一致。

Spring MVC 3.0 深入

核心原理

使用者傳送請求給伺服器。url：user.do
伺服器收到請求。發現DispatchServlet可以處理。於是呼叫DispatchServlet。
DispatchServlet內部，通過HandleMapping檢查這個url有沒有對應的Controller。如果有，則呼叫Controller。
Controller開始執行。
Controller執行完畢後，如果返回字串，則ViewResolver將字串轉化成相應的檢視物件；如果返回ModelAndView物件，該物件本身就包含了檢視物件資訊。
DispatchServlet將執檢視物件中的資料，輸出給伺服器。
伺服器將資料輸出給客戶端。

spring3.0中相關jar包的含義

org.springframework.aop-3.0.3.RELEASE.jar	spring的aop面向切面程式設計
org.springframework.asm-3.0.3.RELEASE.jar	spring獨立的asm位元組碼生成程式
org.springframework.beans-3.0.3.RELEASE.jar	IOC的基礎實現
org.springframework.context-3.0.3.RELEASE.jar	IOC基礎上的擴充套件服務
org.springframework.core-3.0.3.RELEASE.jar	spring的核心包
org.springframework.expression-3.0.3.RELEASE.jar	spring的表示式語言
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執行緒共享。因此，我們將控制器設計成無狀態類。

在spring 3.0中，通過@controller標註即可將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配置檔案中增加如下定義：

<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和類繫結。

在方法前面定義，則將url和類的方法繫結，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

一般用於將指定的請求引數付給方法中形參。示例程式碼如下：

@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引數的值付給uname。當然，如果請求引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。示例程式碼如下：

@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資料。

return "index";

}

<body>

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

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

</body>

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

@ModelAttribute

這個註解可以跟@SessionAttributes配合在一起用。可以將ModelMap中屬性的值通過該註解自動賦給指定變數。

示例程式碼如下：

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[微軟使用者1] ,ModelMap map) {

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

System.out.println(uname);

return "index";

}

先呼叫reg4方法，再呼叫reg5方法。我們發現控制檯列印出來：尚學堂高淇

Controller類中方法引數的處理

Controller類中方法返回值的處理

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字首+返回值+suffix字尾組成

b) 程式碼如下：

@RequestMapping(params="method=reg4")

public String reg4(ModelMap map) {

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

return "index";

}

字首為：/WEB-INF/jsp/ 字尾是：.jsp

在轉發到：/WEB-INF/jsp/index.jsp

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

請求轉發和重定向

程式碼示例：

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物件、session物件

普通的Controller類，示例程式碼如下：

@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中放入資料，然後在forward的頁面上顯示這些資料。通過el表示式、JSTL、java程式碼均可。程式碼如下：

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模型檢視類

見名知意，從名字上我們可以知道ModelAndView中的Model代表模型，View代表檢視。即，這個類把要顯示的資料儲存到了Model屬性中，要跳轉的檢視資訊儲存到了view屬性。我們看一下ModelAndView的部分原始碼，即可知其中關係：

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();

}

測試程式碼如下：

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); //檢視原始碼，得知，直接放入物件。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>

位址列輸入：http://localhost:8080/springmvc03/user.do?method=reg

結果為：

基於spring 3.0mvc 框架的檔案上傳實現

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

apache-commons-fileupload.jar
apache-commons-io.jar

2. 在springmvc-servlet.xml配置檔案中，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，程式碼如下：

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")[微軟使用者2] CommonsMultipartFile file){

if (!file.isEmpty()) {

String path = this.servletContext.getRealPath("/tmp/"); //獲取本地儲存路徑

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); //新建一個檔案

try {

file.getFileItem().write(file2); //將上傳的檔案寫入新建的檔案中

} 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>

釋出專案，執行測試：http://localhost:8080/springmvc03/upload.jsp

進入專案釋出後的目錄，發現檔案上傳成功：

處理ajax請求

spring使用了jackson類庫，幫助我們在java物件和json、xml資料之間的互相轉換。他可以將控制器返回的物件直接轉換成json資料，供客戶端使用。客戶端也可以傳送json資料到伺服器進行直接轉換。使用步驟如下：

1. 專案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配置檔案中修改：

<mvc:annotation-driven />

<list>

</list>

</property>

</bean>

客戶端程式碼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>

伺服器端程式碼如下：

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;

}

測試。

a) 啟動伺服器。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

實現介面：org.springframework.web.servlet.HandlerInterceptor。

介面中有如下方法需要重寫：

注意：引數中的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，可以實現對資料的預處理，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執行後，生成檢視前執行。在這裡，我們有機會修改檢視層資料。

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

最後執行，通常用於釋放資源，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，都是從底層向上丟擲異常，最後到了spring框架從而到了這個方法中。

繼承介面卡：
org.springframework.web.servlet.handler.HandlerInterceptorAdapter

這個介面卡實現了HandlerInterceptor介面。提供了這個介面中所有方法的空實現。

如下我們寫出兩個攔截器的示例程式碼，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("最後執行！！！一般用於釋放資源！！");

}

@Override

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

System.out.println("Action執行之後，生成檢視之前執行！！");

}

@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

}

XML中如何配置。如下為示例程式碼：

<mvc:interceptors>

<mvc:interceptor>

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

</mvc:interceptor>

</mvc:interceptors>

轉載於:https://www.cnblogs.com/xifenglou/p/5606847.html

spring mvc 快速入門

---------- 轉自尚學堂高淇 ---------

Spring MVC 背景介紹

常見MVC框架比較

基於spring2.5的採用XML配置的spring MVC專案

基於spring2.5註解實現的spring MVC專案

基於spring 3.0專案開發例項

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類中方法引數的處理

Controller類中方法返回值的處理

請求轉發和重定向

獲得request物件、session物件

ModelMap

ModelAndView模型檢視類

基於spring 3.0mvc 框架的檔案上傳實現

處理ajax請求

Spring中的攔截器

定義spring攔截器兩種基本方式

相關文章

spring mvc 快速入門

---------- 轉自尚學堂 高淇 ---------

Spring MVC 背景介紹

常見MVC框架比較

基於spring2.5的採用XML配置的spring MVC專案

基於spring2.5註解實現的spring MVC專案

基於spring 3.0專案開發例項

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類中方法引數的處理

Controller類中方法返回值的處理

請求轉發和重定向

獲得request物件、session物件

ModelMap

ModelAndView模型檢視類

基於spring 3.0mvc 框架的檔案上傳實現

處理ajax請求

Spring中的攔截器

定義spring攔截器兩種基本方式

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