SpringMVC总结

Spring  MVC 背景介绍

Spring框架提供了构建 Web 应用程序的全功能 MVC 模块。使用 Spring 可插入的 MVC 架构,可以选择是使用内置的 Spring Web 框架还是 Struts 这样的 Web 框架。通过策略接口,Spring 框架是高度可配置的,而且包含多种视图技术,例如 JavaServer Pages(JSP)技术、Velocity、Tiles、iText 和 POI。Spring MVC 框架并不知道使用的视图,所以不会强迫您只使用 JSP 技术。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定制。

 

 

常见MVC框架比较

运行性能上:

         Jsp+servlet>struts1>springmvc>struts2+freemarker>>struts2,ognl,值栈。

开发效率上,基本正好相反。值得强调的是,spring mvc开发效率和struts2不相上下。

 

Struts2的性能低的原因是因为OGNL和值栈造成的。所以,如果你的系统并发量高,可以使用freemaker进行显示,而不是采用OGNL和值栈。这样,在性能上会有相当大得提高。

 

 

基于spring2.5的采用XML配置的spring MVC项目

注:本项目全部基于XML配置。同时,集成了hibernate。采用的是:springMVC+hibernate+spring的开发架构。

1.      建立web项目

2.      导入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包为hibernate相关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>

        <servlet-name>dispatcherServletservlet-name>

        <servlet-class>

            org.springframework.web.servlet.DispatcherServlet

        servlet-class>

        <init-param>

            <param-name>contextConfigLocationparam-name>

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

        init-param>

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

    servlet>

    <servlet-mapping>

        <servlet-name>dispatcherServletservlet-name>

        <url-pattern>*.dourl-pattern>

    servlet-mapping>

web-app>

 

4.      增加web-config.xml(这里包含spring mvc相关的相关配置)

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">

        <property name="paramName" value="action"/>

        <property name="defaultMethodName" value="list"/>

    bean>

 

  

    <bean id="viewResolver"

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

        <property name="viewClass"

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

       

        <property name="suffix" value=".jsp"/>

    bean>

 

    <bean id="urlMapping"

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

        <property name="mappings">

            <props>

                <prop key="user.do">userControllerprop>

            props>

        property>

    bean>

 

<bean id="userController" class="com.sxt.action.UserController">

    <property name="userService" ref="userService">property>

bean>

beans>

 

5.      在WEB-INF下增加service-config.xml(这里包含service层类的相关配置)

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="userService" class="com.sxt.service.UserService">

       <property name="userDao" ref="userDao">property>

    bean>

   

beans>

 

6.      在WEB-INF下增加hib-config.xml(这里包含spring集成hibernate相关的配置)

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> 

            <property name="url" value="jdbc:mysql://localhost:3306/myhib">property> 

            <property name="username" value="root">property> 

            <property name="password" value="123456">property>

    bean> 

 

   <bean id="sessionFactory" 

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

           <property name="dataSource"> 

               <ref bean="dataSource" /> 

           property>

           <property name="hibernateProperties"> 

               <props> 

                 

                   <prop key="hibernate.dialect"> 

                       org.hibernate.dialect.MySQLDialect 

                   prop> 

                   <prop key="hibernate.show_sql">trueprop>

                   <prop key="hibernate.hbm2ddl.auto">updateprop>

               props>

           property>

       <property name="packagesToScan">

           <value>com.sxt.povalue>

       property>

   bean> 

 

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate" >

    <property name="sessionFactory" ref="sessionFactory">property>

bean>

 

 

<bean id="jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate">  

     <property name="dataSource" ref="dataSource"/>  

bean> 

 

 

<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager" >

    <property name="sessionFactory" ref="sessionFactory">property>

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"  />

      

       <tx:method name="*"/>   

    tx:attributes>

tx:advice>

 

beans>

 

7.      在WEB-INF下增加dao-config.xml(这里包含dao层类的相关配置)

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="userDao" class="com.sxt.dao.UserDao">

      <property name="hibernateTemplate" ref="hibernateTemplate">property>

    bean>

beans>

 

8.      建立相关类和包结构,如下图所示:

9.      各类代码如下:

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.  运行测试:

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

 

结果:数据库中增加zhangsan的记录。页面跳转到index.jsp上,显示:

基于spring2.5注解实现的spring MVC项目

我们采用sprng MVC开发项目时,通常都会采用注解的方式,这样可以大大提高我们的开发效率。实现零配置。下面我们从零开始重新做一个spring MVC的配置。这个项目完全采用注解的方式开发。同时,我们以后的spring MVC项目也都会采用注解的方式。

 

1.      建立web项目

2.      导入jar包(spring.jar, spring-webmvc.jar, commons-logging.jar。其他jar包为hibernate相关jar包)

 

 

3.      修改web.xml,文件内容如下:

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>

        <servlet-name>springmvcservlet-name>

        <servlet-class>

            org.springframework.web.servlet.DispatcherServlet

        servlet-class>

        <init-param>

            <param-name>contextConfigLocationparam-name>

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

        init-param>

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

    servlet>

 

    <servlet-mapping>

        <servlet-name>springmvcservlet-name>

        <url-pattern>*.dourl-pattern>

    servlet-mapping>

 

web-app>

 

 

4.      springmvc-servlet.xml配置内容如下:

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.mvc.annotation.AnnotationMethodHandlerAdapter"/>

 

   

    <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> 

            <property name="url" value="jdbc:mysql://localhost:3306/myhib">property> 

            <property name="username" value="root">property> 

            <property name="password" value="123456">property>

    bean> 

 

   <bean id="sessionFactory" 

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

           <property name="dataSource"> 

               <ref bean="dataSource" /> 

           property>

           <property name="hibernateProperties"> 

               <props> 

                 

                   <prop key="hibernate.dialect"> 

                       org.hibernate.dialect.MySQLDialect 

                   prop> 

                   <prop key="hibernate.show_sql">trueprop>

                   <prop key="hibernate.hbm2ddl.auto">updateprop>

               props>

           property>

       <property name="packagesToScan">

           <value>com.sxt.povalue>

       property>

   bean> 

 

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate" >

    <property name="sessionFactory" ref="sessionFactory">property>

bean>

 

 

<bean id="jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate">  

     <property name="dataSource" ref="dataSource"/>  

bean> 

 

 

<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager" >

    <property name="sessionFactory" ref="sessionFactory">property>

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"  />

      

       <tx:method name="*"/>   

    tx:attributes>

tx:advice>

 

beans>

 

6.      WEB-INF下建立jsp文件夹,并且将index.jsp放入该文件夹下。Index.jsp的内容如下:

<%@ 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>

    <base href="<%=basePath%>">

   

    <title>My JSP 'index.jsp' starting pagetitle>

    <meta http-equiv="pragma" content="no-cache">

    <meta http-equiv="cache-control" content="no-cache">

    <meta http-equiv="expires" content="0">   

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

    <meta http-equiv="description" content="This is my page">

   

  head>

 

  <body>

   <h1>**********${params.uname}h1>

   <h1>**********${requestScope.u}h1>

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

  body>

html>

 

 

7.      建立整个项目的包结构和相关类。如下图所示:

8.      User、UserDao、UserService、UserController类的代码如下:

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.      运行测试:

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

 

则会调用userController的reg方法,从而将数据内容插入到数据库中。

 

 

 

 

 

 

 

基于spring 3.0项目开发实例

spring3.0完全兼容spring2.5.因此,我们只要简单修改上面项目的类库和配置文件。类的代码保持不变。

 

1.      导入相关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.mvc.annotation.AnnotationMethodHandlerAdapter"/>

 

   

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

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

        

    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />   

    bean>

beans>

 

3.      spring配置文件hib-config.xml内容修改如下:

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> 

            <property name="url" value="jdbc:mysql://localhost:3306/myhib">property> 

            <property name="username" value="root">property> 

            <property name="password" value="123456">property>

    bean> 

 

   <bean id="sessionFactory" 

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

           <property name="dataSource"> 

               <ref bean="dataSource" /> 

           property>

           <property name="hibernateProperties"> 

               <props> 

                 

                   <prop key="hibernate.dialect"> 

                       org.hibernate.dialect.MySQLDialect 

                   prop> 

                   <prop key="hibernate.show_sql">trueprop>

                   <prop key="hibernate.hbm2ddl.auto">updateprop>

               props>

           property>

       <property name="packagesToScan">

           <value>com.sxt.povalue>

       property>

   bean> 

 

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate" >

    <property name="sessionFactory" ref="sessionFactory">property>

bean>

 

 

<bean id="jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate">  

     <property name="dataSource" ref="dataSource"/>  

bean> 

 

 

<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager" >

    <property name="sessionFactory" ref="sessionFactory">property>

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"  />

      

       <tx:method name="*"/>   

    tx:attributes>

tx:advice>

 

beans>

 

4.      web.xml文件不变

5.      类的代码不变。

6.      运行,测试。跟上一个项目保持一致。

 

 

Spring MVC 3.0 深入

核心原理

1.      用户发送请求给服务器。url:user.do

2.      服务器收到请求。发现DispatchServlet可以处理。于是调用DispatchServlet。

3.      DispatchServlet内部,通过HandleMapping检查这个url有没有对应的Controller。如果有,则调用Controller。

4.      Controller开始执行。

5.      Controller执行完毕后,如果返回字符串,则ViewResolver将字符串转化成相应的视图对象;如果返回ModelAndView对象,该对象本身就包含了视图对象信息。

6.      DispatchServlet将执视图对象中的数据,输出给服务器。

7.      服务器将数据输出给客户端。

spring3.0中相关jar包的含义

org.springframework.aop-3.0.3.RELEASE.jar

spring的aop面向切面编程

org.springframework.asm-3.0.3.RELEASE.jar

spring独立的asm字节码生成程序

org.springframework.beans-3.0.3.RELEASE.jar

IOC的基础实现

org.springframework.context-3.0.3.RELEASE.jar

IOC基础上的扩展服务

org.springframework.core-3.0.3.RELEASE.jar

spring的核心包

org.springframework.expression-3.0.3.RELEASE.jar

spring的表达式语言

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控制器定义

和Struts1一样,Spring的Controller是Singleton的。这就意味着会被多个请求线程共享。因此,我们将控制器设计成无状态类。

 

在spring 3.0中,通过@controller标注即可将class定义为一个controller类。为使spring能找到定义为controller的bean,需要在spring-context配置文件中增加如下定义:

 

base-package="com.sxt.web"/>

 

         注:实际上,使用@component,也可以起到@Controller同样的作用。

 

@RequestMapping

 

    在类前面定义,则将url和类绑定。

       在方法前面定义,则将url和类的方法绑定,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

         一般用于将指定的请求参数付给方法中形参。示例代码如下:

        

@RequestMapping(params="method=reg5")

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

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

       System.out.println(uname);

       return "index";

    }

        

         这样,就会将name参数的值付给uname。当然,如果请求参数名称和形参名称保持一致,则不需要这种写法。

@SessionAttributes

    将ModelMap中指定的属性放到session中。示例代码如下:

   

@Controller

@RequestMapping("/user.do")

@SessionAttributes({"u","a"})   //ModelMap中属性名字为ua的再放入session中。这样,requestsession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");  //u放入request作用域中,这样转发页面也可以取到这个数据。

       return "index";

    }

}

  <body>

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

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

  body>

   

    注:名字为”user”的属性再结合使用注解@SessionAttributes可能会报错。

 

@ModelAttribute

      这个注解可以跟@SessionAttributes配合在一起用。可以将ModelMap中属性的值通过该注解自动赋给指定变量。

    示例代码如下:

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","尚学堂高淇");

       return "index";

    }

   

    @RequestMapping(params="method=reg5")

public String reg5(@ModelAttribute("u")String uname[1] ,ModelMap map) {

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

       System.out.println(uname);

       return "index";

    }

   

}

 

先调用reg4方法,再调用reg5方法。我们发现控制台打印出来:尚学堂高淇

 

Controller类中方法参数的处理

 

Controller类中方法返回值的处理

1.      返回string(建议)

a)        根据返回值找对应的显示页面。路径规则为:prefix前缀+返回值+suffix后缀组成

b)        代码如下:

@RequestMapping(params="method=reg4")

    public String reg4(ModelMap map) {

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

       return "index";

    }

前缀为:/WEB-INF/jsp/    后缀是:.jsp

在转发到:/WEB-INF/jsp/index.jsp

 

2.      也可以返回ModelMap、ModelAndView、map、List、Set、Object、无返回值。 一般建议返回字符串!

 

 

请求转发和重定向

         代码示例:

        

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"; //转发

//     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";

    }

   

}

        

         访问reg4方法,既可以看到效果。

 

 

 

获得request对象、session对象

普通的Controller类,示例代码如下:

@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的实现,可以在其中存放属性,作用域同request。下面这个示例,我们可以在modelMap中放入数据,然后在forward的页面上显示这些数据。通过el表达式、JSTL、java代码均可。代码如下:

        

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>

  <head>head>

  <body>

       <h1>${requestScope.a}h1>

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

  body>

html>

 

ModelAndView模型视图类

见名知意,从名字上我们可以知道ModelAndView中的Model代表模型,View代表视图。即,这个类把要显示的数据存储到了Model属性中,要跳转的视图信息存储到了view属性。我们看一下ModelAndView的部分源码,即可知其中关系:

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 addObject.

     * @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 addObject.

     * @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 null, but the

     * model Map may be null if there is no model data.

     */

    public ModelAndView(String viewName, Map model) {

       this.view = viewName;

       if (model != null) {

           getModelMap().addAllAttributes(model);

       }

    }

 

    /**

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

     * 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

     * @param view View object to render

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

     * (Objects). Model entries may not be null, but the

     * model Map may be null if there is no model data.

     */

    public ModelAndView(View view, Map 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 null 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 null 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 ModelAndView 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. true

     * 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 null.

     * Called by DispatcherServlet for evaluation of the model.

     */

    protected Map getModelInternal() {

       return this.model;

    }

 

    /**

     * Return the underlying ModelMap instance (never null).

     */

    public ModelMap getModelMap() {

       if (this.model == null) {

           this.model = new ModelMap();

       }

       return this.model;

    }

 

    /**

     * Return the model map. Never returns null.

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

     */

    public Map 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 null)

     * @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 null)

     * @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 modelMap) {

       getModelMap().addAllAttributes(modelMap);

       return this;

    }

 

 

    /**

     * Clear the state of this ModelAndView object.

     * The object will be empty afterwards.

     *

Can be used to suppress rendering of a given ModelAndView object

     * in the postHandle 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.

     *

Returns false if any additional state was added to the instance

     * after 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();

    }

}

 

测试代码如下:

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);   //查看源代码,得知,直接放入对象。属性名为”首字母小写的类名”。 一般建议手动增加属性名称。

       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>

地址栏输入:http://localhost:8080/springmvc03/user.do?method=reg

结果为:

 

 

基于spring 3.0mvc 框架的文件上传实现

1. spring使用了apache-commons下得上传组件,因此,我们需要引入两个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" > 

    <property name="defaultEncoding" value="gbk"/>  

    <property name="maxInMemorySize" value="10240"/>  

    <property name="uploadTempDir" value="/upload/"/>  

    <property name="maxUploadSize" value="-1"/>  

bean>

 

3.  建立upload.jsp页面,内容如下:

        

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

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

<html>

    <head>

       <title>测试springmvc中上传的实现title>

    head>

    <body>

<form action="upload.do"  method="post" enctype="multipart/form-data">

           <input type="text" name="name" />

           <input type="file" name="file" />

           <input type="submit" />

       form>

    body>

html>

 

4. 建立控制器,代码如下:

        

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")[2] CommonsMultipartFile file){

                   if (!file.isEmpty()) {

                               String path = this.servletContext.getRealPath("/tmp/");  //获取本地存储路径

                               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); //新建一个文件

                               try {

                                         file.getFileItem().write(file2); //将上传的文件写入新建的文件中

                               } catch (Exception e) {

                                         e.printStackTrace();

                               }

                               return "redirect:upload_ok.jsp";

                            }else{

                                     return "redirect:upload_error.jsp";

                            }

         }

}

 

5. 建立upload_ok.jsp页面

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

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

<html>

  <head>

  head>

  <body>

       <h1>上传成功!h1>

  body>

html>

 

6. 建立upload_error.jsp页面

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

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

<html>

  <head>

  head>

  <body>

       <h1>上传失败!h1>

  body>

html>

 

7.      发布项目,运行测试:http://localhost:8080/springmvc03/upload.jsp

   进入项目发布后的目录,发现文件上传成功:

 

处理ajax请求

spring使用了jackson类库,帮助我们在java对象和json、xml数据之间的互相转换。他可以将控制器返回的对象直接转换成json数据,供客户端使用。客户端也可以传送json数据到服务器进行直接转换。使用步骤如下:

 

1.  项目中需要引入如下两个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 /> 

   

      <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> 

        <property name="cacheSeconds" value="0" /> 

        <property name="messageConverters"> 

            <list> 

                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">bean> 

            list> 

        property>

    bean>  

 

3.      客户端代码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>

    <base href="<%=basePath%>">

   

    <title>My JSP 'index.jsp' starting pagetitle>

    <meta http-equiv="pragma" content="no-cache">

    <meta http-equiv="cache-control" content="no-cache">

    <meta http-equiv="expires" content="0">   

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

    <meta http-equiv="description" content="This is my page">

    <script>

       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=张三");

           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>

    <a href="javascript:void(0);" onclick="sendAjaxReq();">测试a>

    <div id="div1">div>

  body>

html>

 

 

4.      服务器端代码如下:

        

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 test1(String uname) throws Exception{

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

                   System.out.println(uname2);

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

                   List list = new ArrayList();

                   list.add(new User("高淇","123"));

                   list.add(new User("马士兵","456"));

                  

                   return list;

         }

        

}

 

 

5.      测试。

a)        启动服务器。输入:http://localhost:8080/springmvc03/a.jsp

 

 

 

 

 

 

Spring中的拦截器

定义spring拦截器两种基本方式

1.      实现接口:org.springframework.web.servlet.HandlerInterceptor。

接口中有如下方法需要重写:

注意:参数中的Object handler是下一个拦截器。

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

该方法在action执行前执行,可以实现对数据的预处理,比如:编码、安全控制等。

如果方法返回true,则继续执行action。

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

该方法在action执行后,生成视图前执行。在这里,我们有机会修改视图层数据。

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

最后执行,通常用于释放资源,处理异常。我们可以根据ex是否为空,来进行相关的异常处理。因为我们在平时处理异常时,都是从底层向上抛出异常,最后到了spring框架从而到了这个方法中。

2.      继承适配器:
org.springframework.web.servlet.handler.HandlerInterceptorAdapter

这个适配器实现了HandlerInterceptor接口。提供了这个接口中所有方法的空实现。

 

如下我们写出两个拦截器的示例代码,仅供大家参考:

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("最后执行!!!一般用于释放资源!!");

      

    }

 

    @Override

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

       System.out.println("Action执行之后,生成视图之前执行!!");

    }

 

    @Override

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

       System.out.println("action之前执行!!!");

       return true//继续执行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//继续执行action

    }

 

}

 

 

 

3.      XML中如何配置。如下为示例代码:

    <mvc:interceptors>

       <bean class="com.sxt.interceptor.MyInterceptor">bean>

       <mvc:interceptor>

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

          

           <bean class="com.sxt.interceptor.MyInterceptor2">bean>

       mvc:interceptor>

    mvc:interceptors>

 

 


 [1]将属性u的值赋给形参uname

 [2]一定要加。

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