SpringMVC轻松学习-注解的使用（三）

根据上一讲的例子，我们下面就注解的使用进行详细说明。

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。

修改web.xml，文件内容如下：

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<?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>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配置内容如下：

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<?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">            <!-- 对web包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->     <context:component-scan base-package="com.sxt"/>       <!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->     <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>       <!--对模型视图名称的解析，即在模型视图名称添加前后缀 -->     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"         p:suffix=".jsp"/> </beans>

hib-config.xml(配置了spring集成hibernate)

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<?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"/>       <!-- 支持aop注解 -->     <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>                  <!-- key的名字前面都要加hibernate. -->                    <prop key="hibernate.dialect">                         org.hibernate.dialect.MySQLDialect                     </prop>                     <prop key="hibernate.show_sql">true</prop>                    <prop key="hibernate.hbm2ddl.auto">update</prop>                </props>            </property>         <property name="packagesToScan">             <value>com.sxt.po</value>         </property>    </bean>    <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate" >     <property name="sessionFactory" ref="sessionFactory"></property> </bean>   <!--配置一个JdbcTemplate实例-->  <bean id="jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate">        <property name="dataSource" ref="dataSource"/>   </bean>      <!-- 配置事务管理 --> <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"  />         <!-- get开头的方法不需要在事务中运行 。         有些情况是没有必要使用事务的，比如获取数据。开启事务本身对性能是有一定的影响的-->         <tx:method name="*"/>    <!-- 其他方法在实务中运行 -->     </tx:attributes> </tx:advice>   </beans>

reg.jsp如下

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<%@ 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 page</title>     <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">     <!--     <link rel="stylesheet" type="text/css" href="styles.css">     -->   </head>        <body> <form action="user.do">   用户名：<input type=text name=uname /><br/> <input type=hidden name=method value=reg /> <input type=submit value=注册 /> </form>   </body> </html>

index.jsp 如下：

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<%@ 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 page</title>     <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">     <!--     <link rel="stylesheet" type="text/css" href="styles.css">     -->   </head>       <body>    <h1>**********${params.uname}</h1>    <h1>**********${requestScope.u}</h1>    <h1>**********${requestScope.user}</h1>   </body> </html>

User.java

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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;     }             }

UserDao.java

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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;     }       }

UserService.Java

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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;     }       }

UserController.java

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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")//这里的 @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;     }         }

说明：

• @Controller("userController")这里也可以使用component进行注解，这里的controller和component一样，但是一般不用component，而这样的注解还@Repository、@Service、@Controller大家估计都知道怎么使用了，不会的话看我的之前发的blog：http://www.cnblogs.com/wang3680/p/0f4eea023d8eb01b097c732fddba5725.html
• @RequestMapping("/user.do") 注解说明：这个注解是页面提交到user.dao中进行操作的controller，之前我们的controller还需要进行实现controller接口，而现在不需要实现此接口了，而且controller里面的函数也不需要去复写handleRequest方法了，这里我们就可以自己写自己的方法了，但是我们怎么知道页面提交给那个方法了呢？
• @RequestMapping(params="method=reg")说明：这个注解就是去解释页面提交的给了那个方法的，就是提交来的带有method=reg的就会调转到此方法中,我们上面的页面中是这样定义传值的<input type=hidden name=method value=reg />
• 问题又来啦，struts2中我们是根据属性的set和get方法得到我们传递来的值得，这里怎么办呢？我们在controller方法中添加参数将传递的值传递来，public String reg(String uname) 这里的命名必须和页面传来的对应上。

上面的controller中，我们传递的是uname，我们这样呢，将参数改成User user为public String reg(User user)

 

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@RequestMapping(params="method=reg2")    public String reg(User user) {        System.out.println("HelloController.handleRequest()");        userService.add(user.getUname());        return "index";    }

说明：

这里呢其实是将User模型中的属性拿来用了，我们必须保证页面定义的名称和模型中的一样才行，这一点类此与struts2里面的模型驱动

来自为知笔记(Wiz)