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SpringMVC轻松学习-注解的使用（三）

2024-07-02 01:37:55   227人阅读

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=http://www.mamicode.com/"<%=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=http://www.mamicode.com/"styles.css">
    -->
  </head>
    
  <body>
<form action="user.do">
  用户名：<input type=text name=uname /><br/>
<input type=hidden name=method value=http://www.mamicode.com/reg />
<input type=submit value=http://www.mamicode.com/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=http://www.mamicode.com/"<%=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=http://www.mamicode.com/"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






















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