Spring与Web

时间：2023-03-09 20:37:15
Spring与Web

一、定义页面及Servlet

在jsp页面加入以下，避免乱码

<meta charset="utf-8">
<body>

    <form action="RegisterServlte" method="post">

        姓名：<input type="text" name="name" /><br>

        年龄：<input type="text" name="age" /><br>

        <input type="submit" value="注册" />

    </form>

  </body>
import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.jmu.beans.Student;

/**

 * Servlet implementation class RegisterServlte

 */

public class RegisterServlte extends HttpServlet {

    private static final long serialVersionUID = 1L;

    /**

     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)

     */

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // TODO Auto-generated method stub

        doPost(request, response);

    }

    /**

     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

     */

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // TODO Auto-generated method stub

        request.setCharacterEncoding("utf-8");

        String name=request.getParameter("name");

        String ageStr=request.getParameter("age");

        Integer age=Integer.valueOf(ageStr);

        Student student=new Student(name,age);

        request.getRequestDispatcher("/welcome.jsp").forward(request, response);

    }

}

三、测试环境搭建

Spring与Web

 public class Student {

     private Integer id;

     private String name;

     private int age;

     public Student() {

         super();

     }

     public Student( String name, int age) {

         super();

         this.name = name;

         this.age = age;

     }

     public Integer getId() {

         return id;

     }

     public void setId(Integer id) {

         this.id = id;

     }

     public String getName() {

         return name;

     }

     public void setName(String name) {

         this.name = name;

     }

     public int getAge() {

         return age;

     }

     public void setAge(int age) {

         this.age = age;

     }

     @Override

     public String toString() {

         return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";

     }

 }

Student

 //Dao增删改查

 public interface IStudentDao {

     void insertStudent(Student student);

     void deleteById(int id);

     void updateStudent(Student student);

     List<Student> selectAllStudents();

     Student selectStudentById(int id);

 }

IStudentDao

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

 <!DOCTYPE mapper

 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

 <mapper namespace="com.jmu.dao.IStudentDao">

     <insert id="insertStudent">

         insert into student(name,age) values(#{name},#{age})

     </insert>

     <delete id="deleteById">

         delete from student where id=#{XXX}

     </delete>

     <update id="updateStudent">

         update student set name=#{name},age=#{age} where id=#{id}

     </update>

     <select id="selectAllStudents" resultType="student">

         select id,name,age from student

     </select>

     <select id="selectStudentById" resultType="student">

         select id,name,age from student where id=#{XXX}

     </select>

 </mapper>

IStudentDao.xml

IStudentService
 public class StudentServiceImpl implements IStudentService {

     private IStudentDao dao;

     public void setDao(IStudentDao dao) {

         this.dao = dao;

     }

     public void addStudent(Student student) {

         // TODO Auto-generated method stub

         dao.insertStudent(student);

     }

     public void removeById(int id) {

         // TODO Auto-generated method stub

         dao.deleteById(id);

     }

     public void modifyStudent(Student student) {

         // TODO Auto-generated method stub

         dao.updateStudent(student);

     }

     public List<String> findAllStudentsNames() {

         // TODO Auto-generated method stub

         List<String> names = new ArrayList<String>();

         List<Student> sudents = this.findAllStudents();

         for (Student student : sudents) {

           names.add(student.getName());

         }

         return names;

     }

     public String findStudentNameById(int id) {

         // TODO Auto-generated method stub

         Student student = this.findStudentById(id);

         return student.getName();

     }

     public List<Student> findAllStudents() {

         // TODO Auto-generated method stub

         return dao.selectAllStudents();

     }

     public Student findStudentById(int id) {

         // TODO Auto-generated method stub

         return dao.selectStudentById(id);

     }

 }

StudentServiceImpl

// 获取Spring容器对象

        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");

        // 从Spring容器中获取到service对象

        IStudentService service = (IStudentService) ac.getBean("studentService");

        // 调用Service的addStudent()完成插入

        service.addStudent(student);

RegisterServlet

 <?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:context="http://www.springframework.org/schema/context"

     xsi:schemaLocation="

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

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

     <!--注册数据源:C3P0 -->

     <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

         <property name="driverClass" value="${jdbc.driver}" />

         <property name="jdbcUrl" value="${jdbc.url}" />

         <property name="user" value="${jdbc.user}" />

         <property name="password" value="${jdbc.password}" />

     </bean>

     <!-- 注册属性文件 -->

     <context:property-placeholder location="classpath:jdbc.properties" />

     <bean id="mySqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

        <property name="configLocation" value="classpath:mybatis.xml"></property>

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

     </bean>

     <!--生成Dao的代理对象

      当前配置会被本包中所有的接口生成代理对象

     -->

     <bean  class="org.mybatis.spring.mapper.MapperScannerConfigurer">

         <property name="sqlSessionFactoryBeanName" value="mySqlSessionFactory" />

         <property name="basePackage" value="com.jmu.dao" />

     </bean>

     <!-- 注册Service -->

     <bean id="studentService" class="com.jmu.service.StudentServiceImpl">

          <!-- 这里的Dao的注入需要使用ref属性，且其作为接口的简单类名 -->

         <property name="dao" ref="IStudentDao" />

     </bean>

 </beans>

applicationContext.xml

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

 <!DOCTYPE configuration

 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

 "http://mybatis.org/dtd/mybatis-3-config.dtd">

 <configuration>

     <!--配置别名 -->

     <typeAliases>

         <package name="com.jmu.beans" />

     </typeAliases>

     <mappers>

         <package name="com.jmu.dao" />

     </mappers>

 </configuration>

mybatis.xml

Spring与WebSpring与Web

四、当前程序存在问题

刷新会创建不同spring容器对象，而不同servlet创建不同容器。当一个应用只能有一个spring容器

五、注册ContextLoaderListener

复制之前web项目，需要修改web context root

ctrl+shift+t open Type

ctrl+o 查看结构

ctrl+t 查看继承关系

myeclipse快捷键

方法一：读源码ContextLoaderListener与ContextLoader获取key

注册ServletContext监听器，完成2件工作：

1、在Servletcontext被创建时，创建Spring容器对象；

2、将创建好的Spring容器对象放入到ServletContext的域属性空间

<listener>

    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>

修改applicationContext.xml为spring.xml在web.xml中添加如下(Spring在web项目中必须有的2项配置)：

 <context-param>

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

    <param-value>classpath:spring.xml</param-value>

  </context-param>

<!--   注册servletContext监听器 -->

  <listener>

    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

  </listener>

修改servlet中

    // 获取Spring容器对象

        String acKey = WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE;

        ApplicationContext ac = (ApplicationContext) this.getServletContext().getAttribute(acKey);
 public class RegisterServlet extends HttpServlet {

     private static final long serialVersionUID = 1L;

     /**

      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse

      *      response)

      */

     protected void doGet(HttpServletRequest request, HttpServletResponse response)

             throws ServletException, IOException {

         // TODO Auto-generated method stub

         doPost(request, response);

     }

     /**

      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse

      *      response)

      */

     protected void doPost(HttpServletRequest request, HttpServletResponse response)

             throws ServletException, IOException {

         // TODO Auto-generated method stub

         request.setCharacterEncoding("utf-8");

         String name = request.getParameter("name");

         String ageStr = request.getParameter("age");

         Integer age = Integer.valueOf(ageStr);

         Student student = new Student(name, age);

         // 获取Spring容器对象

         String acKey = WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE;

         ApplicationContext ac = (ApplicationContext) this.getServletContext().getAttribute(acKey);

         // 从Spring容器中获取到service对象

         IStudentService service = (IStudentService) ac.getBean("studentService");

         // 调用Service的addStudent()完成插入

         service.addStudent(student);

         request.getRequestDispatcher("/welcome.jsp").forward(request, response);

     }

 }

RegisterServlet

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

 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

   <display-name>17-spring-web</display-name>

   <welcome-file-list>

     <welcome-file>index.jsp</welcome-file>

   </welcome-file-list>

   <context-param>

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

     <param-value>classpath:spring.xml</param-value>

   </context-param>

 <!--   注册servletContext监听器 -->

   <listener>

     <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

   </listener>

   <servlet>

     <description></description>

     <display-name>RegisterServlet</display-name>

     <servlet-name>RegisterServlet</servlet-name>

     <servlet-class>com.jmu.servlets.RegisterServlet</servlet-class>

   </servlet>

   <servlet-mapping>

     <servlet-name>RegisterServlet</servlet-name>

     <url-pattern>/RegisterServlet</url-pattern>

   </servlet-mapping>

   <servlet>

     <description></description>

     <display-name>LoginServlet</display-name>

     <servlet-name>LoginServlet</servlet-name>

     <servlet-class>com.jmu.servlets.LoginServlet</servlet-class>

   </servlet>

   <servlet-mapping>

     <servlet-name>LoginServlet</servlet-name>

     <url-pattern>/LoginServlet</url-pattern>

   </servlet-mapping>

 </web-app>

web.xml

方法二：使用工具类获取Spring容器

修改servlet中

    // 获取Spring容器对象

        WebApplicationContext ac= WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());

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