整合SSM

环境要求

  1. 环境要求
  2. 环境：
  4. IDEA
  6. MySQL 5.7.19
  8. Tomcat 9
  10. Maven 3.6
  12.  要求：
  14. 需要熟练掌握MySQL数据库，Spring，JavaWeb及MyBatis知识，简单的前端知识；

数据库环境

创建一个存放书籍数据的数据库表

CREATE DATABASE `ssmbuild`;

USE `ssmbuild`;

DROP TABLE IF EXISTS `books`;

CREATE TABLE `books` (
`bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` VARCHAR(100) NOT NULL COMMENT '书名',
`bookCounts` INT(11) NOT NULL COMMENT '数量',
`detail` VARCHAR(200) NOT NULL COMMENT '描述',
KEY `bookID` (`bookID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8

INSERT  INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES
(1,'Java',1,'从入门到放弃'),
(2,'MySQL',10,'从删库到跑路'),
(3,'Linux',5,'从进门到进牢');

基本环境搭建

1、新建一Maven项目！ssmbuild ， 添加web的支持

2、导入相关的pom依赖！

<dependencies>
   <!--Junit-->
   <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>4.12</version>
   </dependency>
   <!--数据库驱动-->
   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
       <version>5.1.47</version>
   </dependency>
   <!-- 数据库连接池 -->
   <dependency>
       <groupId>com.mchange</groupId>
       <artifactId>c3p0</artifactId>
       <version>0.9.5.2</version>
   </dependency>

   <!--Servlet - JSP -->
   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>servlet-api</artifactId>
       <version>2.5</version>
   </dependency>
   <dependency>
       <groupId>javax.servlet.jsp</groupId>
       <artifactId>jsp-api</artifactId>
       <version>2.2</version>
   </dependency>
   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>jstl</artifactId>
       <version>1.2</version>
   </dependency>

   <!--Mybatis-->
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis</artifactId>
       <version>3.5.2</version>
   </dependency>
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis-spring</artifactId>
       <version>2.0.2</version>
   </dependency>

   <!--Spring-->
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-webmvc</artifactId>
       <version>5.1.9.RELEASE</version>
   </dependency>
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-jdbc</artifactId>
       <version>5.1.9.RELEASE</version>
   </dependency>
</dependencies>

3、Maven资源过滤设置

<build>
   <resources>
       <resource>
           <directory>src/main/java</directory>
           <includes>
               <include>**/*.properties</include>
               <include>**/*.xml</include>
           </includes>
           <filtering>false</filtering>
       </resource>
       <resource>
           <directory>src/main/resources</directory>
           <includes>
               <include>**/*.properties</include>
               <include>**/*.xml</include>
           </includes>
           <filtering>false</filtering>
       </resource>
   </resources>
</build>

建立基本结构和配置框架！

  • com.kuang.pojo
  • com.kuang.dao
  • com.kuang.service
  • com.kuang.controller
  • mybatis-config.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>

    <settings>
        <!-- 开启下划线映射驼峰命名 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!-- 开启内嵌关联对象的懒加载(使用时再加载) -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 开启内嵌关联对象的轻度懒加载(只要外部对象的任一方法被调用, 就完全加载所有内嵌的关联对象) -->
        <setting name="aggressiveLazyLoading" value="true"/>
        <!-- 将null值映射为Jdbc类型的NULL, 而不是Other -->
        <setting name="jdbcTypeForNull" value="NULL"/>
        <!-- 加载所有映射文件中配置的全局缓存 -->
        <setting name="cacheEnabled" value="true"/>
        <!-- 设置对于枚举类型, 默认使用哪个类型处理器, 默认是EnumTypeHandler -->
        <!--<setting name="defaultEnumTypeHandler" value="com.xxx.xxx.MyEnumTypeHandler"/>-->
        <!-- 打印SQL语句到控制台 -->
<!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
    </settings>

    <!-- 类型别名 -->
    <typeAliases>
        <package name="com.xuge.crud.pojo"/>
    </typeAliases>
<!--    <plugins>-->
<!--        &lt;!&ndash;设置分页插件&ndash;&gt;-->
<!--        <plugin interceptor="com.github.pagehelper.PageInterceptor" />-->
<!--    </plugins>-->

</configuration>

applicationContext.xml

<?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"
       xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd
        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-4.3.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
    <!--导入配置文件-->
    <import resource="classpath:spring-dao.xml"/>
    <import resource="spring-service.xml" />
    <import resource="spring-mvc.xml" />
</beans>

Mybatis层编写

1、数据库配置文件 druid.properties

jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8
jdbc.username=root
jdbc.password=609483
jdbc.driverClassName=com.mysql.jdbc.Driver
#监控统计用filter:stat, 日志用filter:log4j, 防御sql注入用filter:wall
jdbc.filters=stat
#最大连接数
jdbc.maxActive=20
#初始连接数
jdbc.initialSize=1
#获得连接时的最大等待时间
jdbc.minIdle=1
#它有两个作用:
#1.有个【Destroy线程】会每隔timeBetweenEvictionRunsMillis毫秒检测一下连接的空闲时间，如果连接空闲时间大于等于minEvictableIdleTimeMillis则关闭连接, 直到连接池中的连接数为minIdle为止
#2.它也是testWhileIdle的判断依据，详细看testWhileIdle属性的说明
jdbc.timeBetweenEvictionRunsMillis=60000
#连接保持空闲而不被关闭的最小时间
jdbc.minEvictableIdleTimeMillis=300000
#用来检测连接是否有效的sql，要求是一个查询语句，常用select 'x'。
#如果validationQuery为null，testOnBorrow、testOnReturn、testWhileIdle都不会起作用。
jdbc.validationQuery=select 'x
#申请连接时,若连接的空闲时间>timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。
jdbc.testWhileIdle=true
#申请连接时是否执行validationQuery
jdbc.testOnBorrow=false
#归还连接时是否执行validationQuery
jdbc.testOnReturn=false
#是否缓存PreparedStatement对象(mysql下false, oracle下true)
jdbc.poolPreparedStatements=false
#每个Connection能缓存的PreparedStatement的最大个数
jdbc.maxPoolPreparedStatementPerConnectionSize=-1

2、IDEA关联数据库

3、编写MyBatis的核心配置文件

<?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>

    <settings>
        <!-- 开启下划线映射驼峰命名 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!-- 开启内嵌关联对象的懒加载(使用时再加载) -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 开启内嵌关联对象的轻度懒加载(只要外部对象的任一方法被调用, 就完全加载所有内嵌的关联对象) -->
        <setting name="aggressiveLazyLoading" value="true"/>
        <!-- 将null值映射为Jdbc类型的NULL, 而不是Other -->
        <setting name="jdbcTypeForNull" value="NULL"/>
        <!-- 加载所有映射文件中配置的全局缓存 -->
        <setting name="cacheEnabled" value="true"/>
        <!-- 设置对于枚举类型, 默认使用哪个类型处理器, 默认是EnumTypeHandler -->
        <!--<setting name="defaultEnumTypeHandler" value="com.xxx.xxx.MyEnumTypeHandler"/>-->
        <!-- 打印SQL语句到控制台 -->
<!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
    </settings>

    <!-- 类型别名 -->
    <typeAliases>
        <package name="com.xuge.crud.pojo"/>
    </typeAliases>
<!--    <plugins>-->
<!--        &lt;!&ndash;设置分页插件&ndash;&gt;-->
<!--        <plugin interceptor="com.github.pagehelper.PageInterceptor" />-->
<!--    </plugins>-->

</configuration>

4、编写数据库对应的实体类 com.xuge.crud.pojo.Books使用lombok插件！

package com.kuang.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {

   private int bookID;
   private String bookName;
   private int bookCounts;
   private String detail;

}

5、编写Dao层的 Mapper接口！

package com.xuge.crud.mappers;

import com.xuge.crud.pojo.Books;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * author: yjx
 * Date :2022/3/1016:46
 **/
public interface BookMapper {
  //增加一本书
  int insertBook(Books book);
  //删除一本书
  int delBook(@Param("id")Integer id);
  //修改一本书
  int updateBook(Books book);
  //查询一本书
  Books queryBookById(@Param("id")Integer id);
  //查询全部书
  List<Books> queryAllBook();

}

6、编写接口对应的 Mapper.xml 文件。需要导入MyBatis的包；

<?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.xuge.crud.mappers.BookMapper">
    <!--//增加一本书-->
    <!--int insertBook(Books book);-->
    <insert id="insertBook" parameterType="Books">
        insert into t_book values(null,#{bookName},#{bookCounts},#{detail});
    </insert>
    <!--根据id删除一个Book-->
    <delete id="delBook" parameterType="int">
      delete from t_book  where bookID=#{id}
   </delete>

    <!--更新Book-->
    <update id="updateBook" parameterType="Books">
      update t_book
      set bookName = #{bookName},bookCounts = #{bookCounts},detail = #{detail}
      where bookId = #{bookId}
   </update>

    <!--根据id查询,返回一个Book-->
    <select id="queryBookById" resultType="Books">
      select * from t_book
      where bookId = #{id}
   </select>

    <!--查询全部Book-->
    <select id="queryAllBook" resultType="Books">
      SELECT * from t_book
   </select>

</mapper>

7、编写Service层的接口和实现类

接口：

package com.xuge.crud.service;

import com.xuge.crud.pojo.Books;

import java.util.List;

/**
 * author: yjx
 * Date :2022/3/1016:58
 **/
public interface BookService {
  //增加一个Book
  int addBook(Books book);
  //根据id删除一个Book
  int deleteBookById(int id);
  //更新Book
  int updateBook(Books books);
  //根据id查询,返回一个Book
  Books queryBookById(int id);
  //查询全部Book,返回list集合
  List<Books> queryAllBook();
}

实现类:

package com.xuge.crud.service.Impl;

import com.xuge.crud.mappers.BookMapper;
import com.xuge.crud.pojo.Books;
import com.xuge.crud.service.BookService;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * author: yjx
 * Date :2022/3/1016:59
 **/
@Service
public class BookServiceImpl implements BookService {
  @Autowired
  private BookMapper bookMapper;
  @Override
  public int addBook(Books book) {
    return bookMapper.insertBook(book);
  }

  @Override
  public int deleteBookById(@Param("id")int id) {
    return bookMapper.delBook(id);
  }

  @Override
  public int updateBook(Books books) {
    return bookMapper.updateBook(books);
  }

  @Override
  public Books queryBookById(@Param("id")int id) {
    return bookMapper.queryBookById(id);
  }

  @Override
  public List<Books> queryAllBook() {
    return bookMapper.queryAllBook();
  }
}

OK，到此，底层需求操作编写完毕！

Spring层

1、配置Spring整合MyBatis，我们这里数据源使用druid连接池；

2、我们去编写Spring整合Mybatis的相关的配置文件；spring-dao.xml

<?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
       https://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 配置整合mybatis -->
    <!-- 1.关联数据库文件 -->
    <context:property-placeholder location="classpath:druid.properties"/>
    <!-- 2.数据库连接池 -->
    <!--数据库连接池
        dbcp 半自动化操作 不能自动连接
        c3p0 自动化操作（自动的加载配置文件 并且设置到对象里面）
        druid
    -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="driverClassName" value="${jdbc.driverClassName"}/>
        <property name="filters" value="${jdbc.filters}"/>
        <property name="initialSize" value="${jdbc.initialSize}"/>
        <property name="maxActive" value="${jdbc.maxActive}"/>
        <property name="minIdle" value="${jdbc.minIdle}"/>
        <property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/>
        <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/>
        <property name="validationQuery" value="${jdbc.validationQuery}"/>
        <property name="testWhileIdle" value="${jdbc.testWhileIdle}"/>
        <property name="testOnBorrow" value="${jdbc.testOnBorrow}"/>
        <property name="testOnReturn" value="${jdbc.testOnReturn}"/>
        <property name="poolPreparedStatements" value="${jdbc.poolPreparedStatements}"/>
        <property name="maxPoolPreparedStatementPerConnectionSize"
                  value="${jdbc.maxPoolPreparedStatementPerConnectionSize}"/>
    </bean>

    <!--3.配置sqlSessionFactory对象-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--注入数据库连接池-->
        <property name="dataSource" ref="dataSource"/>
        <!--配置mybatis核心配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml" />
    </bean>

    <!-- 4.配置扫描Dao接口包，动态实现Dao接口注入到spring容器中 -->
    <!--解释 ：https://www.cnblogs.com/jpfss/p/7799806.html-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--注入sqlSessionFactory对象-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
        <!--给出要扫描的dao接口包路径-->
        <property name="basePackage" value="com.xuge.crud.mapper" />
    </bean>


</beans>

3、Spring整合service层

<?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">

    <!--1.扫描service相关的bean -->
    <context:component-scan base-package="com.xuge.crud.service" />
    <!--将我们所有的service层的类加入到spring中-->
    <!--2.配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!--注入数据库连接池-->
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

Spring层搞定！再次理解一下，Spring就是一个大杂烩，一个容器！对吧！

SpringMVC层

1、web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
        version="4.0">

   <!--DispatcherServlet-->
   <servlet>
       <servlet-name>DispatcherServlet</servlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
       <init-param>
           <param-name>contextConfigLocation</param-name>
           <!--一定要注意:我们这里加载的是总的配置文件，之前被这里坑了！-->  
           <param-value>classpath:applicationContext.xml</param-value>
       </init-param>
       <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet-mapping>
       <servlet-name>DispatcherServlet</servlet-name>
       <url-pattern>/</url-pattern>
   </servlet-mapping>

   <!--encodingFilter-->
   <filter>
       <filter-name>encodingFilter</filter-name>
       <filter-class>
          org.springframework.web.filter.CharacterEncodingFilter
       </filter-class>
       <init-param>
           <param-name>encoding</param-name>
           <param-value>utf-8</param-value>
       </init-param>
   </filter>
   <filter-mapping>
       <filter-name>encodingFilter</filter-name>
       <url-pattern>/*</url-pattern>
   </filter-mapping>

   <!--Session过期时间-->
   <session-config>
       <session-timeout>15</session-timeout>
   </session-config>

</web-app>

2、spring-mvc.xml

<?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"
      xmlns:mvc="http://www.springframework.org/schema/mvc"
      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
   http://www.springframework.org/schema/mvc
   https://www.springframework.org/schema/mvc/spring-mvc.xsd">

   <!-- 配置SpringMVC -->
   <!-- 1.开启SpringMVC注解驱动 -->
   <mvc:annotation-driven />
   <!-- 2.静态资源默认servlet配置-->
   <mvc:default-servlet-handler/>

   <!-- 3.配置jsp 显示ViewResolver视图解析器 -->
   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
       <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
       <property name="prefix" value="/WEB-INF/jsp/" />
       <property name="suffix" value=".jsp" />
   </bean>

   <!-- 4.扫描web相关的bean -->
   <context:component-scan base-package="com.kuang.controller" />

</beans>

3、Spring配置整合文件，applicationContext.xml

<?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.xsd">

   <import resource="spring-dao.xml"/>
   <import resource="spring-service.xml"/>
   <import resource="spring-mvc.xml"/>

</beans>

配置文件，暂时结束！Controller 和 视图层编写

BookController 类编写

方法一：查询全部书籍

1.list方法

@Controller
@RequestMapping("/book")
public class BookController {

   @Autowired
   @Qualifier("BookServiceImpl")
   private BookService bookService;

   @RequestMapping("/allBook")
   public String list(Model model) {
       List<Books> list = bookService.queryAllBook();
       model.addAttribute("list", list);
       return "allBook";
  }
}

2、编写首页 index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE HTML>
<html>
<head>
   <title>首页</title>
   <style type="text/css">
       a {
           text-decoration: none;
           color: black;
           font-size: 18px;
      }
       h3 {
           width: 180px;
           height: 38px;
           margin: 100px auto;
           text-align: center;
           line-height: 38px;
           background: deepskyblue;
           border-radius: 4px;
      }
   </style>
</head>
<body>

<h3>
   <a href="${pageContext.request.contextPath}/book/allBook">点击进入列表页</a>
</h3>
</body>
</html>

3.bean不存在

解决方案
*查看这个bean是否注入成功*ok
*junit单元测试，看代码是否可用*ok
*问题一定不在我们的底层，而是spring出了问题ok
*SpringMVC整合的时候没有调用到我们的sercice层的bean
 1.applicationContext.xml没有注入service层的bean
 2.web.xml中配置问题

4、书籍列表页面 allbook.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <title>书籍列表</title>
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <!-- 引入 Bootstrap -->
   <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>

<div class="container">

   <div class="row clearfix">
       <div class="col-md-12 column">
           <div class="page-header">
               <h1>
                   <small>书籍列表 —— 显示所有书籍</small>
               </h1>
           </div>
       </div>
   </div>

   <div class="row">
       <div class="col-md-4 column">
           <a class="btn btn-primary" href="${pageContext.request.contextPath}/book/toAddBook">新增</a>
       </div>
   </div>

   <div class="row clearfix">
       <div class="col-md-12 column">
           <table class="table table-hover table-striped">
               <thead>
               <tr>
                   <th>书籍编号</th>
                   <th>书籍名字</th>
                   <th>书籍数量</th>
                   <th>书籍详情</th>
                   <th>操作</th>
               </tr>
               </thead>

               <tbody>
               <c:forEach var="book" items="${requestScope.get('list')}">
                   <tr>
                       <td>${book.getBookID()}</td>
                       <td>${book.getBookName()}</td>
                       <td>${book.getBookCounts()}</td>
                       <td>${book.getDetail()}</td>
                       <td>
                           <a href="${pageContext.request.contextPath}/book/toUpdateBook?id=${book.getBookID()}">更改</a> |
                           <a href="${pageContext.request.contextPath}/book/del/${book.getBookID()}">删除</a>
                       </td>
                   </tr>
               </c:forEach>
               </tbody>
           </table>
       </div>
   </div>
</div>

方法二：添加书籍

@RequestMapping("/toAddBook")
public String toAddPaper() {
   return "addBook";
}

@RequestMapping("/addBook")
public String addPaper(Books books) {
   System.out.println(books);
   bookService.addBook(books);
   return "redirect:/book/allBook";
}

5、添加书籍页面：addBook.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
   <title>新增书籍</title>
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <!-- 引入 Bootstrap -->
   <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">

   <div class="row clearfix">
       <div class="col-md-12 column">
           <div class="page-header">
               <h1>
                   <small>新增书籍</small>
               </h1>
           </div>
       </div>
   </div>
   <form action="${pageContext.request.contextPath}/book/addBook" method="post">
      书籍名称：<input type="text" name="bookName"><br><br><br>
      书籍数量：<input type="text" name="bookCounts"><br><br><br>
      书籍详情：<input type="text" name="detail"><br><br><br>
       <input type="submit" value="添加">
   </form>

</div>

方法三：修改书籍

@RequestMapping("/toUpdateBook")
public String toUpdateBook(Model model, int id) {
   Books books = bookService.queryBookById(id);
   System.out.println(books);
   model.addAttribute("book",books );
   return "updateBook";
}

@RequestMapping("/updateBook")
public String updateBook(Model model, Books book) {
   System.out.println(book);
   bookService.updateBook(book);
   Books books = bookService.queryBookById(book.getBookID());
   model.addAttribute("books", books);
   return "redirect:/book/allBook";
}

7、修改书籍页面 updateBook.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <title>修改信息</title>
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <!-- 引入 Bootstrap -->
   <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">

   <div class="row clearfix">
       <div class="col-md-12 column">
           <div class="page-header">
               <h1>
                   <small>修改信息</small>
               </h1>
           </div>
       </div>
   </div>

   <form action="${pageContext.request.contextPath}/book/updateBook" method="post">
       <input type="hidden" name="bookID" value="${book.getBookID()}"/>
      书籍名称：<input type="text" name="bookName" value="${book.getBookName()}"/>
      书籍数量：<input type="text" name="bookCounts" value="${book.getBookCounts()}"/>
      书籍详情：<input type="text" name="detail" value="${book.getDetail() }"/>
       <input type="submit" value="提交"/>
   </form>

</div>

方法四：删除书籍

@RequestMapping("/del/{bookId}")
public String deleteBook(@PathVariable("bookId") int id) {
   bookService.deleteBookById(id);
   return "redirect:/book/allBook";
}

目前为止，这个SSM项目整合已经完全的OK了，可以直接运行进行测试！这个练习十分的重要，大家需要保证，不看任何东西，自己也可以完整的实现出来！

项目结构图

SSM_CRUD - 图1

小结及展望

这个是同学们的第一个SSM整合案例，一定要烂熟于心！

SSM框架的重要程度是不言而喻的，学到这里，大家已经可以进行基本网站的单独开发。但是这只是增删改查的基本操作。可以说学到这里，大家才算是真正的步入了后台开发的门。也就是能找一个后台相关工作的底线。

或许很多人，工作就做这些事情，但是对于个人的提高来说，还远远不够！

我们后面还要学习一些 SpringMVC 的知识！

Ajax   和   Json

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