基本环境的构建

新建Maven项目，添加web支持。导入依赖，一个简单的CRUD项目所需导入的依赖 junit、数据库、连接池、servlet、jsp、mybatis、mybatis-spring、spring。

  1.         <dependencies>
  2.         <!--junit 依赖-->
  3.         <dependency>
  4.             <groupId>junit</groupId>
  5.             <artifactId>junit</artifactId>
  6.             <version>4.13.2</version>
  7.         </dependency>
  8.         <!--数据库驱动 依赖-->
  9.         <dependency>
  10.             <groupId>mysql</groupId>
  11.             <artifactId>mysql-connector-java</artifactId>
  12.             <version>8.0.23</version>
  13.         </dependency>
  14.         <!--连接池 依赖-->
  15.         <dependency>
  16.             <groupId>com.mchange</groupId>
  17.             <artifactId>c3p0</artifactId>
  18.             <version>0.9.5.5</version>
  19.         </dependency>
  20.         <!--servlet-jsp 依赖-->
  21.         <dependency>
  22.             <groupId>javax.servlet</groupId>
  23.             <artifactId>servlet-api</artifactId>
  24.             <version>2.5</version>
  25.         </dependency>
  26.         <dependency>
  27.             <groupId>javax.servlet</groupId>
  28.             <artifactId>servlet-api</artifactId>
  29.             <version>2.2</version>
  30.         </dependency>
  31.         <dependency>
  32.             <groupId>javax.servlet</groupId>
  33.             <artifactId>jstl</artifactId>
  34.             <version>1.2</version>
  35.         </dependency>
  36.         <!--mybatis 依赖-->
  37.         <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
  38.         <dependency>
  39.             <groupId>org.mybatis</groupId>
  40.             <artifactId>mybatis</artifactId>
  41.             <version>3.5.6</version>
  42.         </dependency>
  43.         <!--mybatis-spring 依赖-->
  44.         <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
  45.         <dependency>
  46.             <groupId>org.mybatis</groupId>
  47.             <artifactId>mybatis-spring</artifactId>
  48.             <version>2.0.6</version>
  49.         </dependency>
  50.         <!--spring 依赖-->
  51.         <dependency>
  52.             <groupId>org.springframework</groupId>
  53.             <artifactId>spring-webmvc</artifactId>
  54.             <version>5.3.5</version>
  55.         </dependency>
  56.         <dependency>
  57.             <groupId>org.springframework</groupId>
  58.             <artifactId>spring-jdbc</artifactId>
  59.             <version>5.3.5</version>
  60.         </dependency>
  62.         <!--lombok 依赖-->
  63.         <dependency>
  64.             <groupId>org.projectlombok</groupId>
  65.             <artifactId>lombok</artifactId>
  66.             <version>1.18.20</version>
  67.         </dependency>
  68.         <dependency>
  69.             <groupId>junit</groupId>
  70.             <artifactId>junit</artifactId>
  71.             <version>RELEASE</version>
  72.             <scope>test</scope>
  73.         </dependency>
  74.         <dependency>
  75.             <groupId>org.jetbrains</groupId>
  76.             <artifactId>annotations-java5</artifactId>
  77.             <version>RELEASE</version>
  78.             <scope>compile</scope>
  79.         </dependency>
  81.     </dependencies>

依赖导入之后，创建一个项目的基本框架和配置文件。entity层，dao层，service层，controller层，mybatis-config.xml，以及spring配置文件的总管理applicationContext.xml。
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>

</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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">

</beans>

Mybatis层整合

1.数据库信息配置文件

数据库信息配置文件database.properties，这里使用了连接池同样在其中加入连接池配置信息。（连接池的作用：将我们已经创建了的连接存入一个缓冲池中，当有请求需要进行操作时，可以直接调用我们事先已经创建的连接进行对数据库进行操作。）

jdbc.driver=com.mysql.jdbc.Driver
#8.0MySQL数据库时区问题//&serverTimezone=Asia/Shanghai
jdbc.url=jdbc:mysql://localhost:3306/ssmintegrationdb?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai
#用户名
jdbc.username=root
#密码
jdbc.password=123456
#最大连接数
c3p0.maxPoolSize=30
#最小连接数
c3p0.minPoolSize=10
#关闭连接后不自动commit
c3p0.autoCommitOnClose=false
#获取连接超时时间
c3p0.checkoutTimeout=10000
#当获取连接失败重试次数
c3p0.acquireRetryAttempts=2

2.Mybatis配置文件

mybatis-config.xml配置信息添加（package将此路径中的映射文件都引入，mapper对操作资源的引用）。

        <typeAliases>
        <package name="com.sy.entity"/>
    </typeAliases>

    <mappers>
        <mapper resource="mapper/BookMapper.xml"/>
    </mappers>

3.数据库对应的实体类

编写数据库对应的实体类。ssm_DB.books5、ssm整合 - 图1使用了lombok的注解自动生成构造方法，最好自己构建生成（Alt+Insert）。
注：当我们通过前端收到一个请求，通过DispatchServlet（一个实现了Servlet的Servlet类，它可以获取符合要求的外部请求，并把请求分发到不同的控制器去处理，根据控制器处理后的结果，生成相应的响应发送到客户端。）把我们获取到的请求分发到controller层的不同的控制器去处理，controller层的控制器调取service层的逻辑实现方法，service层再去调dao层的接口。

package ...
import ...

@Data
@AllArgsConstructor
@NoArgsConstructor
public class BooksEntity {

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

4.Mapper及相应的mapper.xml文件

添加对应的dao层的mapper接口。

package ...
import ...

public interface BookMapper {

    //增加一本
    int addBook(BooksEntity booksEntity);
    //删除一本
    int deleteBookById(@Param("bookId") int id);
    //更新一本
    int updateBook(BooksEntity booksEntity);
    //查询一本
    BooksEntity queryBookById(@Param("bookId") int id);
    //查所有的书
    List<BooksEntity> queryAllBook();
    //根据名字查书
    List<BooksEntity> queryBookByName(@Param("bookName") String bookName);

}

编写对应mapper接口的xml配置文件。

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.sy.dao.BookMapper">
    <insert id="addBook" parameterType="BooksEntity">
        insert into ssmintegrationdb.books (bookName,bookCounts,detail)
        values (#{bookName}, #{bookCounts}, #{detail});
    </insert>

    <delete id="deleteBookById" parameterType="int">
        delete from ssmintegrationdb.books
        where bookID = #{bookId};
    </delete>

    <update id="updateBook" parameterType="BooksEntity">
        update ssmintegrationdb.books
        set bookName = #{bookName}, bookCounts = #{bookCounts}, detail = #{detail}
        where bookID = #{bookID};
    </update>

    <select id="queryBookById" resultType="BooksEntity">
        select * from ssmintegrationdb.books where bookID = #{bookId};
    </select>

    <select id="queryAllBook" resultType="BooksEntity">
        select * from ssmintegrationdb.books;
    </select>

    <select id="queryBookByName" resultType="BooksEntity">
        select * from ssmintegrationdb.books where bookName like '%' #{bookName} '%' limit 1;
    </select>
</mapper>

5.Service层接口及实现

编写service层的接口以及实现类。
接口：

package ...
import ...

@Service
public interface BookService {
    //增加一本
    int addBook(BooksEntity booksEntity);
    //删除一本
    int deleteBookById(int id);
    //更新一本
    int updateBook(BooksEntity booksEntity);
    //查询一本
    BooksEntity queryBookById(int id);
    //查所有的书
    List<BooksEntity> queryAllBook();
    //书名查书
    List<BooksEntity> queryBookByName(String bookName);
}

实现类：

package ...
import ...

public class BookServiceImpl implements BookService{

    private BookMapper bookMapper;
    public void setBookMapper(BookMapper bookMapper) {
        this.bookMapper = bookMapper;
    }

    @Override
    public int addBook(BooksEntity booksEntity) {
        return bookMapper.addBook(booksEntity);
    }

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

    @Override
    public int updateBook(BooksEntity booksEntity) {
        return bookMapper.updateBook(booksEntity);
    }

    @Override
    public BooksEntity queryBookById(int id) {
        return bookMapper.queryBookById(id);
    }

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

    @Override
    public List<BooksEntity> queryBookByName(String bookName) {
        return bookMapper.queryBookByName(bookName);
    }

}

Spring层整合

1.Spring-Dao

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">

    <!--  关联数据库配置文件  -->
    <context:property-placeholder location="classpath:database.properties"/>
    <!--连接池-->
    <bean id = "dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
          <!-- 配置连接池属性  -->
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>

        <!--c3p0连接池的私有属性-->
        <property name="maxPoolSize" value="${c3p0.maxPoolSize}"/>
        <property name="minPoolSize" value="${c3p0.minPoolSize}"/>
        <property name="autoCommitOnClose" value="${c3p0.autoCommitOnClose}"/>
        <property name="checkoutTimeout" value="${c3p0.checkoutTimeout}"/>
        <property name="acquireRetryAttempts" value="${c3p0.acquireRetryAttempts}"/>
    </bean>

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

    <!--  配置dao的接口扫描包，动态的实现了Dao接口可以注入到Spring容器中  -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--注入sqlSessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!--要扫描的dao包-->
        <property name="basePackage" value="com.sy.dao"/>
    </bean>
</beans>

2.Spring-Service

编写Spring整合Service的相关的配置文件spring-service.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">

    <!--扫描service下所有的包-->
    <context:component-scan base-package="com.sy.service"/>

    <!--将所有业务类，注入到spring，通过配置或注解实现-->
    <bean id="bookServiceImpl" class="com.sy.service.BookServiceImpl">
        <property name="bookMapper" ref="bookMapper"/>
    </bean>

    <!--声明式事务配置-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource"/>

    </bean>
</beans>

SpringMVC层整合

1.Spring-MVC

spring-mvc.xml配置SpringMVC。（开启注解驱动、静态资源过滤、视图解析、扫描web相关的bean）

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


    <!--注解驱动-->
    <mvc:annotation-driven/>
    <!--静态资源过滤-->
    <mvc:default-servlet-handler/>
    <!--视图资源解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    <!--扫描包，扫描controller-->
    <context:component-scan base-package="com.sy.controller"/>
</beans>

spring对mybatis、service以及SpringMVC的整合配置文件构建完成。将整合配置文件导入applicationContext.xml进行统一管理。

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

web.xml文件配置，主要配置DispatchServlet，增加乱码过滤防止乱码。

<?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">

    <!--DispatchServlet-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--乱码过滤-->
    <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.Controller和网页视图

2.1查询方法实现

Controller层BookController类的编写。实现方法查询所有的书籍。

package ...
import ...

@Controller
@RequestMapping("/book")
/*controller层调service层*/
public class BookController {

    @Autowired
    @Qualifier("bookServiceImpl")
    private BookService bookService;
//    private BookService bookService = new BookServiceImpl();

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

2.2展示页面编写

首页编写index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>书</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">进入</a>
  </h3>
  </body>
</html>

书籍列表页面allBook.jsp。BookController类中的allBook方法查询到的bookList表通过forEach进行遍历输出。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>这是一堆书</title>
    <link href="https://cdn.staticfile.org/twitter-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</small>
                </h1>
            </div>
        </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>书籍名称</th>
                        <th>书籍数量</th>
                        <th>书籍描述</th>
                        <th>操作</th>
                    </tr>
                </thead>


                <tbody>
                    <c:forEach var="book" items="${bookList}">
                    <tr>
                        <td>${book.bookID}</td>
                        <td>${book.bookName}</td>
                        <td>${book.bookCounts}</td>
                        <td>${book.detail}</td>
                    </tr>
                    </c:forEach>
                </tbody>
            </table>
        </div>
    </div>

</div>
</body>
</html>

2.3增书方法实现

    //跳到增加书的页面
    @RequestMapping("/toAddBook")
    public String toAddBook(){
        return "/addBook";
    }

    //增加书的请求
    @RequestMapping("/addBook")
    public String addBook(BooksEntity booksEntity){
        bookService.addBook(booksEntity);
        //添加完后，内容改变，重定向回主页面
        return "redirect:/book/allBook";
    }

2.4增加书页面

增加jsp页面：addBook.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>增加书</title>
    <link href="https://cdn.staticfile.org/twitter-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>加书</small>
                </h1>
            </div>
        </div>
    </div>

    <form action="${pageContext.request.contextPath}/book/addBook" method="post">
        <div class="form-group">
            <label for="add_BookName">书名：</label>
            <input type="text" name="bookName" class="form-control" id="add_BookName" required>
        </div>
        <div class="form-group">
            <label for="add_BookCounts">数量：</label>
            <input type="text" name="bookCounts" class="form-control" id="add_BookCounts" required>
        </div>
        <div class="form-group">
            <label for="add_BookDetail">描述：</label>
            <input type="text" name="detail" class="form-control" id="add_BookDetail" required>
        </div>
        <div class="form-group">
            <input type="submit" class="form-control" value="确定">
        </div>
    </form>
</div>
</body>
</html>

2.5更新书信息方法实现

    //跳到修改书信息的页面
    @RequestMapping("/toUpdateBook")
    public String toUpdateBook(int id,Model model){
        BooksEntity booksEntity = bookService.queryBookById(id);
        model.addAttribute("queryBook",booksEntity);
        return "/updateBook";
    }
    //修改书信息的请求
    @RequestMapping("/updateBook")
    public String updateBook(BooksEntity booksEntity){
        bookService.updateBook(booksEntity);
        return "redirect:/book/allBook";
    }

2.6更新书信息页面

增加jsp页面：updateBook.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>修改书</title>
    <link href="https://cdn.staticfile.org/twitter-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>修改书</small>
                </h1>
            </div>
        </div>
    </div>

    <form action="${pageContext.request.contextPath}/book/updateBook" method="post">
        <%--根据bookID查询，隐藏域传递ID，进行操作--%>
        <input type="hidden" name="bookID" value="${queryBook.bookID}">
        <div class="form-group">
            <label for="add_BookName">书名：</label>
            <input type="text" name="bookName" class="form-control" id="add_BookName" value="${queryBook.bookName}" required>
        </div>
        <div class="form-group">    
            <label for="add_BookCounts">数量：</label>
            <input type="text" name="bookCounts" class="form-control" id="add_BookCounts" value="${queryBook.bookCounts}" required>
        </div>
        <div class="form-group">
            <label for="add_BookDetail">描述：</label>
            <input type="text" name="detail" class="form-control" id="add_BookDetail" value="${queryBook.detail}" required>
        </div>
        <div class="form-group">
            <input type="submit" class="form-control" value="确认修改">
        </div>
    </form>
</div>
</body>
</html>

2.7删除书方法实现

        //删掉一本书通过ID    
        @RequestMapping("/deleteBook/{bookID}")
    public String deleteBook(@PathVariable("bookID") int bookID){
        bookService.deleteBookById(bookID);
        return "redirect:/book/allBook";
    }

2.8简单优化拓展

增加按书名搜索方法

    //通过书名进行查询    
    @RequestMapping("/queryBook")
    public String queryBook(String queryBookName,Model model){
        if(queryBookName.isEmpty()){
            List<BooksEntity> bookList = bookService.queryAllBook();
            model.addAttribute("bookList",bookList);
            return "/allBook";
        }
        List<BooksEntity> bookList = bookService.queryBookByName(queryBookName);
        if(bookList.isEmpty()){
            model.addAttribute("error","查不到");
        }else{
            model.addAttribute("bookList",bookList);
        }
        return "/allBook";
    }

增加查询未找到的显示及查询输入框

<form class="form-inline" action="${pageContext.request.contextPath}/book/queryBook" method="post" style="float: right">
        <span style="color: red; font-weight: bold">${error}</span>
    <input type="text" name="queryBookName" class="form-control" placeholder="输入要查询的书名">
    <input type="submit" value="查询" class="btn btn-primary">
</form>

增加显示所有书按钮

<a class="btn btn-primary" href="${pageContext.request.contextPath}/book/allBook">所有的书</a>