SSM---无脑整合

一. 创建一个Maven项目

二. 导入依赖

<properties>
  <spring.version>5.2.12.RELEASE</spring.version>
  <slf4j.version>1.6.6</slf4j.version>
  <log4j.version>1.2.12</log4j.version>
  <mysql.version>5.1.6</mysql.version>
  <mybatis.version>3.5.0</mybatis.version>
</properties>

<dependencies>
  <!-- spring -->
  <dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.6.8</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-orm</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>${spring.version}</version>
  </dependency>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
  </dependency>
  <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>${mysql.version}</version>
  </dependency>
  <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
  </dependency>
  <dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>jsp-api</artifactId>
    <version>2.0</version>
    <scope>provided</scope>
  </dependency>
  <dependency>
    <groupId>jstl</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
  </dependency>
  <!-- log start -->
  <dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>${log4j.version}</version>
  </dependency>
  <dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>${slf4j.version}</version>
  </dependency>
  <dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>${slf4j.version}</version>
  </dependency>
  <!-- log end -->
  <dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>${mybatis.version}</version>
  </dependency>
  <dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.6</version>
  </dependency>
  <dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5.2</version>
    <scope>compile</scope>
  </dependency>
  <dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.9</version>
  </dependency>
  <!-- lomlok-->
  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.12</version>
    <scope>provided</scope>
  </dependency>
  <dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>RELEASE</version>
    <scope>compile</scope>
  </dependency>
</dependencies>

三. 创建如图所示的目录结构及对应文件

四. 各配置文件内容展示

4.1 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:tx="http://www.springframework.org/schema/tx"
       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/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    <context:component-scan base-package="com.ljy"/>

    <!-- 开启注解扫描，管理service和dao -->
    <context:component-scan base-package="com.ljy.mapper">
    </context:component-scan>
    <context:component-scan base-package="com.ljy.service">
    </context:component-scan>
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!-- 配置连接池 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="user" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean>
    <!-- 把交给IOC管理 SqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- 扫描mapper接口 -->
    <bean id="mapperScanner" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.ljy.mapper"/>
    </bean>

    <!-- 配置Spring的声明式事务管理 -->
    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

4.2 jdbc.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/lvjianyou?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=false
jdbc.username=root
jdbc.password=root

4.3 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>

    <typeAliases>
        <package name="com.ljy.pojo"/>
    </typeAliases>
    <mappers>
        <package name="com.ljy.mapper"/>
    </mappers>
</configuration>

4.4 springmvc.xml

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

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd ">
    <!-- 扫描controller的注解，别的不扫描 -->
    <context:component-scan base-package="com.ljy.controller">
    </context:component-scan>
    <!-- 配置视图解析器 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- JSP文件所在的目录 -->
        <property name="prefix" value="/WEB-INF/" />
        <!-- 文件的后缀名 -->
        <property name="suffix" value=".jsp" />
    </bean>
    <!-- 设置静态资源不过滤 -->
    <mvc:resources location="/css/" mapping="/css/**" />
    <mvc:resources location="/img/" mapping="/img/**" />
    <mvc:resources location="/js/" mapping="/js/**" />
    <mvc:resources location="/static/" mapping="/static/**" />
    <!-- 开启对SpringMVC注解的支持 -->
    <mvc:annotation-driven />
</beans>

4.5 web.xml

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

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <!-- 配置加载类路径的配置文件 -->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
  <!-- 配置监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.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>
  <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>
</web-app>

五 测试前说明

配置文件和依赖，我们现在都已经完成了，下一步肯定是要把代码写出来，然后我们ssm三层一起跑一下，看看环境有没有搭建成功，所以说我们可以自己创建一个数据库表，然后对应写出controller，service，mapper层，然后进行测试哦！

如下
先来数据库表

create table user(
id int(5) primary key,
name varchar(20),
age int(2),
description varchar(100)

) default charset=utf8;

insert into user values(1,'吕建友',21,'还不错哟');
insert into user values(2,'小龙女',12,'还不错哟');
insert into user values(3,'奥特曼',56,'还不错哟');
insert into user values(4,'迪迦',42,'还不错哟');
insert into user values(5,'成龙',66,'还不错哟');

实体类User

@Data
public class User implements Serializable {
  private int id;
  private String name;
  private int age;
  private String description;

}

mapper

@Repository
public interface UserMapper {

  @Select("select * from user")
  List<User> findAll();
}

controller

@RestController
@RequestMapping("/user")
public class UserController {

  @Autowired
  private UserMapper userMapper;

  @GetMapping("/findAll")
  public String getAll(){
    List<User> all = userMapper.findAll();
    return all.get(0).getName();
  }
}

service? 就先不写了，能够依赖注入就代表spring的环境没问题！

来个jsp试试

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<html>
<body>
<h2>Hello World!</h2>
<a href="/test/test1">点击我进行测试！</a>
<a href="/user/findAll">点击我进行查询！</a>
</body>
</html>

配置好我们的Tom猫

好，接下来就直接运行！！冲冲冲

六.运行结果

点击进去，查询成功！

至此，收工~

七. 总结

7.1 版本问题

如果mybatis和spring版本不匹配，或者因为其他jar包版本不匹配的话，很可能会出现各种各样问题报错，这个要多注意。

7.2 mapper文件和xml无法绑定成功

这是因为maven默认不编译xml文件所导致的， 在pom.xml中添加如下配置，让maven开启编译xml文件

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

7.3 applicationContext.xml中无法读取jdbc.properties的数据

before：

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

after：

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

7.4 如果运行过程中报错

Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!

把jdbc.properties中的dirver改一下

jdbc.driver=com.mysql.jdbc.Driver