IDEA SpringMVC集成mybatis教程

秒速五厘米 2022-06-11 08:40 317阅读 0赞

目前Spring集成mybatis的教程，都比较混杂，很难找到零基础入门文章，而且很多教程实例涉及的内容很多，工程配置复杂，很难让新手跟着做完，可以运行的项目。也是 因为时间紧，没有去mybatis官网看文档，一天多时间找的中文的博客，发现部分博客实例都比较老，spring和mybatis的版本是一个问题，还有就是开发工具的不一致，MyEclipse、Eclipse EE、[IntelliJ IDEA][IntelliJ_IDEA]什么样的都有，这里建议在学习这些框架时首先确定一下开发工具，再找相对应的教程，会让你省去很多时间。

使用mybatis，最简单的方式就是spring-boot-mybatis，创建Spring boot工程，省去mybatis配置文件，自行参阅：[http://blog.csdn.net/ljheee/article/details/76599363][http_blog.csdn.net_ljheee_article_details_76599363]

Mybatis最大的特点是：只需要写好 针对实体类映射数据库表的接口，不需要写接口的实现，mybatis动态完成接口的实现。

Mybatis完成java实体类和数据库表的ORM映射，主要有两种方式，一种是基于注解的，上面的Spring boot集成mybatis就是这种方式；另外一种是基于XXXMaper.xml，用xml文件装配sql，mybatis动态实现接口的Impl，自动加载到Spring IoC容器，controller在需要时即可Autowired，本教程就是用第二种方式，实现最简单的User实体类与数据库表的映射，完成增删改查。

两种方式共同点：sql语句需要程序员来写，对sql书写有一定的要求。但是同时，也发挥了sql灵活性的价值。第一种sql写在注解中，对于简单操作很容易实现，第二种xml中直接写sql语句，更能胜任复杂的sql查询等操作。

注意事项：工程的配置文件xml，文件最上面都是有dtd规范的、以及xml版本信息，在看别人教程的时候，xml配置文件头部的dtd，尽量和教程保持一致。有很对教程没有贴这部分内容，让后者踩了很多坑。

### 本教程工具 ###

IDE为[IntelliJ IDEA][IntelliJ_IDEA] 2017.2

JDK环境为1.8

maven版本为maven3

Mysql版本为5.5.27

Tomcat版本为8.5

### 目标 ###

完成基本的SpringMVC + Spring + MyBatis框架整合(简单实例：完成User实体类的增删改查)

数据库使用mysql

加入c3p0数据库连接池

maven依赖的版本管理

### 一、SSM框架整合配置 ###

1、使用idea的maven创建一个基本的web工程,即**maven-archetype-webapp**

提示：IDEA最好设置阿里镜像，自行参考http://blog.csdn.net/a1b2c3d4123456/article/details/53915056

2、整理项目文件组织结构.

配置目录:

（1）创建main目录下的java目录(用于存放java源代码)

右键点击main目录,接着选中New→Directory,在弹出的对话框中输入java

右键点击java,然后选择Mark Directory As→Sources Root

（2）在resources目录下新建mapper和spring目录

右键点击resources目录,接着选中New→Directory,在弹出的对话框中输入mapper。Spring类似。

![SouthEast][]

3、添加pom.xml依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
      <modelVersion>4.0.0</modelVersion>
      <groupId>com.test</groupId>
      <artifactId>seckill</artifactId>
      <packaging>war</packaging>
      <version>1.0-SNAPSHOT</version>
      <name>seckill Maven Webapp</name>
      <url>http://maven.apache.org</url>
    
    
      <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    
        
        <spring.version>4.3.3.RELEASE</spring.version>
        <jackson.version>2.6.3</jackson.version>
      </properties>
    
    
      <dependencies>
        
        <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>5.1.39</version>
          <scope>runtime</scope>
        </dependency>
        <dependency>
          <groupId>c3p0</groupId>
          <artifactId>c3p0</artifactId>
          <version>0.9.1.1</version>
        </dependency>
    
        
        <dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis</artifactId>
          <version>3.4.1</version>
        </dependency>
        <dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis-spring</artifactId>
          <version>1.3.0</version>
        </dependency>
    
        
        <dependency>
          <groupId>taglibs</groupId>
          <artifactId>standard</artifactId>
          <version>1.1.2</version>
        </dependency>
        <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>jstl</artifactId>
          <version>1.2</version>
        </dependency>
        <dependency>
          <groupId>com.fasterxml.jackson.core</groupId>
          <artifactId>jackson-databind</artifactId>
          <version>2.6.7</version>
        </dependency>
        <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>javax.servlet-api</artifactId>
          <version>3.1.0</version>
        </dependency>
    
        
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</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-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-jdbc</artifactId>
          <version>${spring.version}</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-tx</artifactId>
          <version>${spring.version}</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-web</artifactId>
          <version>${spring.version}</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-webmvc</artifactId>
          <version>${spring.version}</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-test</artifactId>
          <version>${spring.version}</version>
        </dependency>
    
      </dependencies>
      <build>
        <finalName>seckill</finalName>
      </build>
    </project>

4、添加数据库设置jdbc.properties

在resources目录下新建jdbc.properties，配置信息如下：

driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://172.18.81.146:3306/test
    username=lee
    password=lee
    
    idleConnectionTestPeriod=60
    maxIdleTime=240
    acquireIncrement=5
    initialPoolSize=10
    maxPoolSize=30
    minPoolSize=10
    autoCommitOnClose=false
    checkoutTimeout=1000
    acquireRetryAttempts=2

User实体类对应的数据库表：

SET FOREIGN_KEY_CHECKS=0;
    DROP TABLE IF EXISTS `user`;
    CREATE TABLE `user` (
      `id` int(11) NOT NULL AUTO_INCREMENT,
      `appid` varchar(255) DEFAULT NULL,
      `name` varchar(255) DEFAULT NULL,
      `passwd` varchar(255) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

5、添加mybatis全局设置mybatis-config.xml

在resources目录下新建mybatis-config.xml，配置信息如下：

<?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>
            
            <setting name="useGeneratedKeys" value="true" />
    
            <setting name="useColumnLabel" value="true" />
    
            
            <setting name="mapUnderscoreToCamelCase" value="true" />
        </settings>
    
    </configuration>

6、添加数据库设置spring-dao.xml

在 resources/spring下新建spring-dao.xml，配置信息如下：

7、修改webapp\\WEB-INF\\web.xml，信息如下：

<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_3_1.xsd"
             version="3.1"
             metadata-complete="true">
    
      
      <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:spring/spring-dao.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>
    
      <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>
        <init-param>
          <param-name>forceEncoding</param-name>
          <param-value>true</param-value>
        </init-param>
      </filter>
    
      <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <servlet-name>SpringMVC</servlet-name>
      </filter-mapping>
    </web-app>

### 二、实体映射 ###

第一部分，完成了骨架工程和框架的配置。下面增加实体类、操作实体类的接口，完成增删改查。

1、创建User.java

右键java，创建一个package，例如com.test。右键com.test创建三个包entity、dao、controller。

分别在entity、dao、controller创建User.java、UserDao.java、UserController.java。

User.java

package com.test.entity;
    
    /**
     * 实体类：属性对应数据库表的字段
     */
    public class User {
    
        private Integer id;
        private String name;
        private String passwd;
        private String appid;
    
        public User(Integer id , String name, String passwd, String appid) {
            this.id = id;
            this.name = name;
            this.passwd = passwd;
            this.appid = appid;
        }
    
    
        public User(String name, String passwd, String appid) {
            this.name = name;
            this.passwd = passwd;
            this.appid = appid;
        }
        public User(String name, String passwd) {
            this.name = name;
            this.passwd = passwd;
        }
    
        public User() {
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getPasswd() {
            return passwd;
        }
    
        public void setPasswd(String passwd) {
            this.passwd = passwd;
        }
    
        public String getAppid() {
            return appid;
        }
    
        public void setAppid(String appid) {
            this.appid = appid;
        }
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", passwd='" + passwd + '\'' +
                    ", appid='" + appid + '\'' +
                    '}';
        }
    }

UserDao.java

package com.test.dao;
    
    import com.test.entity.User;
    
    /**
     * DAO接口,mybatis动态完成Impl
     */
    public interface UserDao {
    
        Integer addUser(User u);
    
        User findByAppid(String appid);
    
        User findById(Integer id);
    
        Integer deleteById(Integer id);
    }

2、创建Controller

UserController.java

package com.test.controller;
    
    import com.test.dao.UserDao;
    import com.test.entity.User;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping(value = "/test")
    public class UserController {
    
        @Autowired(required = false)
        private UserDao userDao;
    
        @RequestMapping(value ="/phone", method = RequestMethod.GET)
        public User test(){
            return userDao.findByAppid("10524782571");
        }
    
        //-http://localhost:8080/test/add?name=abc&passwd=123&appid=95955542783
        @RequestMapping(value = "/add", method = RequestMethod.GET)
        public User save(@RequestParam("name") String name,
                         @RequestParam(value = "passwd",defaultValue = "0") String passwd,
                         @RequestParam(value = "appid",defaultValue = "0") String appid) {
            User user = new User(name,passwd,appid);
            userDao.addUser(user);
            return userDao.findById(user.getId());
        }
    
    
    
        @RequestMapping(value = "/delete", method = RequestMethod.GET)
        public void delete(@RequestParam("id") Integer id) {
            userDao.deleteById(id);
        }
    
    }

最后的工程结构如下图：

![SouthEast 1][]

测试：

通过浏览器输入

http://localhost:8080/test/add?name=abc&passwd=123&appid=95955542783

插入数据库，返回对象的json格式。

源码下载：[http://download.csdn.net/detail/ljheee/9920061][http_download.csdn.net_detail_ljheee_9920061]

===2018-7-18更新：没有下载积分的，可以[https://github.com/ljheee/my-simple-ssm][https_github.com_ljheee_my-simple-ssm]

网上Spring集成mybatis的文章很杂乱，这两篇推荐一下：

[http://www.mybatis.org/spring/zh/getting-started.html][http_www.mybatis.org_spring_zh_getting-started.html]

[http://www.jianshu.com/p/5124eef40bf0][http_www.jianshu.com_p_5124eef40bf0]

[spring mybatis 整合后mapper接口注入失败问题][spring_mybatis_mapper]

[http://blog.csdn.net/u012012240/article/details/51252560][spring_mybatis_mapper]

**MyBatis获取数据库自生成的主键Id详解**

http://www.jb51.net/article/112942.htm

[IntelliJ_IDEA]: http://www.baidu.com/link?url=CpXNb7QUvqqxzesT0eotVfCkILXMLl63-Q0UbHprAq7waJHvwX4tACntn68K4FZS
[http_blog.csdn.net_ljheee_article_details_76599363]: http://blog.csdn.net/ljheee/article/details/76599363
[SouthEast]: /images/20220611/96c09bf4f56040919bce4f334eca0ee7.png
[SouthEast 1]: /images/20220611/7782bed61d7f491fb33138b3f468640e.png
[http_download.csdn.net_detail_ljheee_9920061]: http://download.csdn.net/detail/ljheee/9920061
[https_github.com_ljheee_my-simple-ssm]: https://github.com/ljheee/my-simple-ssm
[http_www.mybatis.org_spring_zh_getting-started.html]: http://www.mybatis.org/spring/zh/getting-started.html
[http_www.jianshu.com_p_5124eef40bf0]: http://www.jianshu.com/p/5124eef40bf0
[spring_mybatis_mapper]: http://blog.csdn.net/u012012240/article/details/51252560