以前整合了Spring+SpringMVC+Mybatis,今天用SpringBoot整合了Mybatis,发现这个比之前的SSM的整合方便的太多,省去大量的配置文件,也许是我还没用到很深入吧,话不多说,直接进入正题。
1、创建一个SpringBoot项目:
2、下一步:
3、然后加入一些需要的依赖,这里用的SpringBoot2:
4、创建成功之后查看一下pom里面的配置:
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.thr</groupId>
<artifactId>spring-boot-mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-mybatis</name>
<description>Demo project for Spring Boot</description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- mybatis generator 自动生成代码插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
</plugin>
</plugins>
</build>
</project>
注意:pom文件里面的 mybatis generator 自动生成代码插件 是自己要加进去的:
<!-- mybatis generator 自动生成代码插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
</plugin>
5、配置application.properties文件,一般不使用这个,推荐使用application.yml,将properties改成yml就可以了,但是这里方便就不该了。
server.port=8080
#mapper文件的位置
mybatis.mapper-locations=classpath:mapper/*.xml
#对应实体类的位置
type-aliases-package=com.thr.entity
#配置数据源
spring.datasource.username=root
spring.datasource.password=root
#使用druid数据源
#type: com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/db_user?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
6、然后创建数据库db_user:
CREATE TABLE `t_user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(64) DEFAULT NULL,
`password` varchar(64) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of t_user
-- ----------------------------
INSERT INTO `t_user` VALUES ('1', 'admin', '123');
7、使用Mybatis的Generator自动生成类,在项目的resources下添加generatorConfig.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
<classPathEntry location="E:\mysql-connector-java-5.1.28-bin.jar"/>
<context id="testTables" targetRuntime="MyBatis3">
<commentGenerator>
<!-- 是否去除自动生成的注释 true:是 : false:否 -->
<property name="suppressAllComments" value="true" />
</commentGenerator>
<!--数据库连接的信息:驱动类、连接地址、用户名、密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/db_user"
userId="root"
password="root">
</jdbcConnection>
<!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver"
connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:user"
userId="yycg"
password="yycg">
</jdbcConnection> -->
<!-- 默认false,把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer,为 true时把JDBC DECIMAL 和
NUMERIC 类型解析为java.math.BigDecimal -->
<javaTypeResolver>
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- targetProject:生成PO类的位置 -->
<javaModelGenerator targetPackage="com.thr.entity"
targetProject=".\src\main\java">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
<!-- 从数据库返回的值被清理前后的空格 -->
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- targetProject:mapper映射文件生成的位置 -->
<sqlMapGenerator targetPackage="mapper"
targetProject=".\src\main\resources">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
</sqlMapGenerator>
<!-- targetPackage:mapper接口生成的位置 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="com.thr.dao"
targetProject=".\src\main\java">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
</javaClientGenerator>
<!-- 指定数据库表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
<table tableName="t_user"
domainObjectName="User"
enableCountByExample="false"
enableUpdateByExample="false"
enableDeleteByExample="false"
enableSelectByExample="false"
selectByExampleQueryId="false">
</table>
<!-- 有些表的字段需要指定java类型
<table schema="" tableName="">
<columnOverride column="" javaType="" />
</table> -->
</context>
</generatorConfiguration>
8、然后在IDEA的右边找到Maven Projects,找到之前的插件,双击:注意!!!同一张表一定不要运行多次,因为mapper的映射文件中会生成多次的代码,切记不要多次运行!!!
运行完成后就可以看到:
9、打开类SpringbootMybatisDemoApplication.java,这个是springboot的启动类。我们需要添加点东西:
注意:@MapperScan("com.thr.dao")这个注解非常的关键,这个对应了项目中mapper(dao)所对应的包路径,很多同学就是这里忘了加导致异常的。如果不在启动类这里加,也可以在Mapper类上面添加注解@Mapper
,建议使用上面那种,不然每个mapper加个注解也挺麻烦的。
package com.thr;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.thr.dao")
public class SpringBootMybatisApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootMybatisApplication.class, args);
}
}
10、然后就是Controller,Service层了:
UserController类:
@RestController
public class UserController {
@Autowired
private UserService userService;
@GetMapping(value = "/user")
public Object User(){
return userService.findAllUser();
}
}
UserMapper下要加一个方法List<User> findAllUser():
public interface UserMapper {
int deleteByPrimaryKey(Integer id);
int insert(User record);
int insertSelective(User record);
User selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(User record);
int updateByPrimaryKey(User record);
List<User> findAllUser();
}
所以相应的Mapper.xml也要添加一条SQL语句;
<select id="findAllUser" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
select
<include refid="Base_Column_List" />
from t_user
</select>
UserService接口:
/**
* @author
* @name
*/
public interface UserService {
List<User> findAllUser();
}
UserServiceImpl实现类:
/**
* @author
* @name
*/
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserMapper userMapper;
@Override
public List<User> findAllUser() {
return userMapper.findAllUser();
}
}
总体目录结构如下:
11、运行启动类,然后访问http://localhost:8080/user:
成功访问,SpringBoot成功整合Mybatis。
如果访问不了,那就在pom下面的build中添加下面的代码:这是IDEA的原因,有时候有些文件没有编译到target下,配置下面这个后就可以了。
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.*</include>
</includes>
</resource>
<resource>
<directory>src/main/webapp</directory>
<targetPath>META-INF/resources</targetPath>
<includes>
<include>**/*.*</include>
</includes>
</resource>
</resources>