整合Mybatis和mysql

pom.xml加入依赖

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<!-- 整合mybatis -->
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>1.3.2</version>
</dependency>
<!-- mysql -->
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

修改application.yml

我们把application.properties文件改成application.yml（个人觉得yml可读性更好），加入以下配置：

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spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.tt.study.demo.entity

mapper-locations表示mybatis的mapper文件的位置，type-aliases-package表示mapper对应的实体类的包。

配置mybatis-generator-maven-plugin

pom.xml添加以下配置：

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<plugin>
	<groupId>org.mybatis.generator</groupId>
	<artifactId>mybatis-generator-maven-plugin</artifactId>
	<version>1.3.5</version>
	<dependencies>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.44</version>
		</dependency>
	</dependencies>
	<configuration>
		<verbose>true</verbose>
		<overwrite>true</overwrite>
	</configuration>
</plugin>

resources下添加generatorConfig.xml文件，输入下面内容：

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<?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>

    <context id="Mysql" targetRuntime="MyBatis3">

        <commentGenerator>
            <property name="suppressAllComments" value="true" />
        </commentGenerator>

        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/demo?useUnicode=true"
                        userId="root"
                        password="root">
        </jdbcConnection>

        <javaTypeResolver >
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <javaModelGenerator targetPackage="com.tt.study.demo.entity" targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="false" />
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="mapper"  targetProject="src/main/resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <javaClientGenerator type="XMLMAPPER" targetPackage="com.tt.study.demo.mapper"  targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <table schema="demo" tableName="user" domainObjectName="User" >
            <generatedKey column="id" sqlStatement="MySql" identity="true"/>
        </table>

    </context>
</generatorConfiguration>

具体每行配置的意思可以上MyBatis Generator看一下。

配置完后，我们可以在IDEA的maven插件面板看到项目的Plugins下多了一个mybatis-generator，双击mybatis-generator:generate可以运行generator。

jiegou4

测试一下

数据库新建一个user表：

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CREATE TABLE user (
	id bigint PRIMARY KEY AUTO_INCREMENT,
	username varchar(20) NOT NULL DEFAULT '' COMMENT '用户名',
	password varchar(128) NOT NULL DEFAULT '' COMMENT '密码',
	CONSTRAINT user_username_uindex UNIQUE user_username_uindex (username)
) ENGINE = InnoDB COMMENT '用户表';

双击maven插件面板的mybatis-generator:generate运行generator。我们可以看到console输入下面相关信息：

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[INFO] Introspecting table demo.user
[INFO] Generating Example class for table user
[INFO] Generating Record class for table user
[INFO] Generating Mapper Interface for table user
[INFO] Generating SQL Map for table user
[INFO] Saving file UserMapper.xml
[INFO] Saving file UserExample.java
[INFO] Saving file User.java
[INFO] Saving file UserMapper.java

再看我们的项目结构：

jiegou5

已经自动生成了实体类、mapper.xml、mapper.java和一个Example文件，关于这个Example可以自行上网查询一下，可以无需编写sql进行一些简单CRUD操作。

对了，我们看到DemoApplication下多了一个注解@MapperScan("com.tt.study.demo.mapper")，这是声明扫描Mybatis的mapper类，没有这个注解，Spring无法注入mapper类。

接下来在service包下添加一个UserService：

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@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public RespInfo<String> addUser(User user) {
        int count = userMapper.insert(user);
        if (count == 1) {
            return RespInfo.success("添加成功");
        }
        return RespInfo.error("添加失败");
    }
}

HomeController下添加下面代码：

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@Autowired
private UserService userService;

@RequestMapping("/addUser")
@ResponseBody
public Object addUser(User user) {
    return userService.addUser(user);
}

好了，接下来我们页面请求一下：

yemian5

ok，再看下数据库，是不是已经插入了一条新的数据。

pom.xml：

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<?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>

	<groupId>com.tt.study</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>demo</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<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-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<version>1.16.18</version>
		</dependency>
		<!-- 整合mybatis -->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.2</version>
		</dependency>
		<!-- mysql -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</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>
			<plugin>
				<groupId>org.mybatis.generator</groupId>
				<artifactId>mybatis-generator-maven-plugin</artifactId>
				<version>1.3.5</version>
				<dependencies>
					<dependency>
						<groupId>mysql</groupId>
						<artifactId>mysql-connector-java</artifactId>
						<version>5.1.44</version>
					</dependency>
				</dependencies>
				<configuration>
					<verbose>true</verbose>
					<overwrite>true</overwrite>
				</configuration>
			</plugin>
		</plugins>
	</build>

</project>