java篇-非spring项目使用mybatis-plus

写在前面

这里讲解如何在非spring项目下使用mybatis-plus，并集成mybatis-plus的特性，实现数据库的增删改查

初始化项目

项目由maven构建,并且使用junit做项目测试实验，pom配置如下

<?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.lhstack.mybatis</groupId>
    <artifactId>mybatis-plus-test</artifactId>
    <version>0.0.1</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <mybatis-plus.version>3.4.3</mybatis-plus.version>
        <hikaricp.version>4.0.3</hikaricp.version>
        <mysql.version>8.0.23</mysql.version>
        <junit.version>4.13</junit.version>
        <slf4j.version>1.7.31</slf4j.version>
        <logback.version>1.2.3</logback.version>
    </properties>


    <dependencies>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>${logback.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus-extension -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-extension</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.zaxxer/HikariCP -->
        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>${hikaricp.version}</version>
        </dependency>
    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**</include>
                </includes>
            </resource>
        </resources>
        <testResources>
            <testResource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**</include>
                </includes>
            </testResource>
        </testResources>
    </build>

</project>

项目最终结构如下

使用junit初始化数据源

编写测试代码

	@Test
    public void testDataSource() throws Exception {
   
        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl("jdbc:mysql://192.168.101.150:3306/cms?allowPublicKeyRetrieval=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8&useUnicode=true");
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUsername("root");
        dataSource.setPassword("123456");
        dataSource.setIdleTimeout(60000);
        dataSource.setAutoCommit(true);
        dataSource.setMaximumPoolSize(5);
        dataSource.setMinimumIdle(1);
        dataSource.setMaxLifetime(60000 * 10);
        dataSource.setConnectionTestQuery("SELECT 1");
        Connection connection = dataSource.getConnection();
        PreparedStatement preparedStatement = connection.prepareStatement("show table status");
        ResultSet resultSet = preparedStatement.executeQuery();
        while(resultSet.next()){
   
            ResultSetMetaData metaData = resultSet.getMetaData();
            int columnCount = metaData.getColumnCount();
            for (int i = 1; i <= columnCount; i++) {
   
                String name = metaData.getColumnLabel(i);
                String field = resultSet.getString(i);
                System.out.printf("%s:%s\t",name,field);
            }
            System.out.println();
        }
    }

运行效果如下

构建mybatis-plus里面的SqlSessionFactoryBuilder对象

	@Before
    public void before() throws IOException {
   
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        //这是mybatis-plus的配置对象，对mybatis的Configuration进行增强
        MybatisConfiguration configuration = new MybatisConfiguration();
        //这是初始化配置，后面会添加这部分代码
        initConfiguration(configuration);
        //这是初始化连接器，如mybatis-plus的分页插件
        configuration.addInterceptor(initInterceptor());
        //配置日志实现
        configuration.setLogImpl(Slf4jImpl.class);
        //扫描mapper接口所在包
        configuration.addMappers("com.lhstack.mybatis.mapper");
        //构建mybatis-plus需要的globalconfig
        GlobalConfig globalConfig = GlobalConfigUtils.getGlobalConfig(configuration);
        //此参数会自动生成实现baseMapper的基础方法映射
        globalConfig.setSqlInjector(new DefaultSqlInjector());
        //设置id生成器
        globalConfig.setIdentifierGenerator(new DefaultIdentifierGenerator());
        //设置超类mapper
        globalConfig.setSuperMapperClass(BaseMapper.class);
        //设置数据源
        Environment environment = new Environment("1", new JdbcTransactionFactory(), initDataSource());
        configuration.setEnvironment(environment);
        this.registryMapperXml(configuration, "mapper");
        //构建sqlSessionFactory
        SqlSessionFactory sqlSessionFactory = builder.build(configuration);
        //创建session
        this.session = sqlSessionFactory.openSession();
    }
    /**
     * 初始化配置
     *
     * @param configuration
     */
    private void initConfiguration(MybatisConfiguration configuration) {
   
    	//开启驼峰大小写转换
        configuration.setMapUnderscoreToCamelCase(true);