SpringBoot之自定义MyBatis-Plus配置

修改原生的YML配置，采取自定义模式，

依赖

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
    <skipTests>true</skipTests>
    <spring-boot.version>2.4.2</spring-boot.version>
</properties>

<dependencies>
    <!-- 数据库 连接 、事务-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <!-- 数据库 mybatis-->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.3.2</version>
    </dependency>
    <!-- 数据库 mysql-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.25</version>
    </dependency>
    <!-- 数据库 sqlite -->
    <dependency>
        <groupId>org.xerial</groupId>
        <artifactId>sqlite-jdbc</artifactId>
        <version>3.27.2.1</version>
    </dependency>
    <!-- 数据库 oracle -->
    <dependency>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc6</artifactId>
        <version>12.1.0.1-atlassian-hosted</version>
    </dependency>
</dependencies>

配置

创建Bean的注入方式，使用 @ConditionalOnMissingClass 注解进行判断bean是否存在，
如不存在则加载当前默认bean，如存在则使用配置bean.

MybatisDataConfig

import lombok.Data;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
import org.springframework.stereotype.Component;

/**
 * author ：demon
 * date ：2022 2022/3/18 15:41
 * desc ：自定义bean
 */
@Data
@Component(value = "mybatisDataConfig")
@ConditionalOnMissingClass(value = "mybatisDataConfig")
public class MybatisDataConfig {

    private String driverClassName;
    private String jdbcUrl;
    private String username;
    private String password;
    
    private String poolName = "DataSource_HikariCP";
    private long connectionTimeoutMs = 30000;
    private long idleTimeoutMs = 300000;
    private long validationTimeoutMs = 5000;
    private long maxLifetimeMs = 1800000;
    private int maxPoolSize = 20;
    private int minIdle = 5;

    private String typeAliasesPackage = "**.database.entity";
    private String locationPattern = "classpath*:/mapper/*Mapper.xml";

}

DataSourceConfig

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.sql.DataSource;

/**
 * author ：demon
 * date ：2021 2021/8/27 13:54
 * desc ：数据库
 */
@Slf4j
@Component
public class DataSourceConfig {

    @Resource(name = "mybatisDataConfig")
    private MybatisDataConfig mybatisDataConfig;

    @Bean(name = "dataSource")
    @Primary
    public DataSource getDataSource() {
        System.out.println("★★★★★配置 dataSource ★★★★★");
        HikariConfig hikariConfig = new HikariConfig();
        hikariConfig.setDriverClassName(mybatisDataConfig.getDriverClassName());
        hikariConfig.setJdbcUrl(mybatisDataConfig.getJdbcUrl());
        hikariConfig.setUsername(mybatisDataConfig.getUsername());
        hikariConfig.setPassword(mybatisDataConfig.getPassword());
        // 自定义连接池名称
        hikariConfig.setPoolName(mybatisDataConfig.getPoolName());
        hikariConfig.setReadOnly(false);
        // 等待连接池分配连接的最大时长（毫秒），超过这个时长还没可用的连接则发生SQLException， 缺省:30秒
        hikariConfig.setConnectionTimeout(mybatisDataConfig.getConnectionTimeoutMs());
        // 一个连接idle状态的最大时长（毫秒），超时则被释放（retired），缺省:10分钟
        hikariConfig.setIdleTimeout(mybatisDataConfig.getIdleTimeoutMs());
        // 验证与数据库连接的有效时间
        hikariConfig.setValidationTimeout(mybatisDataConfig.getValidationTimeoutMs());
        // 建议设置比数据库超时时长少30秒，参考MySQL wait_timeout参数（show variables like '%timeout%';）
        hikariConfig.setMaxLifetime(mybatisDataConfig.getMaxLifetimeMs());
        // 连接池中允许的最大连接数。缺省值：10；推荐的公式：((core_count * 2) + effective_spindle_count)
        hikariConfig.setMaximumPoolSize(mybatisDataConfig.getMaxPoolSize());
        // 连接池中维护的最小空闲连接数
        hikariConfig.setMinimumIdle(mybatisDataConfig.getMinIdle());
        // 从池返回的连接的默认自动提交行为。默认值为true
        hikariConfig.setAutoCommit(true);
        // 如果您的驱动程序支持JDBC4，我们强烈建议您不要设置此属性
        hikariConfig.setConnectionTestQuery("SELECT 1");
        return new HikariDataSource(hikariConfig);
    }

}

MybatisPlusConfig

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.autoconfigure.SpringBootVFS;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.core.MybatisXMLLanguageDriver;
import com.baomidou.mybatisplus.core.config.GlobalConfig;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.session.AutoMappingBehavior;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.type.JdbcType;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.annotation.Resource;
import javax.sql.DataSource;

/**
 * className    MybatisPlusConfig
 * author       demon
 * createTime   2021/5/21 18:15
 * description  mybatis-plus 配置
 */
@Slf4j
@Component
@EnableTransactionManagement
public class MybatisPlusConfig {

    @Resource(name = "mybatisDataConfig")
    private MybatisDataConfig mybatisDataConfig;

    @Resource
    private DataSource dataSource;

    /**
     * 分页插件
     * paginationInterceptor.setLimit(你的最大单页限制数量，默认 500 条，小于 0 如 -1 不受限制);
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求  默认false
        paginationInterceptor.setOverflow(true);
        // 设置最大单页限制数量，默认 500 条，-1 不受限制
        paginationInterceptor.setLimit(-1);
        // 开启 count 的 join 优化,只针对部分 left join
        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }

    /**
     * 将yml配置代码化
     */
    @Bean
    @Primary
    public MybatisSqlSessionFactoryBean mybatisSqlSessionFactoryBean() throws Exception {
        //一定要使用 MybatisSqlSessionFactoryBean否则Statement not bound错误
        System.out.println("★★★★★配置 MybatisSqlSessionFactoryBean ★★★★★");
        MybatisSqlSessionFactoryBean mybatisPlus = new MybatisSqlSessionFactoryBean();
        //加载数据源  此处配置为关键配置，如果没有将 dataSource 作为数据源则不能实现切换
        mybatisPlus.setDataSource(dataSource);
        mybatisPlus.setVfs(SpringBootVFS.class);
        // 配置 configuration
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        // 映射器缓存
        configuration.setCacheEnabled(false);
        // 查询时，关闭关联对象即时加载以提高性能
        configuration.setLazyLoadingEnabled(false);
        // 不允许使用自定义的主键值(比如由程序生成的UUID 32位编码作为键值), 数据表的PK生成策略将被覆盖
        configuration.setUseGeneratedKeys(false);
        // 对于批量更新操作缓存SQL以提高性能 SIMPLE, REUSE, BATCH
        configuration.setDefaultExecutorType(ExecutorType.REUSE);
        // 对于未知的SQL查询，允许返回不同的结果集以达到通用的效果
        configuration.setMultipleResultSetsEnabled(true);
        // 允许使用列标签代替列名
        configuration.setUseColumnLabel(true);
        // 解决mybatis空字段null字段不返回
        configuration.setCallSettersOnNulls(true);
        // 给予被嵌套的resultMap以字段-属性的映射支持 NONE, FULL,PARTIAL
        configuration.setAutoMappingBehavior(AutoMappingBehavior.PARTIAL);
        // 日志
        configuration.setLogImpl(org.apache.ibatis.logging.stdout.StdOutImpl.class);
        mybatisPlus.setConfiguration(configuration);
        // 添加分页功能
        mybatisPlus.setPlugins(paginationInterceptor());
        //加载 mybatis-plus 全局配置
        GlobalConfig globalConfig = new GlobalConfig();
        GlobalConfig.DbConfig dbConfig = new GlobalConfig.DbConfig();
        // 默认为自增
        dbConfig.setIdType(IdType.AUTO);
        // 全局的表前缀策略配置
        globalConfig.setDbConfig(dbConfig);
        mybatisPlus.setGlobalConfig(globalConfig);
        //指定 pojo 目录 ，扫描Model
        mybatisPlus.setTypeAliasesPackage(mybatisDataConfig.getTypeAliasesPackage());
        // Mapper包路径， 扫描映射文件
        mybatisPlus.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mybatisDataConfig.getLocationPattern()));
        return mybatisPlus;
    }

}