SpringBoot整合Mybatis實(shí)現(xiàn)多數(shù)據(jù)源配置與跨數(shù)據(jù)源事務(wù)實(shí)例

更新時(shí)間：2022年11月28日 14:37:22 作者：喜羊羊sk

開發(fā)中經(jīng)常有這樣的需要: 讀寫分離。微服務(wù)環(huán)境下可以實(shí)現(xiàn)一個(gè)服務(wù)讀取一個(gè)數(shù)據(jù)庫(kù)，另一個(gè)服務(wù)寫庫(kù)。但是在實(shí)際應(yīng)用中有時(shí)也需要在一個(gè)服務(wù)中讀寫不同的數(shù)據(jù)庫(kù)?？梢栽谝粋€(gè)SpringBoot單體項(xiàng)目中配置多個(gè)數(shù)據(jù)源解決讀寫庫(kù)分離

Pom依賴

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.2.RELEASE</version>
    <relativePath/>
</parent>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.2.14</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.2.2</version>
    </dependency>
    <!--   分頁(yè)插件     -->
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper-spring-boot-starter</artifactId>
        <version>1.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
</dependencies>

application.yml

# 數(shù)據(jù)源
spring:
datasource:
# master主數(shù)據(jù)源配置
master:
driverClassName: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds1?characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: root
# cluster從數(shù)據(jù)源配置
cluster:
driverClassName: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds2?characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: root
#pagehelper分頁(yè)插件配置
pagehelper:
master:
helper-dialect: mysql #設(shè)置數(shù)據(jù)庫(kù)類型
reasonable: true #開啟合理化：頁(yè)碼<=0 查詢第一頁(yè)，頁(yè)碼>=總頁(yè)數(shù)查詢最后一頁(yè)
support-methods-arguments: true #支持通過 Mapper 接口參數(shù)來傳遞分頁(yè)參數(shù)
params: count=countsql

多數(shù)據(jù)源配置

Java代碼方式創(chuàng)建主從數(shù)據(jù)源配置。使用@Primary: 用于指定bean的注入優(yōu)先級(jí)。被@Primary修飾的bean對(duì)象優(yōu)先注入

MasterDataSourceConfig

/**
 * @ClassName: MasterDataSourceConfig
 * @Description: mysql主庫(kù)配置類
 */
@Configuration
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE,sqlSessionTemplateRef = "masterSqlSessionTemplate")
public class MasterDataSourceConfig {
    /**
     * 設(shè)置掃描包的路徑
     */
    public static final String PACKAGE = "cn.zysheep.dao.master";
    /**
     * Mapper配置文件路徑
     */
    public static final String MAPPER_LOCATION = "classpath*:mapper/master/*.xml";
    /**
     * 實(shí)體別名
     */
    public static final String ENTITY_ALIASES = "cn.zysheep.entity";
    @Value("${spring.datasource.master.driverClassName}")
    private String driverClassName;
    @Value("${spring.datasource.master.url}")
    private String url;
    @Value("${spring.datasource.master.username}")
    private String user;
    @Value("${spring.datasource.master.password}")
    private String password;
    @Value("${pagehelper.master.helper-dialect}")
    private String helperDialect;
    @Value("${pagehelper.master.reasonable}")
    private String reasonable;
    /**
     * 創(chuàng)建數(shù)據(jù)源
     * @return DataSource
     * @Primary: 用于指定bean的注入優(yōu)先級(jí)。被@Primary修飾的bean對(duì)象優(yōu)先注入
     */
    @Bean(name = "masterDataSource")
    @Primary
    public DataSource masterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }
    /**
     * 創(chuàng)建工廠
     *@param dataSource
     *@throws Exception
     *@return SqlSessionFactory
     */
    @Bean(name = "masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(MAPPER_LOCATION));
        sessionFactory.setTypeAliasesPackage(ENTITY_ALIASES);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        // 字段值為空也可以插入
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setCallSettersOnNulls(true);
        // mybatis log
        configuration.setLogImpl(StdOutImpl.class);
        sessionFactory.setConfiguration(configuration);
        PageInterceptor pageInterceptor = new PageInterceptor();
        // 分頁(yè)配置
        Properties p = new Properties();
        p.setProperty("helperDialect", helperDialect);
        p.setProperty("reasonable", reasonable);
        pageInterceptor.setProperties(p);
        sessionFactory.setPlugins(pageInterceptor);
        return sessionFactory.getObject();
    }
    /**
     * 創(chuàng)建事務(wù)
     *@param dataSource
     *@return DataSourceTransactionManager
     */
    @Bean(name = "masterTransactionManager")
    @Primary
    public DataSourceTransactionManager masterDataSourceTransactionManager(@Qualifier("masterDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
    /**
     * 創(chuàng)建模板
     *@param sqlSessionFactory
     *@return SqlSessionTemplate
     */
    @Bean(name = "masterSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate masterSqlSessionTemplate(@Qualifier("masterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

ClusterDataSourceConfig

/**
 * @ClassName: DataSourceConfig
 * @Description: mysql從庫(kù)配置類
 */
@Configuration
@MapperScan(basePackages = ClusterDataSourceConfig.PACKAGE,sqlSessionTemplateRef = "clusterSqlSessionTemplate")
public class ClusterDataSourceConfig {
    /**
     * 設(shè)置掃描包的路徑
     */
    public static final String PACKAGE = "cn.zysheep.dao.cluster";
    /**
     * Mapper配置文件路徑
     */
    public static final String MAPPER_LOCATION = "classpath*:mapper/cluster/*.xml";
    /**
     * 實(shí)體別名
     */
    public static final String ENTITY_ALIASES = "cn.zysheep.entity";
    @Value("${spring.datasource.cluster.driverClassName}")
    private String driverClassName;
    @Value("${spring.datasource.cluster.url}")
    private String url;
    @Value("${spring.datasource.cluster.username}")
    private String user;
    @Value("${spring.datasource.cluster.password}")
    private String password;
    @Value("${pagehelper.master.helper-dialect}")
    private String helperDialect;
    @Value("${pagehelper.master.reasonable}")
    private String reasonable;
    /**
     * 創(chuàng)建數(shù)據(jù)源
     *@return DataSource
     */
    @Bean(name = "clusterDataSource")
    public DataSource masterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }
    /**
     * 創(chuàng)建工廠
     *@param dataSource
     *@throws Exception
     *@return SqlSessionFactory
     */
    @Bean(name = "clusterSqlSessionFactory")
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("clusterDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(MAPPER_LOCATION));
        sessionFactory.setTypeAliasesPackage(ENTITY_ALIASES);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        // 字段值為空也可以插入
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setCallSettersOnNulls(true);
        // mybatis log
        configuration.setLogImpl(StdOutImpl.class);
        sessionFactory.setConfiguration(configuration);
        PageInterceptor pageInterceptor = new PageInterceptor();
        // 分頁(yè)配置
        Properties p = new Properties();
        p.setProperty("helperDialect", helperDialect);
        p.setProperty("reasonable", reasonable);
        pageInterceptor.setProperties(p);
        sessionFactory.setPlugins(pageInterceptor);
        return sessionFactory.getObject();
    }
    /**
     * 創(chuàng)建事務(wù)管理器
     *@param dataSource
     *@return DataSourceTransactionManager
     */
    @Bean(name = "clusterTransactionManager")
    public DataSourceTransactionManager masterDataSourceTransactionManager(@Qualifier("clusterDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
    /**
     * 創(chuàng)建模板
     *@param sqlSessionFactory
     *@return SqlSessionTemplate
     */
    @Bean(name = "clusterSqlSessionTemplate")
    public SqlSessionTemplate masterSqlSessionTemplate(@Qualifier("clusterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

啟動(dòng)類

啟動(dòng)類添加@EnableTransactionManagement注解，開啟注解事務(wù)

@EnableTransactionManagement
@SpringBootApplication(exclude = PageHelperAutoConfiguration.class)
public class MultiDataSourceApplication {
    public static void main(String[] args) {
        SpringApplication.run(MultiDataSourceApplication.class, args);
    }
}

使用

在service層類或者方法上添加@Transactional注解。并指定屬性事務(wù)管理器transactionManager的值，根據(jù)使用不同的數(shù)據(jù)源，選擇不同的數(shù)據(jù)事務(wù)管理器

@Transactional(transactionManager = "masterTransactionManager")
public void insertUser() {
    // TODO 添加用戶業(yè)務(wù)操作
}
@Transactional(transactionManager = "clusterTransactionManager")
public void listUser() {
    // TODO 查詢用戶業(yè)務(wù)操作
}

思考: @Transactional只能指定一個(gè)事務(wù)管理器，并且注解不允許重復(fù)，所以就只能使用一個(gè)數(shù)據(jù)源的事務(wù)管理器了。那么對(duì)于一個(gè)方法涉及到多個(gè)數(shù)據(jù)源操作需要保證事務(wù)一致性的怎么辦呢？

實(shí)現(xiàn)跨數(shù)據(jù)源事務(wù)

基于注解+AOP使用編程式事務(wù)的方式實(shí)現(xiàn)跨數(shù)據(jù)源事務(wù)

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface MultiDataSourceTransactional {
    /**
     * 事務(wù)管理器數(shù)組
     */
    String[] transactionManagers();
}

首先多個(gè)數(shù)據(jù)源的事務(wù)分別都開起來，然后各事務(wù)分別去執(zhí)行對(duì)應(yīng)的sql（此所謂第一階段提交），最后如果都成功就把事務(wù)全部提交，只要有一個(gè)失敗就把事務(wù)都回滾——此所謂第二階段提交。

/**
 * 需要注意的點(diǎn)：
 * 1）聲明事務(wù)和提交事務(wù)或者回滾事務(wù)的順序應(yīng)該相反的，就是先進(jìn)后出，所以采用了棧來存儲(chǔ)。
 * 2）線程執(zhí)行結(jié)束后記得清空本地變量。
 * 3）可以參照@Transactional的那些屬性升級(jí)功能，比如隔離級(jí)別回滾異常等。
 */
@Component
@Aspect
public class MultiTransactionAop {
    /**
     * 線程本地變量：為什么使用棧？※為了達(dá)到后進(jìn)先出的效果※
     */
    private static final ThreadLocal<Stack<Map<DataSourceTransactionManager, TransactionStatus>>> THREAD_LOCAL = new ThreadLocal<>();
    private static Logger logger = LoggerFactory.getLogger(MultiTransactionAop.class);
    /**
     * 用于獲取事務(wù)管理器
     */
    @Autowired
    private ApplicationContext applicationContext;
    /**
     * 事務(wù)聲明
     */
    private DefaultTransactionDefinition def = new DefaultTransactionDefinition();
    {
        // 非只讀模式
        def.setReadOnly(false);
        // 事務(wù)隔離級(jí)別：采用數(shù)據(jù)庫(kù)的
        def.setIsolationLevel(TransactionDefinition.ISOLATION_DEFAULT);
        // 事務(wù)傳播行為
        def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
    }
    /**
     * 切點(diǎn)
     */
    @Pointcut("@annotation(cn.zysheep.datasource.anntation.MultiDataSourceTransactional)")
    public void pointcut() {
    }
    /**
     * 聲明事務(wù)
     *
     * @param transactional 注解
     */
    @Before("pointcut() && @annotation(transactional)")
    public void before(MultiDataSourceTransactional transactional) {
        // 根據(jù)設(shè)置的事務(wù)名稱按順序聲明，并放到ThreadLocal里
        String[] transactionManagerNames = transactional.transactionManagers();
        Stack<Map<DataSourceTransactionManager, TransactionStatus>> pairStack = new Stack<>();
        for (String transactionManagerName : transactionManagerNames) {
            DataSourceTransactionManager transactionManager = applicationContext.getBean(transactionManagerName, DataSourceTransactionManager.class);
            TransactionStatus transactionStatus = transactionManager.getTransaction(def);
            Map<DataSourceTransactionManager, TransactionStatus> transactionMap = new HashMap<>();
            transactionMap.put(transactionManager, transactionStatus);
            pairStack.push(transactionMap);
        }
        THREAD_LOCAL.set(pairStack);
    }
    /**
     * 后置增強(qiáng)，相當(dāng)于AfterReturningAdvice，方法退出時(shí)執(zhí)行
     *
     * 提交事務(wù)
     */
    @AfterReturning("pointcut()")
    public void afterReturning() {
        // ※棧頂彈出（后進(jìn)先出）
        Stack<Map<DataSourceTransactionManager, TransactionStatus>> pairStack = THREAD_LOCAL.get();
        while (!pairStack.empty()) {
            Map<DataSourceTransactionManager, TransactionStatus> pair = pairStack.pop();
            pair.forEach((key,value)->key.commit(value));
        }
        THREAD_LOCAL.remove();
    }
    /**
     * 異常拋出增強(qiáng)，相當(dāng)于ThrowsAdvice
     *
     * 回滾事務(wù)
     */
    @AfterThrowing(value = "pointcut()")
    public void afterThrowing() {
        // ※棧頂彈出（后進(jìn)先出）
        Stack<Map<DataSourceTransactionManager, TransactionStatus>> pairStack = THREAD_LOCAL.get();
        logger.info("=========================");
        logger.info("Pair Stack:{}", pairStack);
        logger.info("=========================");
        while (!pairStack.empty()) {
            Map<DataSourceTransactionManager, TransactionStatus> pair = pairStack.pop();
            pair.forEach((key,value)->key.rollback(value));
        }
        THREAD_LOCAL.remove();
    }
}

在事務(wù)的方法上添加前面我們的多數(shù)據(jù)源事務(wù)注解

 /**
     * 測(cè)試多數(shù)據(jù)源事務(wù)
     */
    @MultiDataSourceTransactional(transactionManagers = {"masterTransactionManager", "clusterTransactionManager"})
    @Override
    public void saveUser() {
        String rid = UUID.randomUUID().toString();
        User user = new User();
        user.setId(rid);
        userMapper.saveUser(user);
        Log log = new Log();
        log.setId(rid);
        logMapper.saveLog(log);
        throw new RuntimeException();
    }

到此這篇關(guān)于SpringBoot整合Mybatis實(shí)現(xiàn)多數(shù)據(jù)源配置與跨數(shù)據(jù)源事務(wù)實(shí)例的文章就介紹到這了,更多相關(guān)SpringBoot多數(shù)據(jù)源配置內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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