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SpringBootの複数データソース切り替えの実装方法

王林
王林転載
2023-05-22 18:22:061537ブラウズ
    #設定ファイル (YML)

    spring:
      datasource:
        default-db-key: voidme
        multi-db:
          - voidme:
              driver-class-name: com.mysql.cj.jdbc.Driver
              username: root
              password: root
              url: jdbc:mysql://192.168.42.153:3306/voidme?characterEncoding=utf8&autoReconnect=true&failOverReadOnly=false&maxReconnects=10&useSSL=false
          - xcdef:
              driver-class-name: com.mysql.cj.jdbc.Driver
              username: root
              password: root
              url: jdbc:mysql://192.168.42.153:3306/xcdef?characterEncoding=utf8&autoReconnect=true&failOverReadOnly=false&maxReconnects=10&useSSL=false
    
    
    mybatis:
      #1.classpath:只会到你的classes路径中查找找文件。
      #2.classpath*:不仅会到classes路径,还包括jar文件中(classes路径)进行查找。
      mapper-locations: classpath*:/mapper/**/*Mapper.xml    # mapper映射文件位置
      type-aliases-package: com.**.entity    # 实体类所在的位置
      configuration:
        log-impl: org.apache.ibatis.logging.stdout.StdOutImpl   #用于控制台打印sql语句
        map-underscore-to-camel-case: true #开启将带有下划线的表字段 映射为驼峰格式的实体类属性

    コア コード

    SpringBootの複数データソース切り替えの実装方法

    DynamicDataSource

    このクラスはデータソース(コア)の取得に使用されます

    package com.dynamicdatadource.dynamic;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
    
    public class DynamicDataSource extends AbstractRoutingDataSource {
    
        @Value("${spring.datasource.default-db-key}")
        private String defaultDbKey;
    
        @Override
        protected Object determineCurrentLookupKey() {
            String currentDb = DynamicDataSourceService.currentDb();
            if (currentDb == null) {
                return defaultDbKey;
            }
            return currentDb;
        }
    }

    DynamicDataSourceService

    このクラスはデータソース切り替えツールであり、スレッド分離を行っているので心配する必要はありませんマルチスレッド データ ソースの混乱。問題

    package com.dynamicdatadource.dynamic;
    
    import com.application.ApplicationContextProvider;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    
    import javax.sql.DataSource;
    import java.util.HashMap;
    import java.util.Map;
    
    public class DynamicDataSourceService  {
        private static final Logger log = LoggerFactory.getLogger(DynamicDataSourceService.class);
    
        private static final Map<Object, Object> dataSources = new HashMap<>();
        private static final ThreadLocal<String> dbKeys = ThreadLocal.withInitial(() -> null);
    
        /**
         * 动态添加一个数据源
         *
         * @param name       数据源的key
         * @param dataSource 数据源对象
         */
        public static void addDataSource(String name, DataSource dataSource) {
            DynamicDataSource dynamicDataSource = ApplicationContextProvider.getApplicationContext().getBean(DynamicDataSource.class);
            dataSources.put(name, dataSource);
            dynamicDataSource.setTargetDataSources(dataSources);
            dynamicDataSource.afterPropertiesSet();
            log.info("添加了数据源:{}",name);
        }
    
        /**
         * @param name   数据源的key
         * @param driverClassName  驱动
         * @param url     数据库连接地址
         * @param username   数据库账户
         * @param password   数据库密码
         */
        public static void addDataSource(String name, String driverClassName,String url,String username,String password) {
            DataSourceBuilder<?> builder = DataSourceBuilder.create();
            builder.driverClassName(driverClassName);
            builder.username(username);
            builder.password(password);
            builder.url(url);
            addDataSource(name,builder.build());
            log.info("添加了数据源:{}",name);
        }
        /**
         * 切换数据源
         */
        public static void switchDb(String dbKey) {
            dbKeys.set(dbKey);
        }
    
        /**
         * 重置数据源(切换为默认的数据源)
         */
        public static void resetDb() {
            dbKeys.remove();
        }
    
        /**
         * 获取当前数据源的key
         */
        public static String currentDb() {
            return dbKeys.get();
        }
    }

    DynamicDataSourceConfig

    データ ソースを Springboot に構成し、Mybaitis 構成を初期化する

    package com.dynamicdatadource.dynamic;
    
    import lombok.Data;
    import org.apache.ibatis.logging.Log;
    import org.mybatis.spring.SqlSessionFactoryBean;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
    import org.springframework.jdbc.datasource.DataSourceTransactionManager;
    import org.springframework.transaction.PlatformTransactionManager;
    
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    
    @Configuration
    @ConfigurationProperties(prefix = "mybatis")
    @Data
    public class DynamicDataSourceConfig {
    
        private String mapperLocations;
        private String typeAliasesPackage;
        @Data
        public class MybatisConfiguration{
            private String logImpl;
            private boolean mapUnderscoreToCamelCase;
        }
        private  MybatisConfiguration configuration=new MybatisConfiguration();
    
    
        /**
         * 动态数据源
         */
        @Bean
        public DynamicDataSource dynamicDataSource() {
            DynamicDataSource dataSource = new DynamicDataSource();
            Map<Object, Object> targetDataSources = new HashMap<>();
            dataSource.setTargetDataSources(targetDataSources);
            return dataSource;
        }
    
        /**
         * 会话工厂Mybaitis
         */
        @Bean
        public SqlSessionFactoryBean sqlSessionFactoryBean() throws IOException, ClassNotFoundException {
            org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
            configuration.setMapUnderscoreToCamelCase(this.configuration.isMapUnderscoreToCamelCase()); //开启驼峰命名
            configuration.setLogImpl((Class<? extends Log>) Class.forName(this.configuration.getLogImpl())); //控制台打印sql日志
            SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
            sqlSessionFactoryBean.setDataSource(dynamicDataSource());
            sqlSessionFactoryBean.setConfiguration(configuration);
            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            sqlSessionFactoryBean.setMapperLocations(resolver.getResources(mapperLocations));
            sqlSessionFactoryBean.setTypeAliasesPackage(typeAliasesPackage);
            return sqlSessionFactoryBean;
        }
    
        /**
         * 事务管理器
         */
        @Bean
        public PlatformTransactionManager transactionManager() {
            return new DataSourceTransactionManager(dynamicDataSource());
        }
    }

    YML データベース構成クラスをロードする

    package com.dynamicdatadource.config;
    
    import com.dynamicdatadource.dynamic.DynamicDataSourceService;
    import lombok.Data;
    import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.PostConstruct;
    import javax.sql.DataSource;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    
    @Component
    @Data
    @ConfigurationProperties(prefix = "spring.datasource")
    public class YmlDataSourceProvider  {
    
        private List<Map<String, DataSourceProperties>> multiDb;
    
        private DataSource buildDataSource(DataSourceProperties prop) {
            DataSourceBuilder<?> builder = DataSourceBuilder.create();
            builder.driverClassName(prop.getDriverClassName());
            builder.username(prop.getUsername());
            builder.password(prop.getPassword());
            builder.url(prop.getUrl());
            return builder.build();
        }
    
        public void initDataSource() {
            multiDb.forEach(map -> {
                Set<String> keys = map.keySet();
                keys.forEach(key -> {
                    DataSourceProperties properties = map.get(key);
                    DataSource dataSource = buildDataSource(properties);
                    DynamicDataSourceService.addDataSource(key, dataSource);
                });
            });
        }
    
        //在构造函数之后执行
        @PostConstruct
        public void init() {
            initDataSource();
        }
    }

    aop 切り替え

    package com.dynamicdatadource.aop;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    @Target({ElementType.METHOD,ElementType.TYPE})//作用:方法和类
    @Retention(RetentionPolicy.RUNTIME)
    public @interface DynamicDataSourceAnno {
        String key() default "";
    }
    package com.dynamicdatadource.aop;
    import com.dynamicdatadource.dynamic.DynamicDataSourceService;
    import org.apache.commons.lang.StringUtils;
    import org.aspectj.lang.ProceedingJoinPoint;
    import org.aspectj.lang.annotation.Around;
    import org.aspectj.lang.annotation.Aspect;
    import org.aspectj.lang.annotation.Pointcut;
    import org.aspectj.lang.reflect.MethodSignature;
    import org.springframework.stereotype.Component;
    
    // 用于单独的请求或者类进行切换数据库
    @Aspect
    @Component
    public class DynamicDataSourceAspect {
        @Pointcut("@annotation(com.dynamicdatadource.aop.DynamicDataSourceAnno)")
        public void dynamicDataSourceAnno() {
        }
    
        @Around("dynamicDataSourceAnno()")
        public Object DynamicDataSourceAspectAroundAnno(ProceedingJoinPoint joinPoint) {
            Object object = null;
            try {
                MethodSignature signature = (MethodSignature)joinPoint.getSignature();
                DynamicDataSourceAnno dynamicDataSourceAnno  = signature.getMethod().getAnnotation(DynamicDataSourceAnno.class);
                String key = dynamicDataSourceAnno.key();
                if (StringUtils.isNotBlank(key)) {
                    //切换为指定数据库
                    DynamicDataSourceService.switchDb(key);
                }
                object = joinPoint.proceed();
            } catch (Throwable e) {
                e.printStackTrace();
            }finally {
                //还原为默认配置
                DynamicDataSourceService.resetDb();
            }
            return object;
        }
        // 还可以扩展包路径切换
    }

    効果

    プログラムを実行すると、データ ソースがデータ ソース リストに追加されます

    SpringBootの複数データソース切り替えの実装方法 ##Extension

    MysqlDataSourceInitialize

    データベースから構成情報をクエリし、それをデータ ソース リストに動的に追加します

    package com.dao.config;
    
    import com.dao.DatasourceDao;
    import com.dynamicdatadource.aop.DynamicDataSourceAnno;
    import com.dynamicdatadource.dynamic.DynamicDataSourceService;
    import com.entity.DataSourceEneity;
    import org.springframework.beans.factory.InitializingBean;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.ApplicationArguments;
    import org.springframework.boot.ApplicationRunner;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.PostConstruct;
    import javax.sql.DataSource;
    import java.util.List;
    
    //从数据库中查询出全部的数据源,添加到数据源容器中
    
    /**
     * 表结构如下:
     *
     * CREATE TABLE `t_datasource` (
     *   `id` int(11) NOT NULL,
     *   `key` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;绑定的key,用于数据源的切换&#39;,
     *   `url` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;数据库连接地址&#39;,
     *   `username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;数据库用户名&#39;,
     *   `password` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;数据库密码&#39;,
     *   `driverClassName` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;数据库驱动&#39;,
     *   `type` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT &#39;数据库类型:  mysql ,oracle,..&#39;,
     *   `state` int(2) NOT NULL COMMENT &#39;是否可用: 1可用 ,2不可用&#39;,
     *   PRIMARY KEY (`id`),
     *   UNIQUE KEY `key` (`key`)
     * ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
     *
     * 上表要放入到默认数据源中的数据库里才行
     */
    @Component
    public class MysqlDataSourceInitialize implements ApplicationRunner  {
    
        @Autowired
        private DatasourceDao datasourceDao;
    
        //项目启动后执行初始化数据源
        @Override
        public void run(ApplicationArguments args) throws Exception {
            try {
                List<DataSourceEneity> dataSources = datasourceDao.getDataSources();
                for (DataSourceEneity dataSource : dataSources) {
                    DynamicDataSourceService.addDataSource(dataSource.getKey(),dataSource.getDataSource());
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    DataSourceEneity エンティティ クラス

    @Data
    public class DataSourceEneity {
        private int id;
        private String key;
        private String url;
        private String username;
        private String password;
        private String driverClassName;
        private String type;
        private int state;
    
        public  DataSource getDataSource() {
            DataSourceBuilder<?> builder = DataSourceBuilder.create();
            builder.driverClassName(driverClassName);
            builder.username(username);
            builder.password(password);
            builder.url(url);
            return  builder.build();
        }
    }

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