SpringBoot多数据源切换怎么实现

本篇内容主要讲解"SpringBoot多数据源切换怎么实现"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"SpringBoot多数据源切换怎么实现"吧!

配置文件(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=falsemybatis:  #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

核心代码

DynamicDataSource

这个类用于获取数据源的(核心)

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

这个类是数据源切换工具,我们做了线程隔离了所以不用担心多线程数据源会混乱的问题

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 dataSources = new HashMap<>();    private static final ThreadLocal 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

将数据源配置到springboot中和初始化Mybaitis配置

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")@Datapublic 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 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) 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());    }}

加载YML数据库配置类

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> 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 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切换

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@Componentpublic 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}

效果

运行程序之后,就会将数据源加入到数据源列表中了

扩展

MysqlDataSourceInitialize

从数据库中将配置信息查询出来,然后动态添加到数据源列表中

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 '绑定的key,用于数据源的切换', *   `url` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '数据库连接地址', *   `username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '数据库用户名', *   `password` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '数据库密码', *   `driverClassName` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '数据库驱动', *   `type` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '数据库类型:  mysql ,oracle,..', *   `state` int(2) NOT NULL COMMENT '是否可用: 1可用 ,2不可用', *   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 */@Componentpublic 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 dataSources = datasourceDao.getDataSources();            for (DataSourceEneity dataSource : dataSources) {                DynamicDataSourceService.addDataSource(dataSource.getKey(),dataSource.getDataSource());            }        } catch (Exception e) {            e.printStackTrace();        }    }}

DataSourceEneity实体类

@Datapublic 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();    }}

到此，相信大家对"SpringBoot多数据源切换怎么实现"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！