dynamic-datasource-spring-boot-starter源码分析-动态加载数据库

地址：https://blog.csdn.net/chinawangfei/article/details/122830408

pom.xml

     <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>

 

spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DynamicDataSourceAutoConfiguration

 

DynamicDataSourceAutoConfiguration.java

  @Bean
    public DynamicDataSourceProvider ymlDynamicDataSourceProvider() {
        return new YmlDynamicDataSourceProvider(properties.getDatasource());
    }

    @Bean
    @ConditionalOnMissingBean
    public DataSource dataSource() {
        DynamicRoutingDataSource dataSource = new DynamicRoutingDataSource();
        dataSource.setPrimary(properties.getPrimary());
        dataSource.setStrict(properties.getStrict());
        dataSource.setStrategy(properties.getStrategy());
        dataSource.setP6spy(properties.getP6spy());
        dataSource.setSeata(properties.getSeata());
        return dataSource;
    }

   // 使用DS 动态获取

　　@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
　　@Bean
　　@ConditionalOnProperty(prefix = DynamicDataSourceProperties.PREFIX + ".aop", name = "enabled", havingValue = "true", matchIfMissing = true)
　　public Advisor dynamicDatasourceAnnotationAdvisor(DsProcessor dsProcessor) {
   　　 DynamicDatasourceAopProperties aopProperties = properties.getAop();
　　    DynamicDataSourceAnnotationInterceptor interceptor = new DynamicDataSourceAnnotationInterceptor(aopProperties.getAllowedPublicOnly(), dsProcessor);
　　    DynamicDataSourceAnnotationAdvisor advisor = new DynamicDataSourceAnnotationAdvisor(interceptor, DS.class);
   　　 advisor.setOrder(aopProperties.getOrder());
　　    return advisor;
　　}

 

DynamicRoutingDataSource.java

    @Override
    public void afterPropertiesSet() throws Exception {
        // 检查开启了配置但没有相关依赖
        checkEnv();
        // 添加并分组数据源
        Map<String, DataSource> dataSources = new HashMap<>(16);
        for (DynamicDataSourceProvider provider : providers) {
            dataSources.putAll(provider.loadDataSources());
        }
        for (Map.Entry<String, DataSource> dsItem : dataSources.entrySet()) {
            addDataSource(dsItem.getKey(), dsItem.getValue());
        }
        // 检测默认数据源是否设置
        if (groupDataSources.containsKey(primary)) {
            log.info("dynamic-datasource initial loaded [{}] datasource,primary group datasource named [{}]", dataSources.size(), primary);
        } else if (dataSourceMap.containsKey(primary)) {
            log.info("dynamic-datasource initial loaded [{}] datasource,primary datasource named [{}]", dataSources.size(), primary);
        } else {
            log.warn("dynamic-datasource initial loaded [{}] datasource,Please add your primary datasource or check your configuration", dataSources.size());
        }
    }

 

DynamicDataSourceLoading.java 是自定义的数据源

/**
 * 子数据源加载*/
@Configuration
public class DynamicDataSourceLoading {

    @Autowired
    SourceProperties sourceProperties;

    @Bean
    public DynamicDataSourceProvider jdbcDynamicDataSourceProvider() {
        return new AbstractJdbcDataSourceProvider(sourceProperties.getDriverClassName(), sourceProperties.getUrl(), sourceProperties.getUsername(), sourceProperties.getPassword()) {
            @Override
            protected Map<String, DataSourceProperty> executeStmt(Statement statement) throws SQLException {
                ResultSet rs = statement.executeQuery("select s.slave, s.username, s.password, s.url_prepend, s.url_append, s.driver_class_name from xy_tenant_source s where s.status = '0' and s.del_flag = '0'");
                Map<String, DataSourceProperty> map = new HashMap<String, DataSourceProperty>();
                while (rs.next()) {
                    String name = rs.getString("slave");
                    String username = rs.getString("username");
                    String password = rs.getString("password");
                    String url = rs.getString("url_prepend").concat(StringUtils.trim(rs.getString("url_append")));
                    String driver = rs.getString("driver_class_name");
                    DataSourceProperty property = new DataSourceProperty();
                    property.setUsername(username);
                    property.setPassword(password);
                    property.setUrl(url);
                    property.setDriverClassName(driver);
                    map.put(name, property);
                }
                return map;
            }
        };
    }
}

 

DSUtils.java 自定义

public class DSUtils {
    protected static Logger logger = LoggerFactory.getLogger(DSUtils.class);

    /**
     * 添加一个数据源到数据源库中
     *
     * @param source 数据源对象
     */
    public static void addDs(Source source) {
        try {
            DefaultDataSourceCreator dataSourceCreator = SpringUtils.getBean(DefaultDataSourceCreator.class);
            DataSourceProperty dataSourceProperty = new DataSourceProperty();
            BeanUtils.copyProperties(source, dataSourceProperty);
            DataSource dataSource = SpringUtils.getBean(DataSource.class);
            DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
            dataSource = dataSourceCreator.createDataSource(dataSourceProperty);
            ds.addDataSource(source.getSlave(), dataSource);
        } catch (Exception e) {
            e.printStackTrace();
            throw new ServiceException("数据源添加失败");
        }
    }

    /**
     * 从数据源库中删除一个数据源
     *
     * @param slave 数据源编码
     */
    public static void delDs(String slave) {
        try {
            DynamicRoutingDataSource ds = (DynamicRoutingDataSource) SpringUtils.getBean(DataSource.class);
            ds.removeDataSource(slave);
        } catch (Exception e) {
            e.printStackTrace();
            throw new ServiceException("数据源删除失败");
        }
    }

    /**
     * 获取当前数据源库中所有数据源
     */
    public static void getDs() {
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) SpringUtils.getBean(DataSource.class);
        ds.getDataSources().keySet().forEach(System.out::println);
    }

    /**
     * 获取当前线程数据源名称
     */
    public static String getNowDsName() {
        return DynamicDataSourceContextHolder.peek();
    }

 

 

MyDynamicDataSourceConfig.java 自定义

/**
 * 源访问策略注入*/
@Configuration
@AutoConfigureBefore(DynamicDataSourceAutoConfiguration.class)
public class MyDynamicDataSourceConfig {

    @Bean
    public DsProcessor dsProcessor() {
        DsHeaderProcessor headerProcessor = new DsHeaderProcessor();
        DsSessionProcessor sessionProcessor = new DsSessionProcessor();
        DsSpelExpressionProcessor spelExpressionProcessor = new DsSpelExpressionProcessor();
        DsIsolateExpressionProcessor isolateExpressionProcessor = new DsIsolateExpressionProcessor();
        DsMainExpressionProcessor mainExpressionProcessor = new DsMainExpressionProcessor();
        headerProcessor.setNextProcessor(sessionProcessor);
        sessionProcessor.setNextProcessor(spelExpressionProcessor);
        spelExpressionProcessor.setNextProcessor(isolateExpressionProcessor);
        isolateExpressionProcessor.setNextProcessor(mainExpressionProcessor);
        return headerProcessor;
    }
    /**
     * 解决warn- discard long time none received connection xxx
     * druid会优先使用pingMethod方法来检查空闲连接
     * 通过设置druid.mysql.usePingMethod=false，让其使用validationQuery语句
     */
    @PostConstruct
    public void setProperty() {
        System.setProperty("druid.mysql.usePingMethod","false");
    }
}

 

 

@Component
public class DsMainExpressionProcessor extends DsProcessor {

    @Override
    public boolean matches(String key) {
        return key.startsWith("#main");
    }

    @Override
    public String doDetermineDatasource(MethodInvocation invocation, String key) {
        return TenantConstants.Source.MAIN.getCode();
    }
}

@Component
public class DsIsolateExpressionProcessor extends DsProcessor {

    @Override
    public boolean matches(String key) {
        return key.startsWith("#isolate");
    }

    @Override
    public String doDetermineDatasource(MethodInvocation invocation, String key) {
        String sourceName = SecurityUtils.getSourceName();
        return StrUtil.isNotEmpty(sourceName) ? sourceName : DSUtils.getNowDsName();
    }
}