如何在java中使用数据源对象获取数据库配置

Question

我陷入了与java中的数据源对象相关的问题.我在数据源对象(org.apache.tomcat.jdbc.pool.DataSource)中设置了数据源连接参数.我希望在调用getConnection方法之前从数据源对象获取这些参数,如果它捕获异常,则在catch内部记录有意义的调试信息.

以下是我尝试过的代码.我可以从元数据中获取所有连接参数,如下所示[例如: - connection.getMetaData().getURL()],但我想捕获异常,并记录url,密码,用户名作为日志,如果getConnection()抛出异常.因此,我需要在尝试创建数据库连接之前从数据源对象获取这些信息.

try {
        // try to get the lookup name. If error empty string will be returned
        jndiLookupName = connectionProperties.getProperty(RDBMSConstants.PROP_JNDI_LOOKUP_NAME);
        datasource = InitialContext.doLookup(jndiLookupName);

        connection = datasource.getConnection(); // WHEN THIS THROWS EXCEPTION...

        logger.info(connection.getMetaData().getURL()); // these won't work since exception already thrown.
        logger.info(connection.getMetaData().getUserName());
        logger.info(connection.getMetaData().getDriverName());
        logger.info(connection.getMetaData().getDriverVersion());

        isConnected = true; // if no errors
        logger.info("JDBC connection established with jndi config " + jndiLookupName);

    } catch (SQLException e) {

        //...I WANT ALL CONNECTION PARAMETERS (URL,PASSWORD,USERNAME) HERE

        throw new SQLException("Connecting to database failed with jndi lookup", e);
    }

当我远程调试我得到数据源对象如下..

org.apache.tomcat.jdbc.pool.DataSource@d47feb3{ConnectionPool[defaultAutoCommit=null; defaultReadOnly=null; defaultTransactionIsolation=-1; defaultCatalog=null; driverClassName=com.mysql.jdbc.Driver; maxActive=100; maxIdle=8; minIdle=0; initialSize=0; maxWait=30000; testOnBorrow=false; testOnReturn=false; timeBetweenEvictionRunsMillis=5000; numTestsPerEvictionRun=0; minEvictableIdleTimeMillis=60000; testWhileIdle=false; testOnConnect=false; password=********; url=jdbc:mysql://localhost/wso2_mb_1; username=a; validationQuery=null; validationQueryTimeout=-1; validatorClassName=null; validationInterval=30000; accessToUnderlyingConnectionAllowed=true; removeAbandoned=false; removeAbandonedTimeout=60; logAbandoned=false; connectionProperties=null; initSQL=null; jdbcInterceptors=ConnectionState;StatementFinalizer;org.wso2.carbon.ndatasource.rdbms.ConnectionRollbackOnReturnInterceptor;; jmxEnabled=true; fairQueue=true; useEquals=true; abandonWhenPercentageFull=0; maxAge=0; useLock=false; dataSource=null; dataSourceJNDI=null; suspectTimeout=0; alternateUsernameAllowed=false; commitOnReturn=false; rollbackOnReturn=false; useDisposableConnectionFacade=true; logValidationErrors=false; propagateInterruptState=false; ignoreExceptionOnPreLoad=false; }

我可以看到所有的url,用户名和密码参数都在那里,但我无法得到那些.有没有办法从数据源对象中获取这些值.

Answer 1

投射到具体实施的DataSource- tomcat的数据源汇集提供了访问username,url等等(见数据源的详细信息):

if (dataSource instanceof org.apache.tomcat.jdbc.pool.DataSource) {
    org.apache.tomcat.jdbc.pool.DataSource tcDataSource = (org.apache.tomcat.jdbc.pool.DataSource)dataSource;
    logger.info(tcDataSource.getUrl());
    logger.info(tcDataSource.getUsername());
    ...
}