标签: apache-commons-dbcp

具体来说,当我返回到池的连接时,dbcp(和其他连接池)是否会为我关闭语句和结果集？

或者我应该自己关闭这些？

我在Tomcat中有一个DBCP连接池.问题是当连接短暂丢失时,应用程序被破坏,因为DBCP在连接时不会再尝试重新连接.我可以让DBCP自动重新连接吗？

我们使用org.apache.commons.dbcp.BasicDataSource作为Spring中数据源的父类.

是否可以在"url"或DBCP数据源中的另一个属性中指定要使用的模式？

我们看到我们的数据库连接因org.apache.commons.dbcp.BasicDataSource插槽写入错误而死的情况:

com.microsoft.sqlserver.jdbc.SQLServerException: Connection reset by peer: socket write error

当然,所有后续写入连接的尝试都会失败:

com.microsoft.sqlserver.jdbc.SQLServerException: The connection is closed.

更新代码以捕获此类异常并在发生新连接时请求它,它再次失败.我是否正确怀疑DataSource#getConnection()每次呼叫时呼叫实际上并没有提供新的连接？是不是只是重用现有的连接,这是关闭的？

如果我是正确的,什么是丢弃旧连接并请求新连接的正确方法？

编辑:这是我想知道的更简洁的版本:

Connection c1, c2;
c1 = DatabaseManager.getConnection();
// c1.close() not called
c2 = DatabaseManager.getConnection(); 

"c1 == c2"是真实的陈述吗？或者分配了两个连接？如果是后者,那么像这样的代码表示"连接池泄漏":

Connection c1;
c1 = DatabaseManager.getConnection();
// c1.close() not called
c1 = DatabaseManager.getConnection();

我使用以下设置在JBoss EAP服务器中部署了Spring应用程序:

<bean:bean id="userDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <bean:property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/>
    <bean:property name="url" value="jdbc:oracle:thin:@10.8.1.5:1521:DB"/>
    <bean:property name="username" value="WEBDB"/>
    <bean:property name="password" value="WEBDB"/>
</bean:bean>

如何配置连接池的最小和最大大小？

BasicDataSource的任何参考或任何最佳实践都将有很大帮助.

我的项目设置是 -

1. Spring JDBC用于持久化
2. Apache DBCP 1.4用于连接池
3. Linux上的Mysql 5

这是我的应用程序的日志,它捕获与数据库的交互.

2013-01-29 15:52:21,549 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.core.JdbcTemplate - Executing SQL query [SELECT id from emp]
2013-01-29 15:52:21,558 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.datasource.DataSourceUtils - Fetching JDBC Connection from DataSource
2013-01-29 15:52:31,878  INFO http-bio-8080-exec-3 jdbc.connection - 1. Connection opened  org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
2013-01-29 15:52:31,878 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  1 (1)
2013-01-29 15:52:31,895  INFO http-bio-8080-exec-3 jdbc.connection - 1. Connection closed  org.apache.commons.dbcp.DelegatingConnection.close(DelegatingConnection.java:247)
2013-01-29 15:52:31,895 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  none
2013-01-29 15:52:41,950  INFO http-bio-8080-exec-3 jdbc.connection - 2. …

MysqlConnectionPoolDataSource和C3p0,BoneCP或dbcp库之间的连接池有什么区别？我不明白为什么使用库,如果mysql连接器给出连接池.

I have read through various Stackover flow Questions and contents on the web on similar problem. However, I couldnt find useful hints that would allow me to narrow down on my problem. Here is my usecase which results in this error.

2 entities Campus and Programs --> One-to-many relation from Campus to Program and One-to-one from Program to Campus.

i am trying to create multiple programs associated with campuses. Each insert will create a new program with same details and …

如果我们执行getConnection(),则使用DBCP中的BasicDataSource,在finally块中我们关闭连接,它确实会返回到池的连接,或者是否关闭连接.我正在检查的代码片段就是这个

try {
        Connection conn1 = getJdbcTemplate().getDataSource()
                .getConnection();
        //Some code to call stored proc 

    } catch (SQLException sqlEx) {
        throw sqlEx;
    } finally {
        try {
            if (conn != null) {
                conn.close();
            }
        } catch (SQLException ex1) {
            throw ex1;
        }

    }

我正在检查BasicDataSource的源代码,我到达了这个连接的包装类.

private class PoolGuardConnectionWrapper extends DelegatingConnection {

    private Connection delegate;

    PoolGuardConnectionWrapper(Connection delegate) {
        super(delegate);
        this.delegate = delegate;
    }

    public void close() throws SQLException {
        if (delegate != null) {
            this.delegate.close();
            this.delegate = null;
            super.setDelegate(null);
        }
    }

委托对象,如果是java.sql.Connection类型.包装器代码调用委托的close方法,该方法将关闭集合而不是将连接返回到池.这是DBCP的已知问题,还是我错误地阅读了源代码请告诉我.

谢谢

我有一个简单的webapp,它从tomcat JDBC数据源获取连接.为了跟踪连接使用情况,我打算在打开和关闭连接时实现日志记录.记录应该打印这样的东西.

20151230143623.947[Thread-3] INFO  [DataSourceManager:19] Opened connection identified by id : BlahBlahBlah1
20151230143623.947[Thread-3] INFO  [DataSourceManager:19] Closed connection identified by id : BlahBlahBlah1

我的开放和关闭方法是这样的.

Connection openConnection(String JNDILookupName) throws Exception {
    Connection connection = DataSourceManager.getConnection(JNDILookupName);
    logDBOperation("Opened", connection.toString());
    return connection;
}
Connection closeConnection(String JNDILookupName) throws Exception {
    connection.close();
    logDBOperation("Closed", connection.toString());
}
void logDBOperation(String operation, String connecitonName){
    logger.info(operation+" connection identified by id : "+connectionName);
}

在这里,我使用Log connection.toString()作为Connection的唯一名称.但我想知道是否有更好的方法来做到这一点.