检查MySQL数据库连接是否已关闭后，立即关闭它

Question

我一直在为我的java应用程序做大量的工作来提高数据库连接的稳定性等等。有一个问题仍然困扰着用户，这似乎很常见，我的代码而不是他们的数据库服务器的问题

我们正在使用jdbc-pool。

错误：

Database connection error: Connection has already been closed.
 java.sql.SQLException: Connection has already been closed.
 at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:118)
 at $Proxy12.commit(Unknown Source)
 at me.botsko.prism.actionlibs.ActionRecorder.insertActionsIntoDatabase(ActionRecorder.java:201)
 at me.botsko.prism.actionlibs.ActionRecorder.save(ActionRecorder.java:81)
 at me.botsko.prism.actionlibs.ActionRecorder.run(ActionRecorder.java:230)
 at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftTask.run(CraftTask.java:53)
 at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)

与之相关的代码：

public void insertActionsIntoDatabase() {

    PreparedStatement s = null;
    Connection conn = null;

    try {

        if( !queue.isEmpty() ){

            conn = Prism.dbc();
            if(conn == null || conn.isClosed()){
                // try to re-open conn
                return;
            }
            conn.setAutoCommit(false);
            s = conn.prepareStatement("QUERY HERE");
            while (!queue.isEmpty()){
                s.executeBatch(); // Execute every x items.
            }

            s.executeBatch();
            conn.commit();

        }
    } catch (SQLException e){
        plugin.handleDatabaseException( e );
    } finally {
        if(s != null) try { s.close(); } catch (SQLException e) {}
        if(conn != null) try { conn.close(); } catch (SQLException e) {}
    }
}

我一直在检查连接是否已关闭，但不知何故有些事情已经过去了。此代码每次运行时都会抓取一个新的池连接，因此它不使用应用程序其他部分使用的连接。