SQL 尝试在 finally 子句中关闭连接时出现异常

Question

我在里面有一些 OAF 代码，我正在启动 sql 连接，但是当我试图关闭它时，它抛出 sql 异常。这是代码。

    try
    {
        conn = 
        (OracleConnection)oadbtransactionimpl.getJdbcConnection();
        String queryForEmpty = 
            "select ... query here"; 
        projectDetailsStatment = 
                conn.prepareStatement(queryForEmpty);
        projectDetailsStatment.setString(1,sprojectid);
        ResultSet rs = projectDetailsStatment.executeQuery();

    }
    catch(SQLException e)
   {
       String sqlErrMsg = e.getMessage();
       throw new OAException((new StringBuilder()).append("handle exception here:").append(sqlErrMsg).toString(), (byte)0);
   }
   finally
   {
      conn.close(); // throws exception here
   }

Answer 1

尝试用 try and catch 子句括起结束代码

    try
    {
        conn = 
        (OracleConnection)oadbtransactionimpl.getJdbcConnection();
        String queryForEmpty = 
            "select ... query here"; 
        projectDetailsStatment = 
                conn.prepareStatement(queryForEmpty);
        projectDetailsStatment.setString(1,sprojectid);
        ResultSet rs = projectDetailsStatment.executeQuery();

    }
    catch(SQLException e)
   {
       String sqlErrMsg = e.getMessage();
       throw new OAException((new StringBuilder()).append("Exception in Finding Project Type:").append(sqlErrMsg).toString(), (byte)0);
   }
   finally
   {
      try{
      conn.close(); // throws exception here
      }
        catch(SQLException e)
      {
        //your code here
      }
   }

Answer 2

任何 JDBC 操作的基本方案都非常简单：

取得联系。
创建声明。
执行语句得到ResultSet。
处理结果集。
关闭一切：ResultSet，语句和连接。

错误的解决方案

public void handleJDBC()  {
    try {
        DataSource dataSource = getDataSource();
        Connection connection = dataSource.getConnection();
        operation(connection)
        connection.close();
    } catch (SQLException e) {
        //do something here
    }
}

良好实践

finally {
        if (connection != null) {
            try {
            connection.close();
        } catch (SQLException e) {
            if (exception != null) {
                exception = new DoubleException(exception, e);
            } else {
                exception = e;
            }
        }
        }
    }
    if (exception != null) {
        throw exception;
    }

SQL 尝试在 finally 子句中关闭连接时出现异常

SQL exception occurs when trying to close the connection in finally clause

java

oaf