java.sql.SQLException: Io exception: Invalid Packet Lenght_oracle java.sql.sqlexception: must be logged on to-优快云博客

本文介绍了在使用Oracle JDBC驱动时遇到的多种异常情况及其原因，这些异常主要由多个线程同时使用同一个Connection对象引起。文章提供了两种解决方案：一是确保同一时刻只有一个线程使用JDBC驱动；二是升级到更高版本的驱动，例如10.2.0.4版本，该版本能有效避免此类问题。

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Similar exceptions are :

1. java.io.IOException: Io exception: Unexpected packet

2. java.sql.SQLException: Protocol violation

3. java.sql.SQLException: Io exception: Bad packet type

4. java.sql.SQLException: Bigger type length than Maximum

5. java.sql.SQLException: Io exception: Invalid Packet Lenght

6. java.sql.SQLException: Closed Connection

7. java.sql.SQLException: Closed Statement

8. java.sql.SQLException: Refcursor value is invalid

9. java.sql.SQLException: Io exception: Size Data Unit (SDU) mismatch

10. java.sql.SQLException: Must be logged on to server

All these occur almost with same reason. It is caused when more than one thread is trying to make simultaneous use of the thin Oracle JDBC driver via the same Connection object.

To correct this problem we have to ensure that only one thread of execution was making use of the JDBC driver at a time through the same Connection OR upgrade to a later version of the driver.

Further investigation says, with JDBC driver version is 9.2.0.2.0 it is reproducible and 9.2.0.3.0 is free from this. Any ways, it is advisable to go with latest jdbc driver version i.e. 10.2.0.4 which can solve this issue.

Multi-thread programming needs this as quick note.