CODEWITHSUNDEEP
javatransactionsdatabase-connection
Antonio
Antonio

Reputation: 341

Does Java Connection.close rollback?

Does Java Connection.close rollback into a finally block?.

I know .Net SqlConnection.close does it.

With this I could make try/finally blocks without catch...

Example:

try {
    conn.setAutoCommit(false);
    ResultSet rs = executeQuery(conn, ...);
    ....
    executeNonQuery(conn, ...);
    ....

    conn.commit();
} finally {
   conn.close();
}

Upvotes: 19

Views: 24149

Answers (6)

Adnan Memon
Adnan Memon

Reputation: 483

For MySQL JDBC, the implementation rolls back the connection if closed without a call to commit or rollback methods.

Upvotes: 0

lbergnehr
lbergnehr

Reputation: 1598

The behavior is completely different between different databases. Examples:

Oracle

The transaction is committed when closing the connection with an open transaction (as @Mr. Shiny and New 安宇 stated.

SQL Server

Calling the close method in the middle of a transaction causes the transaction to be rolled back.

close Method (SQLServerConnection)

Upvotes: 7

Mean
Mean

Reputation: 1

It is useless to rollback in finally block. After you commit, and commit is successful, why to roll back? So if i were you, i would rollback in catch block.

Upvotes: -1

Paul Tomblin
Paul Tomblin

Reputation: 182880

In any database system I've worked with, there is no harm in doing a rollback right after the commit, so if you commit in the try block, and rollback in the finally, things get committed, whereas if an exception or early return causes the commit to be missed, the rollback will rollback the transaction. So the safe thing to do is

try {
    conn.setAutoCommit(false);
    ResultSet rs = executeQuery(conn, ...);
    ....
    executeNonQuery(conn, ...);
    ....

    conn.commit();
} finally {
   conn.rollback();
   conn.close();
}

Upvotes: 12

Mr. Shiny and New 安宇
Mr. Shiny and New 安宇

Reputation: 13898

Oracle's JDBC driver commits on close() by default. You should not rely on this behaviour if you intend to write multi-platform JDBC code.

Upvotes: 7

Joel
Joel

Reputation: 3483

According to the javadoc, you should try to either commit or roll back before calling the close method. The results otherwise are implementation-defined.

Upvotes: 31

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