Affected Version
Latest master version.
Description
According to the JDBC 4.1 Spec, a JDBC Statement is closed when:
An application calls the method Statement.close to indicate that it has finished processing a statement. All Statement objects will be closed when the connection that created them is closed.
This means that, if a statement encounters an exception, we can close the ResultSet associated with a statement, but not the statement itself. Yet, Druid explicitly closes statements on errors. Consider this test in DruidAvaticaHandlerTest:
@Test
public void testNotTooManyStatementsWhenTheyThrowErrors() throws Exception
{
for (int i = 0; i < 50; i++) {
Exception thrown = null;
try {
client.createStatement().executeQuery("SELECT SUM(nonexistent) FROM druid.foo");
}
catch (Exception e) {
thrown = e;
}
Assert.assertNotNull(thrown);
}
}The only way the above could work is if executeQuery() closes the statement, which it should not do. The failure can close the associated ResultSet.
The test should be coded as:
@Test
public void testNotTooManyStatementsWhenClosed() throws Exception
{
for (int i = 0; i < 50; i++) {
Exception thrown = null;
try (Statement statement = client.createStatement()) {
statement.executeQuery("SELECT SUM(nonexistent) FROM druid.foo");
}
catch (Exception e) {
thrown = e;
}
Assert.assertNotNull(thrown);
}
}Solution
This issue is fixed in PR #12636.
Affected Version
Latest
masterversion.Description
According to the JDBC 4.1 Spec, a JDBC
Statementis closed when:This means that, if a statement encounters an exception, we can close the
ResultSetassociated with a statement, but not the statement itself. Yet, Druid explicitly closes statements on errors. Consider this test inDruidAvaticaHandlerTest:The only way the above could work is if
executeQuery()closes the statement, which it should not do. The failure can close the associatedResultSet.The test should be coded as:
Solution
This issue is fixed in PR #12636.