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https://issues.apache.org/jira/browse/DBUTILS-145?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Carl Franklin Hall closed DBUTILS-145.
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Resolution: Duplicate
Closing this is a duplicate of DBUTILS-135 where the issue was resolved.
> org.apache.commons.dbutils.BeanProcessor doesn't work in multi-thread
> environment
> ---------------------------------------------------------------------------------
>
> Key: DBUTILS-145
> URL: https://issues.apache.org/jira/browse/DBUTILS-145
> Project: Commons DbUtils
> Issue Type: Bug
> Affects Versions: 1.7
> Environment: Checked on Windows 10 and CentOS 7.5 with Java 8 and
> Java 11.
> Reporter: Jan Jurcik
> Priority: Blocker
> Attachments: test-commons-dbutils-multithread.zip
>
>
> Using of BeanProcessor class with multiple threads fails, even every thread
> has its own instance. Th reason is this part of code:
>
> /**
> * ServiceLoader to find <code>ColumnHandler</code> implementations on the
> classpath. The iterator for this is
> * lazy and each time <code>iterator()</code> is called.
> */
> // FIXME: I think this instantiates new handlers on each iterator() call.
> This might be worth caching upfront.
> private static final ServiceLoader<ColumnHandler> columnHandlers =
> ServiceLoader.load(ColumnHandler.class);
> /**
> * ServiceLoader to find <code>PropertyHandler</code> implementations on the
> classpath. The iterator for this is
> * lazy and each time <code>iterator()</code> is called.
> */
> // FIXME: I think this instantiates new handlers on each iterator() call.
> This might be worth caching upfront.
> private static final ServiceLoader<PropertyHandler> propertyHandlers =
> ServiceLoader.load(PropertyHandler.class);
>
> and then using as Iterable:
>
> for (ColumnHandler handler : columnHandlers) {
> if (handler.match(propType)) {
> retval = handler.apply(rs, index);
> break;
> }
> }
> As per ServiceLoader javadoc, this class is not thread safe:
> [https://docs.oracle.com/javase/8/docs/api/java/util/ServiceLoader.html] and
> using the same instance in multiple threads causes either
> NoSuchElementException or ClassCastException.
> Attached is very simple maven java 8 project (the same happens also in other
> versions of Java), which executes simple query and tries to convert it to
> Java Bean. Run it in multi processor environment to simulate the issue. part
> of the project is also fixed version of the class *FixedBeanProcessor* which
> should work on Java 6+.
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