spring annotation-based configuration - memory consumption too high?

Question

As I noticed crazy high RAM usage on my client application (Swing-based), I started looking into it and it seems like this is somehow related to Annotation-based configuration in Spring. As you will see in my edits below, i realized that this occurs only on 64-Bit JVM. See the following testcode: xml-based configuration ``` public class XmlConfigTest extends JFrame { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("config/applicationContext.xml"); XmlConfigTest frame = (XmlConfigTest) ctx.getBean("xmlConfigTest"); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); frame.setVisible(true); } } ``` Uses up about 32MB memory, which seems ok to me. Now the same with annotation based configuration: ``` @Service public class AnnotationConfigTestFrame extends JFrame { public static void main(String[] args) throws InterruptedException { ApplicationContext ctx = new A…

Accepted Answer

At startup a large number of `java.lang.reflect.Method` objects are created.

These objects are eligible for garbage collection, but in the case of your application it probably causes too many eden collections which results in high startup times.

Most of these `java.lang.reflect.Method` objects are allocated at the following site:

These seem to be created when Spring tries to find setters on `AnnotationConfigTestFrame` which inherits lots of methods from `java.awt` and `javax.swing` super classes. I did not read through the relevant code closely, but as a quick test to verify this hypothesis, I did the following:

```
@Service
public class AnnotationConfigTestFrame /* extends JFrame */
{
    public static void main(String[] args) throws InterruptedException
    {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(AnnotationConfigTestFrame.class);

AnnotationConfigTestFrame frame = (AnnotationConfigTestFrame) ctx
                .getBean("annotationConfigTestFrame");
//        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
//        frame.setVisible(true);

waitABit();
        printRuntimeStats();
        System.exit(0);
    }
}
```

i.e. made `AnnotationConfigTestFrame` not inherit from `javax.swing.JFrame`. Now the memory usage for looking up the bean is reasonably low!

This might give you hints for debugging this further.

spring annotation-based configuration - memory consumption too high?

Solution

Problem