Unable to serialize AtomicBoolean on Java 17
#309
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Java 17 is using a internally derived class? I'll have to investigate... |
No. Just like in Java 11, As I explained in the ticket, serializing this class in current versions of XStream uses reflection, which happens to work on Java 11 but does not work on Java 17 without additional
Thanks! |
| import java.util.concurrent.atomic.AtomicBoolean; | ||
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| /** Converts an {@link AtomicBoolean}. */ | ||
| public class AtomicBooleanConverter implements Converter { |
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You should derive from an AbstractSingleValueConverter here. Only a type with a SingleValueConverter can be used as attribute in XML. Since an AtomicBoolean has a scalar value, it should offer this option. You may even derive from the BooleanConverter.
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As explained in #309 (comment) this cannot be done without breaking compatibility with existing serialized data that was serialized with the reflection-based converter.
| import com.thoughtworks.xstream.io.HierarchicalStreamWriter; | ||
| import java.util.concurrent.atomic.AtomicBoolean; | ||
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| /** Converts an {@link AtomicBoolean}. */ |
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From an XML PoV an AtomicBoolean is not different to a normal Boolean, therefore the AtomicBooleanConverter should use a similar implementation (and represention of the value).
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The problem with that approach is that it would break compatibility with existing serialized data that was serialized with the reflection-based converter.
| public void marshal( | ||
| Object source, HierarchicalStreamWriter writer, MarshallingContext context) { | ||
| final AtomicBoolean atomicBoolean = (AtomicBoolean) source; | ||
| writer.startNode("value"); |
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There is no need to create a nested structure for a scalar value. A SingleValueConverter won't let you do this anyway ;-)
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As explained in #309 (comment) the nested structure exists only to preserve compatibility with existing serialized data that was serialized with the reflection-based converter.
| final AtomicBoolean atomicBoolean = (AtomicBoolean) source; | ||
| writer.startNode("value"); | ||
| context.convertAnother( | ||
| atomicBoolean.get(), new SingleValueConverterWrapper(BooleanConverter.BINARY)); |
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You should never use a SingleValueConverterWrapper in your own code. This wrapper is more or less useful for the XStream facade only and helps to manage SingleValueConverters and Converters in the same lists.
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You should never use a SingleValueConverterWrapper in your own code.
Acknowledged. Thankfully, in this case I am using a SingleValueConverterWrapper in XStream's code, not my own.
| @@ -996,6 +998,7 @@ protected void setupConverters() { | |||
| registerConverter(new JavaMethodConverter(classLoaderReference), PRIORITY_NORMAL); | |||
| registerConverter(new JavaFieldConverter(classLoaderReference), PRIORITY_NORMAL); | |||
| registerConverter(new LambdaConverter(mapper, reflectionProvider, classLoaderReference), PRIORITY_NORMAL); | |||
| registerConverter(new AtomicBooleanConverter(), PRIORITY_NORMAL); | |||
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You should also register an alias "atomic-boolean".
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That doesn't fit with my design, which is to re-implement this functionality without reflection without changing the on-disk format.
| + " <musician>\n" | ||
| + " <name>Miles Davis</name>\n" | ||
| + " <genre>jazz</genre>\n" | ||
| + " <alive>\n" |
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Should be by default:
<alive>true<alive>There was a problem hiding this comment.
As explained in #309 (comment) this cannot be done without breaking compatibility with existing serialized data that was serialized with the reflection-based converter.
| + " <musician>\n" | ||
| + " <name>Wynton Marsalis</name>\n" | ||
| + " <genre>jazz</genre>\n" | ||
| + " <alive>\n" |
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Should be by default:
<alive>false<alive>There was a problem hiding this comment.
As explained in #309 (comment) this cannot be done without breaking compatibility with existing serialized data that was serialized with the reflection-based converter.
This is my first attempt at submitting a pull request to XStream, so please let me know if there is anything different I should be doing. I am not sure if this is the right approach to take, so I am posting this in hopes that someone can point me in a better direction if this is wrong.
This PR fixes #308. I took a wild guess as to how it should be implemented.
With the changes to
xstream/src/java/reverted (i.e., at commit 61e0ead), the new test passes on Java 8 and Java 11 but fails on Java 17.With the changes to
xstream/src/java/present (i.e., at commit commit 36b30be), the new test passes on Java 8, Java 11, and Java 17.