XStream gets parent in converter

Question

For a local converter, when sorting by XML, is there a way to access the parent?

I need to collect a marker with elements from a third-party source - using the identifier stored in the parent.

Alas, there seems to be no way to query the path of the object leading to the current object. Or is there?

Answer 1

I found a solution with a little reflaction:

import java.io.InputStream; import java.lang.reflect.Field; import java.util.List; import java.util.Map; import org.junit.Test; import org.springframework.util.ReflectionUtils; import com.thoughtworks.xstream.XStream; import com.thoughtworks.xstream.annotations.XStreamAlias; import com.thoughtworks.xstream.annotations.XStreamAsAttribute; import com.thoughtworks.xstream.converters.Converter; import com.thoughtworks.xstream.converters.MarshallingContext; import com.thoughtworks.xstream.converters.UnmarshallingContext; import com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller; import com.thoughtworks.xstream.io.HierarchicalStreamReader; import com.thoughtworks.xstream.io.HierarchicalStreamWriter; import com.thoughtworks.xstream.io.path.Path; import lombok.Data; public class XStreamGetInfoFromParentTest { @Test public void smokeTest() { InputStream file = XStreamGetInfoFromParentTest.class.getResourceAsStream("XStreamGetInfoFromParentTest.xml"); XStream xStream = new XStream() { @Override public void registerConverter(Converter converter, int priority) { Converter myConverter = new MyConverterWrapper(converter); super.registerConverter(myConverter, priority); } }; xStream.processAnnotations(Papa.class); xStream.processAnnotations(Baby.class); Papa papa = (Papa) xStream.fromXML(file); System.out.println(papa); } public class MyConverterWrapper implements Converter { private Converter converter; private boolean isBabyClass; public MyConverterWrapper(Converter converter) { this.converter = converter; } @Override public boolean canConvert(Class type) { this.isBabyClass = type.equals(Baby.class); return converter.canConvert(type); } @Override public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) { this.converter.marshal(source, writer, context); } @SuppressWarnings({ "unchecked", "rawtypes" }) @Override public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) { if (isBabyClass) { AbstractReferenceUnmarshaller runm = (AbstractReferenceUnmarshaller) context; Field field = ReflectionUtils.findField(AbstractReferenceUnmarshaller.class, "values"); field.setAccessible(true); Map values = (Map) ReflectionUtils.getField(field, runm); values.forEach((key, value) -> { System.out.println(key + " : " + value); }); Papa papa = (Papa) values.get(new Path("/papa")); System.out.println(papa.firstname); } return converter.unmarshal(reader, context); } } @XStreamAlias("papa") @Data public class Papa { @XStreamAsAttribute private String firstname; private int age; private List<Baby> babies; } @XStreamAlias("baby") @Data public class Baby { private String firstname; } } 

XML:

 <?xml version="1.0" encoding="UTF-8"?> <papa firstname="Adam"> <age>33</age> <babies> <baby> <firstname>Eva</firstname> </baby> </babies> </papa>