Details
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Type:
New Feature
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Status:
Closed
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Resolution: Fixed
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Affects Version/s: None
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Fix Version/s: 1.3
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Component/s: None
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Labels:None
Description
A huge number of PropertyEditors has been created and you could help the usage of these through adding a SingleValueConverter that utilizes a PropertyEditor. A Simple version that we've used is like this:
import java.beans.PropertyEditor;
import com.thoughtworks.xstream.converters.SingleValueConverter;
public class PropertyEditorValueConverter implements SingleValueConverter {
final private PropertyEditor editor;
final private Class type;
public PropertyEditorValueConverter(PropertyEditor editor, Class type)
{ this.editor = editor; this.type = type; }public Object fromString(String str)
{ editor.setAsText(str); return editor.getValue(); }public String toString(Object obj)
{ editor.setValue(obj); return editor.getAsText(); }public boolean canConvert(Class type)
{ return this.type.isAssignableFrom(type); }}
Here's a test case:
import java.awt.Color;
import junit.framework.TestCase;
import sun.beans.editors.ColorEditor;
public class PropertyEditorValueConverterTest extends TestCase {
PropertyEditorValueConverter converter = new PropertyEditorValueConverter(new ColorEditor(), Color.class);
public void testMatchesClass() throws Exception
{ assertTrue(converter.canConvert(Color.class)); assertFalse(converter.canConvert(Object.class)); }public void testConverting() throws Exception
{ assertConvertWorks(Color.black); assertConvertWorks(Color.blue); assertConvertWorks(Color.yellow); }private void assertConvertWorks(Color testObject)
{ String string = converter.toString(testObject); assertEquals(testObject, converter.fromString(string)); }}
Activity
Looks interesting. Might be enough if you sync on the editor instance in the two serialization methods. Depends on the use case. An alternative approach would be a pool of those editors like it is done in the ThreadSafeSimpleDateFormat class in c.t.x.core.util ...
Jörg Schaible
added a comment - Looks interesting. Might be enough if you sync on the editor instance in the two serialization methods. Depends on the use case. An alternative approach would be a pool of those editors like it is done in the ThreadSafeSimpleDateFormat class in c.t.x.core.util ... Yes, synchronizing should be enough. here's a version where editor is instantiated for each case. All editors have empty constructors (as per class conctract) so should work nicely.
public class PropertyEditorValueConverter implements SingleValueConverter {
final private Class<? extends PropertyEditor> editorType;
final private Class convertedType;
public PropertyEditorValueConverter(Class<? extends PropertyEditor> editorType, Class type)
{ this.editorType = editorType; this.convertedType = type; }public Object fromString(String str)
{ PropertyEditor editor2 = createEditor(); editor2.setAsText(str); return editor2.getValue(); }public String toString(Object obj)
{ PropertyEditor editor2 = createEditor(); editor2.setValue(obj); return editor2.getAsText(); }public boolean canConvert(Class type)
{ return this.convertedType.isAssignableFrom(type); } private PropertyEditor createEditor() {
try
catch (Exception e)
{ throw new RuntimeException(e); } }
}
Jukka Lindström
added a comment - Yes, synchronizing should be enough. here's a version where editor is instantiated for each case. All editors have empty constructors (as per class conctract) so should work nicely.
public class PropertyEditorValueConverter implements SingleValueConverter {
final private Class<? extends PropertyEditor> editorType;
final private Class convertedType;
public PropertyEditorValueConverter(Class<? extends PropertyEditor> editorType, Class type)
{
this.editorType = editorType;
this.convertedType = type;
}
public Object fromString(String str)
{
PropertyEditor editor2 = createEditor();
editor2.setAsText(str);
return editor2.getValue();
}
public String toString(Object obj)
{
PropertyEditor editor2 = createEditor();
editor2.setValue(obj);
return editor2.getAsText();
}
public boolean canConvert(Class type)
{
return this.convertedType.isAssignableFrom(type);
}
private PropertyEditor createEditor() {
try
{
return editorType.newInstance();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
} Hello Jukka, I've added a thread-safe version for this to the head revision. You may try this out yourself. Thanks a lot!
Jörg Schaible
added a comment - Hello Jukka, I've added a thread-safe version for this to the head revision. You may try this out yourself. Thanks a lot! Closing issues before next release.
Jörg Schaible
added a comment - Closing issues before next release. 
Just after commiting this I remembered that property editors are not thread safe.. I'll commit a thread safe version tomorrow (where the constructor argument is class for the property editor and the fromString / toString methods instantiate the class.