Extending a FeatureCollection by Adding new Attributes

The Problem

I imported a shapefile and put its contents in a jump FeatureCollection. With these Features I’m doing some calculations and now I want to add the result as a new attribute to the features, so I can export it as a new shapefile.

So basically I want to add a new field to attribute table and fill it with values.

But I just can’t figure it out! I played with with the addAttribute Method of the FeatureSchema, but that didn’t really work.

The Solution

you need to do the following:

• create a new FeatureSchema based on the old one
• create a new FeatureDataset with that FeatureSchema
• copy every feature from old to new FeatureSchema (use the function FeatureCollectionTools.copyFeatureAndSetFeatureSchema for this)
• add the features to the new FeatureSchema
• display

a code example can be found below

Another option, with respect to updating, may be to look on how the "View / Edit Schema"-Function from the mouse menu works (class: com.vividsolutions.jump.workbench.ui.plugin.ViewSchemaPlugIn)

Example

• the input is pFeatures
• I assume that this code is in the "run" or "execute" method of a plugin.

FeatureSchema fsNew=(FeatureSchema)pFeatures.getFeatureSchema().clone();
fsNew.addAttribute("huhuattribut",AttributeType.STRING);
resultFC = new FeatureDataset(fsNew);
//-- set the attribute for every feature in the collection
for (Iterator iterator = pFeatures.iterator(); iterator.hasNext();) {
    Feature ftemp = (Feature) iterator.next();
    //-- copies the original feature to the new feature schema
    Feature fcore = FeatureCollectionTools.copyFeatureAndSetFeatureSchema(ftemp, fsNew);
    //-- in case the geometry changed:
    fcore.setGeometry(core);
    //-- set the new attribute           
    fcore.setAttribute("huhuattribut", "helloworld");
    resultFC.add(fcore);
}
//-- display
context.addLayer(StandardCategoryNames.RESULT, "newLayer", resultFC);