sample simple-framework, repeated elements

SkipDoubleElements.java

import java.util.ArrayList;

import org.simpleframework.xml.*;
import org.simpleframework.xml.core.Persister;

public class SkipDoubleElements {

	static class RepeatElements {

		@ElementListUnion({ @ElementList(entry = "enable", type = Boolean.class, inline = true) })
		private ArrayList<Boolean> enables = new ArrayList<>();

		public boolean isEnabled() {
			// TODO check size
			return enables.get(0).booleanValue();
		}

		public RepeatElements() {
			enables.add(Boolean.valueOf(true));
			enables.add(Boolean.valueOf(true));
			enables.add(Boolean.valueOf(true));
		}

	}

	@Root(strict = false)
	static class RepeatElements2 {

		@Element(required = false)
		protected boolean enable = true;

		@Override
		public String toString() {
			return "RepeatElements2 [enable=" + enable + "]";
		}

	}

	public static void main(String[] args) {
		Serializer serializer = new Persister();

		String repeat2Inavlid =
				"<repeatElements2>" +
						"<enable>true</enable>" +
						"<enable>true</enable>" +
						"<enable>true</enable>" +
				"</repeatElements2>";

		String repeat2Valid =
				"<repeatElements2>" +
						"<enable>false</enable>" +
				"</repeatElements2>";

		String repeat2Valid0 =
				"<repeatElements2>" +
				"</repeatElements2>";

		try {
			serializer.write(new RepeatElements(), System.out);

			RepeatElements2 vaildRepeat = serializer.read(RepeatElements2.class, repeat2Valid);
			System.out.println("\n" + vaildRepeat);

			RepeatElements2 vaildRepeat0 = serializer.read(RepeatElements2.class, repeat2Valid0);
			System.out.println("\n" + vaildRepeat0);
			
			// throws an Exception
			RepeatElements2 inVaildRepeat = serializer.read(RepeatElements2.class, repeat2Inavlid);
			System.out.println("\n" + inVaildRepeat);
		}
		catch (Exception e) {
			e.printStackTrace();
		}
	}
}