ListSizeTest.java

package jp.skypencil;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.Transaction;

/**
 * sizeが5,000を超えるListを永続化すると
 * java.lang.IllegalArgumentException: Too many indexed properties for entity
 * が生じることを確認するためのコード。
 *
 * @author eller86
 */
public final class ListSizeTest extends HttpServlet {

	private static final long serialVersionUID = 5847665302044277654L;

	@Override
	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
		final int size = Integer.valueOf(req.getParameter("s"));
		DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();

		Transaction tx = datastore.beginTransaction();
		try {
			Entity entity = createEntity(size);
			datastore.put(entity);
			tx.commit();
			resp.getWriter().write(size + " is OK");
		} catch (RuntimeException e) {
			tx.rollback();
			e.printStackTrace(resp.getWriter());
		}
	}

	private Entity createEntity(int size) {
		Entity entity = new Entity("TestKind", Integer.toString(size));
		entity.setProperty("array", createList(size));
		return entity;
	}

	private List<Integer> createList(int size) {
		final List<Integer> result = new ArrayList<Integer>(size);
		for (int i = 0; i < size; ++i) result.add(Integer.valueOf(Integer.MIN_VALUE + i));
		return result;
	}
}