wicket-examples/src/java/guestbook2/Home.java

/*
 * $Id$
 * $Revision$
 * $Date$
 *
 * ====================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package guestbook2;

import com.voicetribe.wicket.PageParameters;
import com.voicetribe.wicket.RequestCycle;
import com.voicetribe.wicket.markup.html.HtmlPage;
import com.voicetribe.wicket.markup.html.basic.Label;
import com.voicetribe.wicket.markup.html.basic.MultiLineLabel;
import com.voicetribe.wicket.markup.html.form.Form;
import com.voicetribe.wicket.markup.html.form.TextArea;
import com.voicetribe.wicket.markup.html.table.Cell;
import com.voicetribe.wicket.markup.html.table.Table;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.MappingException;
import net.sf.hibernate.Session;
import net.sf.hibernate.Transaction;

import nl.openedge.util.hibernate.HibernateHelper;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * A simple "guest book" example that allows visitors to the page to add a comment
 * and see the comments others have added.
 * @author Jonathan Locke
 */
public class Home extends HtmlPage
{
    // A global list of all comments from all users
    private static final List commentList = new ArrayList();

    static
    {
        try
        {
            try
            {
                new DBUtil().initDB("/hibernate.cfg.xml");
            }
            catch (Exception e1)
            {
                e1.printStackTrace();
            }

            // Get hibernate session
            Session session = HibernateHelper.getSession();

            try
            {
                // Save comment to db
                commentList.clear();
                commentList.addAll(session.find(
                        "from comment in class guestbook2.Comment "
                        + "order by comment.date desc"));
            }
            finally
            {
                HibernateHelper.closeSession();
            }
        }
        catch (MappingException e)
        {
            e.printStackTrace();
        }
        catch (HibernateException e)
        {
            e.printStackTrace();
        }
    }

    // The table of comments shown on this page
    private final Table table;

    /**
     * Constructor that is invoked when page is invoked without a session.
     * @param parameters Page parameters
     */
    public Home(final PageParameters parameters)
    {
        // Add comment form
        add(new CommentForm("commentForm"));

        // Add table of existing comments
        add(table = new Table("comments", commentList)
                {
                    public void populateCell(final Cell cell)
                    {
                        final Comment comment = (Comment) cell.getModelObject();

                        cell.add(new Label("date", comment.getDate()));
                        cell.add(new MultiLineLabel("text", comment.getText()));
                    }
                });
    }

    /**
     * A form that allows a user to add a comment.
     * @author Jonathan Locke
     */
    public final class CommentForm extends Form
    {
        // The comment that this form is editing
        private final Comment comment = new Comment();

        /**
         * Constructor.
         * @param componentName The name of this component
         */
        public CommentForm(final String componentName)
        {
            // Construct form with no validation listener
            super(componentName, null);

            // Add text entry widget
            add(new TextArea("text", comment, "text"));
        }

        /**
         * Show the resulting valid edit.
         * @param cycle The request cycle
         */
        public final void handleSubmit(final RequestCycle cycle)
        {
            // Construct a copy of the edited comment
            final Comment newComment = new Comment(comment);

            // Set date of comment to add
            newComment.setDate(new Date());

            // Add the component we edited to the list of comments
            commentList.add(newComment);

            try
            {
                // Get hibernate session
                Session session = HibernateHelper.getSession();

                try
                {
                    // Save comment to db
                    Transaction transaction = session.beginTransaction();

                    session.save(newComment);
                    transaction.commit();
                }
                finally
                {
                    HibernateHelper.closeSession();
                }
            }
            catch (MappingException e)
            {
                throw new RuntimeException("Unable to map hibernate object", e);
            }
            catch (HibernateException e)
            {
                throw new RuntimeException("Unable to save comment", e);
            }

            table.invalidateModel();
        }
    }
}

///////////////////////////////// End of File /////////////////////////////////