Java tutorial
/* * Databinder: a simple bridge from Wicket to Hibernate * Copyright (C) 2007 Nathan Hamblen nathan@technically.us * Copyright (C) 2007 xoocode.org project * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ package net.databinder.components.hib; import java.io.Serializable; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import net.databinder.hib.Databinder; import net.databinder.models.hib.HibernateObjectModel; import org.apache.wicket.Component; import org.apache.wicket.ajax.AjaxRequestTarget; import org.apache.wicket.ajax.markup.html.form.AjaxButton; import org.apache.wicket.extensions.markup.html.repeater.data.table.AbstractColumn; import org.apache.wicket.extensions.markup.html.repeater.data.table.DataTable; import org.apache.wicket.extensions.markup.html.repeater.data.table.HeadersToolbar; import org.apache.wicket.extensions.markup.html.repeater.data.table.IColumn; import org.apache.wicket.extensions.markup.html.repeater.data.table.NavigationToolbar; import org.apache.wicket.extensions.markup.html.repeater.data.table.PropertyColumn; import org.apache.wicket.markup.html.WebMarkupContainer; import org.apache.wicket.markup.html.basic.Label; import org.apache.wicket.markup.html.form.Form; import org.apache.wicket.markup.html.form.TextArea; import org.apache.wicket.markup.html.panel.Panel; import org.apache.wicket.markup.repeater.Item; import org.apache.wicket.markup.repeater.data.IDataProvider; import org.apache.wicket.model.BoundCompoundPropertyModel; import org.apache.wicket.model.CompoundPropertyModel; import org.apache.wicket.model.IModel; import org.apache.wicket.model.Model; import org.apache.wicket.model.PropertyModel; import org.apache.wicket.util.string.Strings; import org.hibernate.Query; import org.hibernate.QueryException; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.metadata.ClassMetadata; import org.hibernate.type.Type; /** * A Panel used to display a textarea to enter an HQL query and execute it * against the current session of a {@link SessionFactory}. * <p> * The panel result is displayed in a data table, where columns are created * according to the query. * <p> * For instance, a query like: * <pre> * select job.name as name, job.id as id from JobModel job * </pre> * will result in two columns, 'name' and 'id', in the result data table. * <p> * If you run: * <pre> * from JobModel * </pre> * the columns in the result table will be the available properties of a * JobModel */ public class QueryPanel extends Panel { private static final long serialVersionUID = 1L; /** * Bean used to store the query */ private QueryBean query = new QueryBean(); /** * Stores information about the query execution (executed query, time, ...) */ private String executionInfo; /** * Constructs an {@link QueryPanel} * @param id * the panel identifier. Must not be null. */ public QueryPanel(String id) { super(id); final WebMarkupContainer resultsHolder = new WebMarkupContainer("resultsHolder"); resultsHolder.add(new Label("executionInfo", new PropertyModel(this, "executionInfo"))); resultsHolder.add(getResultsTable()); resultsHolder.setOutputMarkupId(true); add(resultsHolder); Form form = new Form("form", new CompoundPropertyModel(query)); form.setOutputMarkupId(true); form.add(new TextArea("query")); form.add(new AjaxButton("submit", form) { private static final long serialVersionUID = 1L; protected void onSubmit(AjaxRequestTarget target, Form form) { if (resultsHolder.get("results") != null) { resultsHolder.remove("results"); } try { resultsHolder.add(getResultsTable()); } catch (QueryException e) { note(e); } catch (IllegalArgumentException e) { note(e); } catch (IllegalStateException e) { note(e); } target.addComponent(resultsHolder); } private void note(Exception e) { resultsHolder.add(new Label("results", e.getClass().getSimpleName() + ": " + e.getMessage())); } }); add(form); } /** * Creates a result table for the current query. * @return a result table, or an empty label if there is no current query */ private Component getResultsTable() { if (Strings.isEmpty(query.getQuery())) { return new Label("results", ""); } else { IDataProvider dataProvider = new IDataProvider() { private static final long serialVersionUID = 1L; public void detach() { } public int size() { Session sess = Databinder.getHibernateSession(); Query query = sess.createQuery(getQuery()); return query.list().size(); } public String getQuery() { return QueryPanel.this.query.getQuery(); } public IModel model(Object object) { return new BoundCompoundPropertyModel(new HibernateObjectModel(object)); } public Iterator iterator(int first, int count) { Session sess = Databinder.getHibernateSession(); long start = System.nanoTime(); try { Query q = sess.createQuery(getQuery()); q.setFirstResult(first); q.setMaxResults(count); return q.iterate(); } finally { float nanoTime = ((System.nanoTime() - start) / 1000) / 1000.0f; setExecutionInfo("query executed in " + nanoTime + " ms: " + getQuery()); } } }; IColumn[] columns; Session sess = Databinder.getHibernateSession(); Query q = sess.createQuery(query.getQuery()); String[] aliases; Type[] returnTypes; try { aliases = q.getReturnAliases(); returnTypes = q.getReturnTypes(); } catch (NullPointerException e) { // thrown on updates return new Label("results", ""); } if (returnTypes.length != 1) { columns = new IColumn[returnTypes.length]; for (int i = 0; i < returnTypes.length; i++) { String alias = aliases == null || aliases.length <= i ? returnTypes[i].getName() : aliases[i]; final int index = i; columns[i] = new AbstractColumn(new Model(alias)) { private static final long serialVersionUID = 1L; public void populateItem(Item cellItem, String componentId, IModel rowModel) { Object[] objects = (Object[]) rowModel.getObject(); cellItem.add(new Label(componentId, new Model(objects[index] == null ? "" : objects[index].toString()))); } }; } } else { Type returnType = returnTypes[0]; if (returnType.isEntityType()) { Class clss = returnType.getReturnedClass(); ClassMetadata metadata = Databinder.getHibernateSessionFactory().getClassMetadata(clss); List<IColumn> cols = new ArrayList<IColumn>(); String idProp = metadata.getIdentifierPropertyName(); cols.add(new PropertyColumn(new Model(idProp), idProp)); String[] properties = metadata.getPropertyNames(); for (String prop : properties) { Type type = metadata.getPropertyType(prop); if (type.isCollectionType()) { // TODO: see if we could provide a link to the collection value } else { cols.add(new PropertyColumn(new Model(prop), prop)); } } columns = (IColumn[]) cols.toArray(new IColumn[cols.size()]); } else { String alias = aliases == null || aliases.length == 0 ? returnType.getName() : aliases[0]; columns = new IColumn[] { new AbstractColumn(new Model(alias)) { private static final long serialVersionUID = 1L; public void populateItem(Item cellItem, String componentId, IModel rowModel) { cellItem.add(new Label(componentId, rowModel)); } } }; } } DataTable dataTable = new DataTable("results", columns, dataProvider, 10); dataTable.addTopToolbar(new HeadersToolbar(dataTable, null)); dataTable.addBottomToolbar(new NavigationToolbar(dataTable)); dataTable.setOutputMarkupId(true); return dataTable; } } private static class QueryBean implements Serializable { private static final long serialVersionUID = 1L; private String query; public String getQuery() { return query; } public void setQuery(String query) { this.query = query; } } public String getExecutionInfo() { return executionInfo; } public void setExecutionInfo(String executionInfo) { this.executionInfo = executionInfo; } }