Java tutorial
/* * Copyright 2008 Jeff Dwyer * * 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 com.apress.progwt.client; import com.allen_sauer.gwt.log.client.Log; import com.apress.progwt.client.college.LoginService; import com.apress.progwt.client.college.ServiceCache; import com.apress.progwt.client.college.gui.status.StatusPanel; import com.apress.progwt.client.consts.ConstHolder; import com.apress.progwt.client.consts.images.Images; import com.apress.progwt.client.rpc.StdAsyncCallback; import com.apress.progwt.client.service.remote.GWTSchoolService; import com.apress.progwt.client.service.remote.GWTSchoolServiceAsync; import com.apress.progwt.client.service.remote.GWTUserService; import com.apress.progwt.client.service.remote.GWTUserServiceAsync; import com.google.gwt.core.client.GWT; import com.google.gwt.gears.core.client.GearsException; import com.google.gwt.gears.localserver.client.LocalServer; import com.google.gwt.gears.localserver.client.ManagedResourceStore; import com.google.gwt.i18n.client.Dictionary; import com.google.gwt.user.client.Timer; import com.google.gwt.user.client.rpc.SerializationException; import com.google.gwt.user.client.rpc.ServiceDefTarget; import com.google.gwt.user.client.rpc.impl.ClientSerializationStreamReader; import com.google.gwt.user.client.rpc.impl.RemoteServiceProxy; import com.google.gwt.user.client.ui.Label; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Widget; public class GWTApp { private static final String MANIFEST_URL = "manifest.json"; private static String getLoadID(int id) { return "gwt-slot-" + id; } private static String getPreLoadID(int id) { return "gwt-loading-" + id; } public static void show(int id, Widget panel) { RootPanel.get(getPreLoadID(id)).setVisible(false); RootPanel.get(getLoadID(id)).add(panel); } private LoginService loginService; private int pageID; private GWTSchoolServiceAsync schoolService; private ServiceCache serviceCache; private GWTUserServiceAsync userService; public GWTApp(int pageID) { this.pageID = pageID; // setup the StatusPanel. There will be just one DIV for this, no // matter how many apps we have in the same page. try { RootPanel status = RootPanel.get("gwt-status"); if (status.getWidgetCount() == 0) { StatusPanel sp = new StatusPanel(); status.add(sp); StdAsyncCallback.setManager(sp); } } catch (Exception e) { Log.error("Status Panel problem: "); } // create the Local Server after enough of a delay so that we try // to appear as lightweight as possible. new Timer() { @Override public void run() { try { doLocalServer(); } catch (Exception e) { Log.warn("LocalServer exception: " + e); } } }.schedule(10000); } public Object deserialize(String serialized) { ClientSerializationStreamReader c; Log.debug("Try to deserialize: " + serialized); try { c = getBootstrapService().createStreamReader(serialized); Object o = c.readObject(); return o; } catch (SerializationException e) { throw new RuntimeException(e); } } private void doLocalServer() throws GearsException { LocalServer localServer = new LocalServer(); final ManagedResourceStore managedResourceStore = localServer.createManagedResourceStore("ToCollege.net"); try { managedResourceStore.setManifestURL(Interactive.getRelativeURL(MANIFEST_URL)); } catch (Exception e) { // expected in hosted mode. catches JS exception from setting // 8080 when running on 8888 throw new GearsException(e.getMessage()); } new Timer() { public void run() { switch (managedResourceStore.getUpdateStatus()) { case ManagedResourceStore.UPDATE_OK: Log.info("UPDATE_OK " + managedResourceStore.getCurrentVersion()); cancel(); break; case ManagedResourceStore.UPDATE_CHECKING: Log.debug("Checking " + managedResourceStore.getCurrentVersion()); break; case ManagedResourceStore.UPDATE_DOWNLOADING: Log.debug("Downloading " + managedResourceStore.getCurrentVersion()); break; case ManagedResourceStore.UPDATE_FAILED: Log.warn("Fail " + managedResourceStore.getCurrentVersion()); Log.warn(managedResourceStore.getLastErrorMessage()); cancel(); break; } } }.scheduleRepeating(2000); managedResourceStore.checkForUpdate(); } /** * get the Object that has been serialized under the JavaScript var * name "serialized" * * @return */ protected Object getBootstrapped() { return getBootstrapped("serialized"); } /** * * Remember, the RemoteServiceProxy that you use must have a method * that returns the type that you wish to serialize. Otherwise, the * deserializer will not be created. * * Cast the service into a RemoteServiceProxy, grab the stream reader * and deserialize. * * @param name * @return */ private Object getBootstrapped(String name) { String serialized = getParam(name); if (serialized == null) { Log.warn("No param " + name); return null; } try { return deserialize(serialized); } catch (Exception e) { Log.error("Bootstrap " + name + " Problem ", e); return null; } } private RemoteServiceProxy getBootstrapService() { return (RemoteServiceProxy) getSchoolService(); } protected String getLoadID() { return getLoadID(pageID); } public LoginService getLoginService() { return loginService; } protected String getParam(String string) { try { Dictionary dictionary = Dictionary.getDictionary("Vars"); return dictionary.get(string + "_" + pageID); } catch (Exception e) { Log.info("Couldn't find param: " + string); return null; } } protected String getPreLoadID() { return getPreLoadID(pageID); } public GWTSchoolServiceAsync getSchoolService() { return schoolService; } public ServiceCache getServiceCache() { return serviceCache; } public GWTUserServiceAsync getUserService() { return userService; } // this doesn't work. serialization strings are different depending on // which way they go // School s = new School(); // String ser = serialize(s); // School e = (School) deserialize(ser); // // public String serialize(Object o) { // try { // ClientSerializationStreamWriter w = getBootstrapService() // .createStreamWriter(); // w.writeObject(o); // Log.debug("Serialized: " + o + "\nto\n" // + w.toString()); // return w.toString(); // } catch (SerializationException e) { // throw new RuntimeException(e); // } // } protected void initConstants() { if (ConstHolder.images == null) { ConstHolder.images = (Images) GWT.create(Images.class); } } /** * call initServices if your GWTApp would like the asynchronous * services to be setup */ protected void initServices() { schoolService = (GWTSchoolServiceAsync) GWT.create(GWTSchoolService.class); ServiceDefTarget endpoint = (ServiceDefTarget) schoolService; String pre = Interactive.getRelativeURL("service/"); endpoint.setServiceEntryPoint(pre + "schoolService"); userService = (GWTUserServiceAsync) GWT.create(GWTUserService.class); ServiceDefTarget endpointUser = (ServiceDefTarget) userService; endpointUser.setServiceEntryPoint(pre + "userService"); if (schoolService == null || userService == null) { Log.error("Service was null."); } serviceCache = new ServiceCache(this); loginService = new LoginService(serviceCache); } protected void loadError(Exception e) { Log.error("e: " + e); e.printStackTrace(); VerticalPanel panel = new VerticalPanel(); panel.add(new Label("Error")); panel.add(new Label(e.getMessage())); RootPanel.get(getPreLoadID()).setVisible(false); RootPanel.get(getLoadID()).add(panel); } public void setPageID(int pageID) { this.pageID = pageID; } protected void show(Widget panel) { show(pageID, panel); } }