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POHTTPSession with GWT
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copied!<p>I'm new in GWT ... I would like to implement sessions in my Web App Basically I want that a session starts at the click of a button (handle an event) and ends at the click of another button (other handle an event). It's possible?</p> <p>How to do it step by step?</p> <p>Is it okay this code?:</p> <p><strong>Main (client-side):</strong></p> <pre><code>Button b1 = new Button("b1"); b1.addClickHandler(new ClickHandler) { public voin onClick(){ ... rpc.setSession(callback); //rpc call the service... } } Button b2 = new Button("b2"); b1.addClickHandler(new ClickHandler) { public voin onClick(){ ... rpc.exitSession(callback); } } </code></pre> <p>//------------------------------------------------------------------------------------</p> <pre><code>import com.google.gwt.user.client.rpc.RemoteService; public interface MySession extends RemoteService { public void setSession(); public void exitSession(); } </code></pre> <p>//------------------------------------------------------------------------------------</p> <pre><code>import com.google.gwt.user.client.rpc.AsyncCallback; public interface MySessionAsync { void setSession(AsyncCallback<Void> callback); void exitSession(AsyncCallback<Void> callback); } </code></pre> <p>//------------------------------------------------------------------------------------</p> <pre><code>import de.vogella.gwt.helloworld.client.MySession; public class MySessionImpl extends RemoteServiceServlet implements MySession { HttpSession httpSession; @Override public void setSession() { httpSession = getThreadLocalRequest().getSession(); httpSession = this.getThreadLocalRequest().getSession(); httpSession.setAttribute("b", "1"); } @Override public void exitSession() { httpSession = this.getThreadLocalRequest().getSession(); httpSession.invalidate(); // kill session } } </code></pre> <p>What I do is I connect with my Web application to another web page, if I click the back button of the browser that I return to my web app with the session still alive ... How can I do?</p> <p>I hope I have explained well what my problem ...</p> <p>*****NEW PROBLEM***:**</p> <p>I tried to do so ...</p> <p><strong>---client side.... MAIN:</strong></p> <pre><code> MyServiceAsync service = (MyServiceAsync) GWT.create(MyService.class); ServiceDefTarget serviceDef = (ServiceDefTarget) service; serviceDef.setServiceEntryPoint(GWT.getModuleBaseURL()+ "rpc"); boolean b=false;; b=service.checkSession(new AsyncCallback<Boolean>() { @Override public void onSuccess(Boolean result) { // here is the result if(result){ // yes the attribute was setted } } @Override public void onFailure(Throwable caught) { Window.alert(caught.getMessage()); } }); if (b==false){ // se non esiste una sessione RootPanel.get().add(verticalPanel); RootPanel.get().add(etichetta); RootPanel.get().add(nameField); RootPanel.get().add(sendButton); RootPanel.get().add(horizontalPanel); } else{ //esiste già una sessione attiva (pagina da loggato) welcome.setText("Ciao "+userCorrect+"!!"); RootPanel.get().add(verticalPanelLog); RootPanel.get().add(etichetta); RootPanel.get().add(nameField); RootPanel.get().add(cercaLog); RootPanel.get().add(horizontalPanel); } </code></pre> <p>////////////////////////////////////////////////////////////////////////</p> <pre><code>public interface MyServiceAsync { ... void exitSession(AsyncCallback<Void> callback); void setSession(AsyncCallback<Void> callback); void checkSession(AsyncCallback<Boolean> callback); //error!! </code></pre> <p>////////////////////////////////////////////////////////////////////////</p> <pre><code>public interface MyService extends RemoteService { /..... public void setSession(); public void exitSession(); public boolean checkSession(); </code></pre> <p>////////////////////////////////////////////////////////////////////////</p> <p><strong>server-side:</strong></p> <pre><code>public boolean checkSession() { httpSession = this.getThreadLocalRequest().getSession(); //se la sessione esiste già if (httpSession.getAttribute("b")!= null){ return true; } else{ . return false; } </code></pre>

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