10 Человеко-лет GWT

Кирпиченков Денис / @dkirpichenkov

Web frameworks. v2009

GWT or not GWT

Java everywhere

Every browser rocks

Fast & Furious

"I show you how deep the rabbit hole goes"

GWT App Architecture

Google Gin

• AbstractGinModule

  public class AGinModule 
  extends AbstractGinModule {
    @Override
    protected void configure() {
      bind(EventBus.class)
      .to(SimpleEventBus.class).in(Singleton.class);  	
    }
  }
  

• Injector

  @GinModules({AGinModule.class})
  public interface HelloGinjector extends Ginjector {      
    EventBus getEventBus();
  }
  

• @Inject everywhere

  @javax.inject.Inject
  EventBus bus;
  

Publish/Subscriber

MVP

All together

RPC Services

• Client Interface

  @RemoteServiceRelativePath("greet")
  public interface GreetingService extends RemoteService {       
    String greetServer(String name);
  }

• Internal Interface

  public interface GreetingServiceAsync {      
     void greetServer(String name, AsyncCallback<String> callback);			
  }

• Server-side implementation

  public class GreetingServiceImpl extends RemoteServiceServlet 
  	implements GreetingService {
    public String greetServer(String input)					
  }
  

Server Side. GWT WAY

Command in action

GWT PRC is about serialization

GWT RPC Payload

Request:

Response:

Альтернативы

• RequestBuilder + JSON
• REST. https://resty-gwt.github.io/
• Apache Thrift. https://thrift.apache.org/

Thrift request

Thrift response

GWT модули

app.gwt.xml

GWT модули

app.gwt.xml

GWT модули

app.gwt.xml

GWT ⇋ Javascript

• Вызов JS

  public static native void alert(String msg) /*-{
    $wnd.alert(msg);
  }-*/;

• Вызов GWT кода из JS

  public MyUtilityClass{ 
    public static int computeLoanInterest(int amt, 	
  	float interestRate, int term)
    {
    } 
  
    public static native void exportStaticMethod() 	
    /*-{ 
      $wnd.computeLoanInterest = 
      $entry(@mypackage.MyUtilityClass::computeLoanInterest(IFI));		
      }-*/;
    }

Build process

GWT Debugging

Super Dev Mode Debug

Super Dev Mode Debug cont.

When something went wrong

Обработка unhandled exception

public class Example implements EntryPoint {
 public void onModuleLoad() {
   GWT.setUncaughtExceptionHandler(new 
   		GWT.UncaughtExceptionHandler(){			
     	  	   public void onUncaughtException(Throwable e)
     	  	   {
     	  	      // Обработка исключения
     	  	      // Вывод в консоль браузера
     	  	      // Отправка на сервер для записи в Log
     	  	   }
   });
 }
}

Как выглядит исключение

Разбор исключения

Получение stack'а ошибки

SymbolMaps

├── rpcPolicyManifest
│   ├── manifests
│   │   ├── 00B81EDF1ED878A9499F77A6BD72F97F.txt
│   │   ├── 27129259FF55ECBA1F313FA0BADCBA06.txt
│   │   └── CC6E72C03242CD463A2772C4EB4319A3.txt
│   └── manifest.txt
└── symbolMaps
    ├── 13210C7473C45016FBFC764429C5C72E.symbolMap
    ├── 3E4B428A471EFD1DC803630D26A049E0.symbolMap
    ├── 404EF130736C6AC4DE2BD3A75256BD93.symbolMap
    ├── 62BE5A8854B6B01F24C28CAAF8042C17.symbolMap
    ├── 748D3FC843595E743A328BC78E15A9C1.symbolMap
    ├── 8ADFAB542FFF497459382D8182742EC4.symbolMap
    ├── 8DD9F56074FF19AFDD37F4A9273CC6F6.symbolMap
    ├── 9770311386402AEAA5B61BFAF6D8B0BD.symbolMap
    ├── C4F82D4876541A04B1F97B261F3D6517.symbolMap
    └── D6682ADEC5C101DDB41DDA2392DBD6AF.symbolMap

Более понятный Stack

Vaadin Errai

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