The best practice and common questions of GWT user framework
The best practice and common questions of GWT user framework
GWT (Google Web Toolkit) is an open source Java framework that is used to build a web -based user interface.It allows developers to write client code in Java language and compile them into high -efficiency and scalable JavaScript code.This article will introduce the best practice and common questions of GWT to help developers better use this powerful framework.
Best Practices:
1. Use MVP design mode: In GWT, the MVP (Model-View-Presenter) design mode is a very common architecture mode.It helps separate business logic and interface code, making the code more testability and maintenance.
The following is a simple MVP example:
// Model
public class UserModel {
private String username;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
// View
public interface UserView {
void setUsername(String username);
}
// Presenter
public class UserPresenter {
private final UserModel model;
private final UserView view;
public UserPresenter(UserModel model, UserView view) {
this.model = model;
this.view = view;
}
public void fetchUser() {
// Get user data from the server
String username = "John Doe";
model.setUsername(username);
view.setUsername(username);
}
}
2. Use DeferredBinding: GWT's DeferredBinding function can generate different code according to different configuration environments.This is very convenient for switching between development and production environments, such as different implementation classes, CSS style tables or pictures.
The following is a simple DeferredBinding example:
Add the following configuration in the .gwt.xml file:
<replace-with class="com.example.client.impl.MyServiceImpl">
<when-type-is class="com.example.client.MyService" />
<any>
<when-property-is name="environment" value="development" />
</any>
</replace-with>
<replace-with class="com.example.client.impl.MyServiceProdImpl">
<when-type-is class="com.example.client.MyService" />
<any>
<when-property-is name="environment" value="production" />
</any>
</replace-with>
Then, choose the appropriate implementation class as needed in the code:
MyService service = GWT.create(MyService.class);
By generating different code during the compilation process, the class can be selected according to the configuration environment.
Frequently Asked Questions:
1. How to deal with the dependence between GWT modules?
-It can use the `Inherits` element specified module in the GWT module descriptor (.gwt.xml file).In this way, you can ensure that the modules that depend on compilation and runtime can be used.
2. How to debug the GWT application?
-It can add `<add-linker name =" xsiframe " />` to enable GWT's Super DEV Mode by adding `add-linker name =" xsiframe ".In this way, you can debug the Java code of the GWT application in the browser.In addition, you can use the browser developer tool (such as Chrome Devtools) to debug the JavaScript code generated.
3. How to deal with internationalization and localization?
-Ad the `Messages` and Constants` interfaces of GWT to handle international string.In this way, the appropriate string can be loaded dynamically according to the user's language environment.
public interface MyMessages extends Messages {
@DefaultMessage("Hello, {0}!")
@Description("Example message")
String helloMessage(String name);
}
Then use these string in the code:
MyMessages messages = GWT.create(MyMessages.class);
String greeting = messages.helloMessage("John");
This article introduces the best practice and common questions of GWT.By following these practices, developers can better use the GWT framework to build an efficient web application.
