Guice 简明教程

Google Guice - First Application

让我们创建一个基于示例控制台的应用程序，我们会逐步使用 Guice 绑定机制演示依赖项注入。

Step 1: Create Interface

//spell checker interface
interface SpellChecker {
   public void checkSpelling();
}

Step 2: Create Implementation

//spell checker implementation
class SpellCheckerImpl implements SpellChecker {
   @Override
   public void checkSpelling() {
      System.out.println("Inside checkSpelling." );
   }
}

Step 3: Create Bindings Module

//Binding Module
class TextEditorModule extends AbstractModule {
   @Override
   protected void configure() {
      bind(SpellChecker.class).to(SpellCheckerImpl.class);
   }
}

Step 4: Create Class with dependency

class TextEditor {
   private SpellChecker spellChecker;
   @Inject
   public TextEditor(SpellChecker spellChecker) {
      this.spellChecker = spellChecker;
   }
   public void makeSpellCheck(){
      spellChecker.checkSpelling();
   }
}

Step 5: Create Injector

Injector injector = Guice.createInjector(new TextEditorModule());

Step 6: Get Object with dependency fulfilled.

TextEditor editor = injector.getInstance(TextEditor.class);

Step 7: Use the object.

editor.makeSpellCheck();

Complete Example

创建名为 GuiceTester 的 Java 类。

GuiceTester.java

import com.google.inject.AbstractModule;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;

public class GuiceTester {
   public static void main(String[] args) {
      Injector injector = Guice.createInjector(new TextEditorModule());
      TextEditor editor = injector.getInstance(TextEditor.class);
      editor.makeSpellCheck();
   }
}

class TextEditor {
   private SpellChecker spellChecker;

   @Inject
   public TextEditor(SpellChecker spellChecker) {
      this.spellChecker = spellChecker;
   }

   public void makeSpellCheck(){
      spellChecker.checkSpelling();
   }
}

//Binding Module
class TextEditorModule extends AbstractModule {

   @Override
   protected void configure() {
      bind(SpellChecker.class).to(SpellCheckerImpl.class);
   }
}

//spell checker interface
interface SpellChecker {
   public void checkSpelling();
}


//spell checker implementation
class SpellCheckerImpl implements SpellChecker {

   @Override
   public void checkSpelling() {
      System.out.println("Inside checkSpelling." );
   }
}

Output

编译运行该文件，您会看到以下输出内容。

Inside checkSpelling.