Guice 简明教程

Google Guice - Constructor Injection

注入是向对象中注入依赖项的过程。构造函数注入非常普遍。在此过程中，依赖项以参数的形式注入到构造函数中。请参阅以下示例。

Injection is a process of injecting dependeny into an object. Constructor injection is quite common. In this process, dependency is injected as argument to the constructor. See the example below.

创建名为 GuiceTester 的 Java 类。

Create a java class named GuiceTester.

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。

Compile and run the file, you will see the following output.

Inside checkSpelling.