Google Guice - 方法注入

注入是一個向物件注入依賴項的過程。方法注入用於將值物件作為依賴項設定到該物件。請參見下面的示例。

示例

建立一個名為 GuiceTester 的 Java 類。

import com.google.inject.AbstractModule;
import com.google.inject.Guice;
import com.google.inject.ImplementedBy;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.name.Named;
import com.google.inject.name.Names;

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(String.class)
         .annotatedWith(Names.named("JDBC"))
         .toInstance("jdbc:mysql://:5326/emp");
   } 
}

@ImplementedBy(SpellCheckerImpl.class)
interface SpellChecker {
   public void checkSpelling();
}

//spell checker implementation
class SpellCheckerImpl implements SpellChecker {
 
   private String dbUrl;

   public SpellCheckerImpl(){}
   
   @Inject 
   public void setDbUrl(@Named("JDBC") String dbUrl){
      this.dbUrl = dbUrl;
   }

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

輸出

編譯並執行檔案，您將看到以下輸出。

Inside checkSpelling.
jdbc:mysql://:5326/emp