Guice还提供了另一种在不创建自定义注释的情况下映射绑定的方法.它允许使用@Named注释.
使用命名注释进行映射
bind(SpellChecker.class).annotatedWith(Names.named("OpenOffice")).to(OpenOfficeWordSpellCheckerImpl.class);
使用@Named注释进行注入
@Injectpublic TextEditor(@Named("OpenOffice") SpellChecker spellChecker) { this.spellChecker = spellChecker; }
完整示例
创建一个名为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;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(@Named("OpenOffice") SpellChecker spellChecker) { this.spellChecker = spellChecker; } public void makeSpellCheck() { spellChecker.checkSpelling(); } }//Binding Moduleclass TextEditorModule extends AbstractModule { @Override protected void configure() { bind(SpellChecker.class).annotatedWith(Names.named("OpenOffice")) .to(OpenOfficeWordSpellCheckerImpl.class); } }//spell checker interfaceinterface SpellChecker { public void checkSpelling();}//spell checker implementationclass SpellCheckerImpl implements SpellChecker { @Override public void checkSpelling() { System.out.println("Inside checkSpelling." ); } }//subclass of SpellCheckerImplclass OpenOfficeWordSpellCheckerImpl extends SpellCheckerImpl { @Override public void checkSpelling() { System.out.println("Inside OpenOfficeWordSpellCheckerImpl.checkSpelling." ); }}
输出
编译并运行文件,你会看到以下输出.
Inside OpenOfficeWordSpellCheckerImpl.checkSpelling..