让我们创建一个基于控制台的示例应用程序,我们将逐步使用Guice绑定机制演示依赖注入.
步骤1:创建接口
//spell checker interfaceinterface SpellChecker { public void checkSpelling();}
第2步:创建实施
//spell checker implementationclass SpellCheckerImpl implements SpellChecker { @Override public void checkSpelling() { System.out.println("Inside checkSpelling." ); } }
步骤3:创建绑定模块
//Binding Moduleclass TextEditorModule extends AbstractModule { @Override protected void configure() { bind(SpellChecker.class).to(SpellCheckerImpl.class); }}
步骤4:创建具有依赖性的类
class TextEditor { private SpellChecker spellChecker; @Inject public TextEditor(SpellChecker spellChecker) { this.spellChecker = spellChecker; } public void makeSpellCheck() { spellChecker.checkSpelling(); } }
步骤5:创建注入器
Injector injector = Guice.createInjector(new TextEditorModule());
步骤6:获取完成依赖关系的对象
TextEditor editor = injector.getInstance(TextEditor.class);
步骤7:使用对象
editor.makeSpellCheck() ;
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;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 Moduleclass TextEditorModule extends AbstractModule { @Override protected void configure() { bind(SpellChecker.class).to(SpellCheckerImpl.class); } }//spell checker interfaceinterface SpellChecker { public void checkSpelling();}//spell checker implementationclass SpellCheckerImpl implements SpellChecker { @Override public void checkSpelling() { System.out.println("Inside checkSpelling." ); } }
输出
编译并运行文件,你会看到以下输出.
Inside checkSpelling.