Guice提供了一种使用toConstructor()方法创建与对象的特定构造函数绑定的方法.
@Override protected void configure() { try { bind(SpellChecker.class) .toConstructor(SpellCheckerImpl.class.getConstructor(String.class)); } catch (NoSuchMethodException | SecurityException e) { System.out.println("Required constructor missing"); } }
请参阅下面的完整示例.
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( SpellChecker spellChecker) { this.spellChecker = spellChecker; } public void makeSpellCheck() { spellChecker.checkSpelling(); } } //Binding Module class TextEditorModule extends AbstractModule { @Override protected void configure() { try { bind(SpellChecker.class) .toConstructor(SpellCheckerImpl.class.getConstructor(String.class)); } catch (NoSuchMethodException | SecurityException e) { System.out.println("Required constructor missing"); } bind(String.class) .annotatedWith(Names.named("JDBC")) .toInstance("jdbc:mysql://localhost:5326/emp"); } } //spell checker interface interface SpellChecker { public void checkSpelling(); } //spell checker implementation class SpellCheckerImpl implements SpellChecker { private String dbUrl; public SpellCheckerImpl(){} public SpellCheckerImpl(@Named("JDBC") String dbUrl) { this.dbUrl = dbUrl; } @Override public void checkSpelling() { System.out.println("Inside checkSpelling." ); System.out.println(dbUrl); } }
编译并运行文件,你会看到以下输出.
Inside checkSpelling. jdbc:mysql://localhost:5326/emp