Guice系列之用户指南（九）

原文地址：https://code.google.com/p/google-guice/wiki/JustInTimeBindings

JustInTimeBindings（即时绑定）：主要是在@ImplementedBy和@ProvidedBy实现。

贴代码：

import com.google.inject.ImplementedBy;

@ImplementedBy(Cat.class)
public interface Animal {
	void say();
}

public class Cat implements Animal {
	@Override
	public void say() {
		System.out.println("i am a cat");
	}
}

import com.google.inject.ProvidedBy;

@ProvidedBy(HumenProvider.class)
public interface Humen {
	void say();
}

import com.google.inject.Provider;

public class HumenProvider implements Provider<Humen> {
	@Override
	public Humen get() {
		Humen humen = new Student();
		System.out.println("Provider.get()");
		return humen;
	}
}

public class Student implements Humen {
	@Override
	public void say() {
		System.out.println("i am a student");
	}
}

import com.google.inject.Guice;
import com.google.inject.Injector;

public class Test {
	public static void main(String[] args) {
		Injector injector = Guice.createInjector();
		Animal animal = injector.getInstance(Animal.class);
		System.out.println(animal.getClass().getSimpleName());
		animal.say();
		Humen humen = injector.getInstance(Humen.class);
		System.out.println(humen.getClass().getSimpleName());
		humen.say();
	}
}

执行结果：
Cat
i am a cat
Provider.get()
Student
i am a student

练习代码在这里