由于Spring太过庞大，所以本人也一直都不太喜欢，当guice1出来时，就关注过一阵子，但始终没有行动去试用，听说2.0出来了，最近闲着也没事，就去试用了一下，单从IOC方面来说，做得的确比较出色。
于是做了一个例子，把常用的功能都试了一下，其中需要的JAR包只有两个：
aopalliance.jar
guice-2.0.jar
下面是例子的代码：
public interface Service { public void sayHello();}public class ServiceImp implements Service { public void sayHello() { System.out.println("ServiceImp say Hello !"); }}
然后需要一个Model建立接口与类之间的映射关系,
由于包含的功能比较多，所以代码相对有一点复杂,不过这个类是最重要的
import java.io.IOException;import java.io.InputStream;import java.util.Properties;import com.google.inject.AbstractModule;import com.google.inject.Binder;import com.google.inject.Provides;import com.google.inject.name.Names;import demo.HeroModule;public class ServiceModel extends AbstractModule { @Override protected void configure() { // 与在Service接口上声明@ImplementedBy(ServiceImp.class)等价 // 手工实例化想绑定的对象 // this.bind(Service.class).toInstance(new ServiceImp()); // this.bind(Service.class).to(ServiceImp.class); // When your @Provides methods start to grow complex, you may consider // moving them to a class of their own this.bind(Service.class).toProvider(ServiceProvider.class); // this.bind(String.class).annotatedWith(Names.named("username")).toInstance("qiuqiu"); this.bindConstant().annotatedWith(Names.named("username")).to("qiuqiu"); loadProperties(); } /* * When you need code to create an object, use an @Provides method. The * method must be defined within a module, and it must have an @Provides * annotation. The method's return type is the bound type. Whenever the * injector needs an instance of that type, it will invoke the method. */ @Provides public User provide() { System.out.println("++++++++============="); User user = new User(); user.setUsername("myprovide"); return user; } private void loadProperties() { InputStream stream = this.getClass().getResourceAsStream( "/app.properties"); Properties appProperties = new Properties(); try { appProperties.load(stream); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } Names.bindProperties(this.binder(), appProperties); }}
Provider在管理手工创建对象时会比@Provides灵活一些:
import com.google.inject.Provider;public class ServiceProvider implements Provider<Service> { @Override public Service get() { System.out.println("ServiceProvider==-=-=-=-=_+_+_+_+_+_+_+_+"); // TODO Auto-generated method stub Service service = new ServiceImp(); return service; }
}
还有一辅助类：
public class User{ private String username; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; }}
还有一属性文件app.properties，很简单：
db.user=mysql
db.pwd=2009
经过上面一系列的准备，就可以进行测试了了：
import org.testng.Assert;import org.testng.annotations.Test;import com.google.inject.Guice;import com.google.inject.Inject;import com.google.inject.Injector;import com.google.inject.name.Named;public class Client { private Service service; private User user; private String username; private String db_user; private String db_pwd; @Inject public void setDB(@Named("db.user") String db_user, @Named("db.pwd") String db_pwd) { this.db_user = db_user; this.db_pwd = db_pwd; } @Inject public void setUsername(@Named("username") String username) { this.username = username; } @Inject public void setUser(User user) { this.user = user; } @Inject public void setService(Service service) { this.service = service; } @Test public void testGuice() { Injector injector = Guice.createInjector(new ServiceModel()); // 如果不用@Inject注入，则用这种方法 // Service service = injector.getInstance(ServiceImp.class); injector.injectMembers(this); service.sayHello(); } @Test public void testBindConstant() { System.out.println("username=" + username); } @Test public void testBindProvides() { Injector injector = Guice.createInjector(new ServiceModel()); injector.injectMembers(this); // 必须要调用上面的注入方法 Assert.assertEquals(user.getUsername(), "myprovide"); } @Test public void testProperties() { Injector injector = Guice.createInjector(new ServiceModel()); injector.injectMembers(this); Assert.assertEquals(db_user, "mysql"); Assert.assertEquals(db_pwd, "2009"); }}
大体过程就这样，还有一些细小的功能没有仔细去体会，以后有时间再来完善吧！
相关资源：[Google Guice] Google Guice 学习教程 (英文版)
