谁加载了我　– 1.普通的Main程序

在普通的Main程序中，
某个类是被哪个加载器所加载的？

		print(String.class.getClassLoader()); //打印null, 这在HotSpot里代表Bootstrap ClassLoader，它负责加载$JAVA_HOME/lib里的类库
		print(List.class.getClassLoader()); // 同上

		
		
		
		print(learn.classloader.WhoLoadsMe.class.getClassLoader()); // 打印sun.misc.Launcher$AppClassLoader，它在HotSpot里代表System Class Loader, 负责加载用户类路径上的类库						
		print(learn.classloader.Friend.class.getClassLoader()); //同上
		
		//看看sun.misc.Launcher$AppClassLoader的父加载器和祖父加载器是哪些
		print(learn.classloader.Friend.class.getClassLoader().getParent()); //打印sun.misc.Launcher$ExtClassLoader,它在HotSpot里用于加载$JAVA_HOME/lib/ext下的类库
		print(learn.classloader.Friend.class.getClassLoader().getParent().getParent()); //打印null, 即Bootstrap ClassLoader
		
		
		
		
		Class<?> remoteFriendClass = new learn.classloader.RemoteClassLoader().loadClass(
				"learn.classloader.RemoteFriend");  
		print(remoteFriendClass.getClassLoader());  //打印 learn.classloader.RemoteClassLoader,即自写的class loader(后文有这个class loader的代码)

		//看看自写加载器的父加载器是哪个
		print(remoteFriendClass.getClassLoader().getParent()); //打印sun.misc.Launcher$AppClassLoader,即System ClassLoader

		print(remoteFriendClass.getField("friendOfFriend").getType()
				.getClassLoader()); //同上, 这意味着在"RemoteFriend"里直接引用的类(后文附上了代码描述这个引用)是由RemoteFriend的加载器所加载的


		//最后看下context class loader
		print(Thread.currentThread().getContextClassLoader()); //打印sun.misc.Launcher$AppClassLoader，即system classloader

附：
RemoteClassLoader

package learn.classloader;
public class RemoteClassLoader extends ClassLoader {
	@Override
	public Class<?> loadClass(String name) throws ClassNotFoundException {
		Class<?> clazz = findLoadedClass(name);
		if (clazz != null) {
			return clazz;
		}
		clazz = letParentLoad(name);
		if (clazz != null) {
			return clazz;
		}

		String classDir = "/home/kent/another-project/classes/";
		String classFile = classDir + name.replaceAll("\\.", "\\/") + ".class";
		byte[] bytes = readToBytes(classFile);
		return defineClass(name, bytes, 0, bytes.length);
	}
...
}

附：
RemoteFriend类里的FriendOfFriend

package learn.classloader;

public class RemoteFriend {
	
	public static FriendOfFriend friendOfFriend = new FriendOfFriend();

}