15.5 ClassLoader(血干JAVA系类)

• • • • 【例15.20】取得类加载器
      • 【例15.21】定义要加载的自定义类——Salgrade
      • 【例15.22】使用自定义类加载器
      • 代码：文件输入

public class demo 
{
	public static void main(String[] args) throws Exception
	{		
		Class cls = demo.class;//实例化Class
		System.out.println(cls.getClassLoader());
		System.out.println(cls.getClassLoader().getParent());
	}
}

class My extends ClassLoader
{
	public Class getmyclass(String classpath) throws Exception
	{
		return super.loadClass(classpath);
	}
}

class Sa
{
	public Sa()
	{
		System.out.println("---------Sa-------");
	}
}

package file;
class Sa
{
	public Sa()
	{
		System.out.println("---------Sa-------");
	}
}
class My extends ClassLoader
{
	public Class getmyclass(String classpath) throws Exception
	{
		return super.loadClass(classpath);
	}
}
public class demo 
{
	public static void main(String[] args) throws Exception
	{		
		My my = new My();//实例化类加载器对象
		Class cls = my.getmyclass("file.Sa");//利用类加载器取得对象
		System.out.println(cls.newInstance());//实例化类对象
	}
}