public class MyClassLoader extends ClassLoader {

    private String path;

    private String classLoaderName;

    public MyClassLoader(String path, String classLoaderName) {

        this.path = path;

        this.classLoaderName = classLoaderName;

    }

    //用于寻找类文件

    @Override

    public Class findClass(String name) {

        byte[] b = loadClassData(name);

        return defineClass(name, b, 0, b.length);

    }

    //用于加载类文件

    private byte[] loadClassData(String name) {

        name = path + name + ".class";

        InputStream in = null;

        ByteArrayOutputStream out = null;

        try {

            in = new FileInputStream(new File(name));

            out = new ByteArrayOutputStream();

            int i = 0;

            while ((i = in.read()) != -1) {

                out.write(i);

            }

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                out.close();

                in.close();

            } catch (Exception e) {

                e.printStackTrace();

            }

        }

        return out.toByteArray();

    }

}

public class ClassLoaderChecker {

    public static void main(String[] args) throws ClassNotFoundException, IllegalAccessException, InstantiationException {

        MyClassLoader m = new MyClassLoader("/Users/baidu/Desktop/", "myClassLoader");

        Class c = m.loadClass("Wali");

        c.newInstance();

    }

}

public class LoadDifference {

    public static void main(String[] args) throws Exception {

        //loadClass加载类，需要调用c.newInstance()才会加载类

        ClassLoader cl = Robot.class.getClassLoader();

        Class c = cl.loadClass("com.interview.javabasic.reflect.Robot");

        c.newInstance();

        //forName加载类，在加载类的时候会将Static静态代码块的代码实现出来

        Class r = Class.forName("com.interview.javabasic.reflect.Robot");

    }

}