Create XlassLoader.java

XlassLoader.java

@@ -0,0 +1,55 @@
+package jvm;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.lang.reflect.Method;
+
+public class XlassLoader extends ClassLoader {
+    public static void main(String[] args) throws Exception {
+        // 类名和方法名
+        String className = "Hello";
+        String methodName = "hello";
+
+        ClassLoader classLoader = new XlassLoader();
+
+        Class<?> aClass = classLoader.loadClass(className);
+
+//        for (Method m : aClass.getMethods()) {
+//            System.out.println(m.getName());
+//        }
+
+        // 创建对象
+        Object obj = aClass.getDeclaredConstructor().newInstance();
+
+        // 调用方法
+        Method method = aClass.getMethod(methodName);
+        method.invoke(obj);
+    }
+
+    @Override
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        try (FileInputStream input = new FileInputStream("E:\\IdeaProjects\\geektime-java\\out\\production\\geektime-java\\resource\\Hello.xlass")) {
+            int len = input.available();
+            byte[] bytes = new byte[len];
+            input.read(bytes);
+            // 按字节转换xlass
+            byte[] classBytes = decode(bytes);
+            return defineClass(name, classBytes, 0, classBytes.length);
+        } catch (IOException e) {
+            throw new ClassNotFoundException(name, e);
+        }
+    }
+
+    private byte[] decode(byte[] bytes) {
+        int len = bytes.length;
+        byte[] targetBytes = new byte[len];
+        for (int i = 0; i < len; i++) {
+            targetBytes[i] = (byte) (0b11111111 ^ bytes[i]);
+        }
+        return targetBytes;
+    }
+
+
+}