测试用例跑通,提出pr

src/main/java/club/shengsheng/MyClassLoader.java

@@ -1,9 +1,75 @@
 package club.shengsheng;
 
 
+import java.io.File;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.file.Paths;
+
 /**
  * @author gongxuanzhangmelt@gmail.com
  **/
 public class MyClassLoader extends ClassLoader {
 
+    @Override
+    public Class<?> loadClass(String name,boolean resolve) throws ClassNotFoundException {
+        synchronized (getClassLoadingLock(name)) {
+            // First, check if the class has already been loaded
+            Class<?> c = findLoadedClass(name);
+            if (c == null) {
+                if (name.startsWith("tech")){ //加载我们自己的包名
+                    c = findClass(name);
+                }else{ //如果是其他包名,用父类加载器去加载
+                    c = getParent().loadClass(name);
+                }
+            }
+            if (resolve) {
+                resolveClass(c);
+            }
+            return c;
+        }
+    }
+
+    @Override
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        String absolutePath = Paths.get("").toAbsolutePath().toString();
+        String filePath = absolutePath + File.separator +"加密.class";
+        System.out.println("filePath = " + filePath);
+        File file = new File(filePath);
+        ByteBuffer byteBuffer = handlerClass(file);
+
+        return defineClass(name, byteBuffer.array(), 0, byteBuffer.limit());
+    }
+
+    private static ByteBuffer handlerClass(File file) {
+        ByteBuffer buffer = ByteBuffer.allocate((int) file.length());
+        System.out.println("file.length(): " + file.length());
+        try(FileChannel channel = new RandomAccessFile(file,"r").getChannel()){
+            //准备缓冲区
+            ByteBuffer tempBuff = ByteBuffer.allocate(20); //10字节
+            while(true){
+                //从 channel 中读取数据, 向 buffer 中写入
+                int len = channel.read(tempBuff);
+                if (len == -1){
+                    break; //没有数据了
+                }
+                //切换到读模式
+                tempBuff.flip();
+                //打印 buffer 中的内容
+                while(tempBuff.hasRemaining()){
+                    byte b = tempBuff.get(); //一个字节一个字节取
+                    b -= (byte)1;
+                    System.out.print(String.format("0x%02X ", b));
+                    buffer.put(b);
+                }
+                System.out.println();
+                tempBuff.clear(); //切换为写模式
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return buffer;
+    }
+
 }