java加密class和解密class加载运行

package csdn.util; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; /** 继承系统默认的类加载器，重写方法 findClass(String ) 默认抛出 异常ClassNotFoundException异常 **/ public class MyClassLoader extends ClassLoader { public static final int CLASS_LOADER_CHAR = 0X12FFAADE ; private String fname ; public MyClassLoader() { } public MyClassLoader(String fname) { this.fname = fname; } @Override protected Class<?> findClass(String name) throws ClassNotFoundException { String clazzName = name.indexOf(".") != -1 ? name.substring(name .lastIndexOf(".") + 1) : name; byte[] bs = decrypt(new File(fname + "\\" + clazzName + ".class")); return super.defineClass(name, bs, 0, bs.length); } public static void main(String[] args) throws Exception { File readFile = new File( "WebRoot\\WEB-INF\\classes\\com\\entity\\Person.class"); File writeFile = new File("booklib"); encrypt(readFile, writeFile); Class<?> clazz = new MyClassLoader("booklib") .findClass("com.entity.Person") ; System.out.println( clazz.newInstance() ) ; } static byte[] decrypt(File writeFile) { try { if (!writeFile.exists()) { return null; } InputStream is = new FileInputStream(writeFile); byte[] b = new byte[1]; ByteArrayOutputStream bos = new ByteArrayOutputStream(); int len = b.length; while (is.read(b) != -1) { for (int x = 0; x < len; x++) { b[x] = (byte) (b[x] ^ CLASS_LOADER_CHAR); } bos.write(b); } is.close(); byte[] bytes = bos.toByteArray(); bos.close(); return bytes; } catch (Exception e) { e.printStackTrace(); return null; } } static boolean encrypt(File readFile, File writeFile) { if (!readFile.exists()) { return false; } try { InputStream is = new FileInputStream(readFile); OutputStream os = new FileOutputStream(writeFile + "\\" + readFile.getName()); byte[] b = new byte[1]; int len = b.length; while (is.read(b) != -1) { for (int x = 0; x < len; x++) { b[x] = (byte) (b[x] ^ CLASS_LOADER_CHAR); } os.write(b); } is.close(); os.close(); } catch (Exception e) { e.printStackTrace(); return false; } return true; } }