如何将字节数组转换为Jar

如何将字节数组转换为Jar

这有点骇人听闻，但是他做了他的工作，这段代码基本上创建了一个伪造的url方案（myjarprotocol），当打开该方案时，它会返回该

jarBytes

字段（您的实际jar数据所在的位置）。然后通过反射它调用

SystemClassLoader.addURL

以URL作为他必须加载的jar参数。总之，SystemClassLoader被欺骗从伪造的url方案加载jar，该url方案返回您想要的任何InputStream。

public class JarLoader {    private static final byte[] jarBytes = new byte[] { 0x00  };    public static void main(String[] args) throws Exception {        URL.setURLStreamHandlerFactory(new URLStreamHandlerFactory() { public URLStreamHandler createURLStreamHandler(String urlProtocol) {     System.out.println("Someone asked for protocol: " + urlProtocol);     if ("myjarprotocol".equalsIgnoreCase(urlProtocol)) {         return new URLStreamHandler() {  @Override  protected URLConnection openConnection(URL url) throws IOException {      return new URLConnection(url) {          public void connect() throws IOException {}          public InputStream getInputStream() throws IOException {   System.out.println("Someone is getting my jar!!");   return new ByteArrayInputStream(jarBytes);          }      };  }         };     }     return null; }        });        System.out.println("Loading jar with fake protocol!");        loadJarFromURL(new URL("myjarprotocol:fakeparameter"));    }    public static final void loadJarFromURL(URL jarURL) throws Exception {        URLClassLoader systemClassloader = (URLClassLoader) ClassLoader.getSystemClassLoader();        Method systemClassloaderMethod = URLClassLoader.class.getDeclaredMethod("addURL", URL.class);        systemClassloaderMethod.setAccessible(true);        systemClassloaderMethod.invoke(systemClassloader, jarURL);        // This make classloader open the connection        systemClassloader.findResource("/resource-404");    }}