android-DexClassLoader,重新加载代码失败与信号7

我正在尝试构建一个插件系统,其中DexClassLoader正在从其他安装的包含片段(我的插件)的apk中获取代码,并在主机中显示它们.这工作得很好.

我还希望使插件可热插拔,这意味着我可以从插件更改代码,重新安装它,主机会注意到并加载新代码.如果我是第一次更改代码,这也可以. (尽管我认为不应这样做,但似乎我对这段代码有错误的理解：

try {
 requiredClass = Class.forName(fullName);
 } catch(ClassNotFoundException e) {
 isLoaded = false;
 }

)

如果我第二次尝试使用相同的插件,则主机将在requiredClass = classLoader.loadClass(fullName);下关闭.用类似的东西

libc Fatal signal 7 (SIGBUS) at 0x596ed4d6 (code=2), thread 28814
(ctivityapp.host)

是否有人对DexClassLoader的功能有更深入的了解,并且可以告诉我,这里发生了什么？我对此很困惑.

这是加载外部代码的方法的完整代码：

     /**
     * takes the name of a package as String, and tries to load the code from the corresponding akp using DexclassLaoder. 
     * Checking if a package is a valid plugin must be done before calling this. 
     * The Plugin must contain a public class UI that extends Fragment and implements plugin as a starting point for loading
     * @param packageName The full name of the package, as String
     * @return the plugins object if loaded, null otherwise
     */
    private Plugin attachPluginToHost(String packageName) {
        try {
            Class<?> requiredClass = null;
            final ApplicationInfo info = context.getPackageManager().getApplicationInfo(packageName,0);
            final String apkPath = info.sourceDir;
            final File dexTemp = context.getDir("temp_folder", 0);
            final String fullName = packageName + ".UI";
            boolean isLoaded = true;
            // Check if class loaded
            try {
                requiredClass = Class.forName(fullName);
            } catch(ClassNotFoundException e) {
                isLoaded = false;
            }
            if (!isLoaded) {
                final DexClassLoader classLoader = new DexClassLoader(apkPath, dexTemp.getAbsolutePath(), null, context.getApplicationContext().getClassLoader());
                requiredClass = classLoader.loadClass(fullName);
            }
            if (null != requiredClass) {
               // Try to cast to required interface to ensure that it's can be cast
                final Plugin plugin = Plugin.class.cast(requiredClass.newInstance());
                installedPlugins.put(plugin.getName(), plugin);
                return plugin;
            }
            } catch (PackageManager.NameNotFoundException e) {
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (InstantiationException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            return null;
    }

提前谢谢了！

解决方法:

并不是说它真的很重要(因为没有人真正在查看它),或者我什至不了解发生了什么,但是在重新加载插件之前删除dexTemp.getAbsolutePath()中的插件对应文件即可解决问题.

PS：风滚草徽章,是的！

标签：plugins,android,classloader,dexclassloader
来源： https://codeday.me/bug/20191121/2048224.html