我正在 Android (5.0+) 中开发一个框架/应用程序，它需要能够在没有用户交互的情况下静默安装其他“插件”/应用程序。
我开始研究 DALVIK/ART DexClassLoader 来实现这个功能。起初它似乎运行良好，我设法加载了第一个插件 .apk（我在 Android Studio 中使用普通的 gradle 构建），它解析了插件类，然后我开始创建一个实例。但是，当代码到达第二个插件时，它无法加载插件类。我认为这与类加载器有关。我得到异常 ClassNotFoundException。有谁熟悉这个问题？
private static Object ParseZipFile(Context context, File file) {
String path = file.getParentFile().getAbsolutePath() + "/" + getFilenameWithoutExtension(file) +"Install";
unzipPlugin(file, path); // /Download/Framework/plugins/someplugin.zip -> /Download/Framework/plugins/someplugin
String configPath = path+"/plugin.config";
String className = getClassNameFromConfig(configPath);
if (className == null) {
System.out.println("No plugin.config found in .zip");
return null;
}
File apkPath = new File(path);
File [] files = apkPath.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return name.endsWith(".apk");
}
});
for(File apkFile: files) {
File dexOutputDir = context.getDir("dex", Context.MODE_PRIVATE);
DexClassLoader dexClassLoader = new DexClassLoader(apkFile.getAbsolutePath(), dexOutputDir.getAbsolutePath(), null, context.getClassLoader());
try {
return GetPluginClass(dexClassLoader, className);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
}
}
return null;
}
private static Object GetPluginClass(DexClassLoader classloader, String className) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException, InstantiationException {
Log.v("loadDexClasses", "Searching for class : " + className);
Class<?> classToLoad = classloader.loadClass(className);
Object plugin = classToLoad.newInstance();
return plugin;
}
Context 是运行插件管理代码的 Android Service 的上下文。
这是堆栈跟踪
02-04 10:12:21.118 8304-8304/se.company.framework W/System.err: java.lang.ClassNotFoundException: Didn't find class "se.company.isa.IsaPlugin" on path: DexPathList[[zip file "/storage/emulated/0/Download/Framework/plugins/isaInstall/isa.apk"],nativeLibraryDirectories=[/vendor/lib64, /system/lib64]]
02-04 10:12:21.118 8304-8304/se.company.framework W/System.err: at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at se.company.pluginlib.PluginManager.GetPluginClass(PluginManager.java:204)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at se.company.pluginlib.PluginManager.ParseZipFile(PluginManager.java:151)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at se.company.pluginlib.PluginManager.loadDexClasses(PluginManager.java:122)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at fi.iki.elonen.SimpleWebServer.initPlugin(SimpleWebServer.java:125)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at fi.iki.elonen.SimpleWebServer.<init>(SimpleWebServer.java:111)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at se.company.framework.HttpdService.onStartCommand(HttpdService.java:33)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3010)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.app.ActivityThread.-wrap17(ActivityThread.java)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1442)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.os.Looper.loop(Looper.java:148)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5417)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at java.lang.reflect.Method.invoke(Native Method)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
02-04 10:12:21.119 8304-8304/se.company.framework W/System.err: Suppressed: java.lang.ClassNotFoundException: Didn't find class "se.company.isa.IsaPlugin" on path: DexPathList[[zip file "/data/app/se.company.framework-1/base.apk"],nativeLibraryDirectories=[/data/app/se.company.framework-1/lib/arm64, /vendor/lib64, /system/lib64]]
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: ... 16 more
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: Suppressed: java.lang.ClassNotFoundException: se.company.isa.IsaPlugin
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.Class.classForName(Native Method)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: ... 17 more
02-04 10:12:21.120 8304-8304/se.company.framework W/System.err: Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available