Android动态加载jar/dex遇到的问题

Question

想法：实现与腾讯游戏大厅融合自身开发游戏的方式，安装了游戏大厅后对于腾讯自主研发的游戏比如：斗地主，用户无需安装就可以直接使用。

设计思路：把子apk放到assets目录中，在主程序中将此apk拷贝到SD卡中，用动态加载方式去调用。

实现：

public void loadAPK(Bundle paramBundle, String dexpath, String dexoutputpath) {
    ClassLoader localClassLoader = ClassLoader.getSystemClassLoader();
    DexClassLoader localDexClassLoader = new DexClassLoader(dexpath,
				dexoutputpath, null, localClassLoader);
    try {
	PackageInfo plocalObject = getPackageManager().getPackageArchiveInfo(dexpath, 1);
	if ((plocalObject.activities != null)&& (plocalObject.activities.length > 0))         {
		String activityname = plocalObject.activities[0].name;
		Log.d(TAG, "activityname = " + activityname);
		Class localClass = localDexClassLoader.loadClass(activityname);
		Constructor localConstructor = localClass.getConstructor(new Class[] {});
		Object instance = localConstructor.newInstance(new Object[] {});
		Log.d(TAG, "instance = " + instance);
		Method localMethodSetActivity = localClass.getDeclaredMethod("setActivity", new Class[] { Activity.class });
		localMethodSetActivity.setAccessible(true);
		localMethodSetActivity.invoke(instance, new Object[] { this });
		Method methodonCreate = localClass.getDeclaredMethod("onCreate", new Class[] { Bundle.class });
//		Method methodonCreate = localClass.getDeclaredMethod("init", new Class[]{String.class});
		methodonCreate.setAccessible(true);
		methodonCreate.invoke(instance, paramBundle);
		}
			return;
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}

采用以上方法在外置SD卡（/mnt/sdcard/）上可以启动子apk，但在内置SD卡（/storage/sdcard0）中无法启动，报错语句：

DexClassLoader localDexClassLoader = new DexClassLoader(dexpath,
				dexoutputpath, null, localClassLoader);

错误信息如下：

java.lang.IllegalArgumentException: Optimized data directory /storage/sdcard0 is not owned by the current user. Shared storage cannot protect your application from code injection attacks.

Answer 1

指定dexoutputpath为APP自己的缓存目录即可。

File dexOutputDir = context.getDir("dex", 0);

DexClassLoader localDexClassLoader = new DexClassLoader(dexpath, dexOutputDir.getAbsolutePath(), null, ClassLoader.getSystemClassLoader().getParent());

详见http://blog.csdn.net/yangjunjiezai/article/details/8668265

Answer 2

.dex文件在4.1之后是不能保存在sd卡下的