需求很简单 ，就是加载指定文件夹下的.so。

原因：android在程序运行的状态下 ，无法在 data/data/packageName/lib 下写文件，但可读。

还有一个引申的问题：data/app-lib/packageName/ 下的.so 和 data/data/packageName/lib 的.so 是什么关系？

1 . 获取全局的classloader

PathClassLoader pathClassLoader = (PathClassLoader)context.getClassLoader();

DexClassLoader myDexClassLoader = new DexClassLoader(str, context.getDir("dex", 0).getAbsolutePath(), str, context.getClassLoader().getParent());

2 . 获取pathList

Object pathList = getPathList(pathClassLoader);

3 . 添加路径

File[] file = new File[]{

new File("/data/app-lib/pakageName-1"),

new File("/data/app-lib/pakageName-2"),

new File("/data/data/pakageName/files"),

new File("/vendor/lib"),

new File("/system/lib")

} ;

4 . 获取当前类的属性

Object nativeLibraryDirectories=pathList.getClass().getDeclaredField("nativeLibraryDirectories");

((Field)nativeLibraryDirectories).setAccessible(true);

5 . 设置新的路径

((Field)nativeLibraryDirectories).set(pathList, file);

6 . 对classloader的操作，对应于BaseDexClassLoader:

public BaseDexClassLoader(String dexPath,File optimizedDirectory,String libraryPath,ClassLoader parent){

super(parent);

this.pathList=new DexPathList(this,dexPath,libraryPath,optimizedDirectory);

}

7 . dex,library路径对应于DexPathList, 这部分和热补丁密切相关，有兴趣可以搜下hotfix ，很多开源项目。

privatefinalElement[]dexElements; //这部分就是dex分包的了，热补丁，热补丁，热补丁

privatefinalFile[]nativeLibraryDirectories;//这部分就是 libs 加载路径了，默认有 /vendor/lib system/lib data/app-lib/packageName

最后给下代码：

public static void initNativeDirectory(Application application) {

if (hasDexClassLoader()) {

try {

createNewNativeDir(application);

} catch (Exception e) {

e.printStackTrace();

}

}

}

private static void createNewNativeDir(Context context) throws Exception{

PathClassLoader pathClassLoader = (PathClassLoader) context.getClassLoader();

Object pathList = getPathList(pathClassLoader);

//获取当前类的属性

Object nativeLibraryDirectories = pathList.getClass().getDeclaredField("nativeLibraryDirectories");

((Field) nativeLibraryDirectories).setAccessible(true);

//获取 DEXPATHList中的属性值

File[] files1 = (File[])((Field) nativeLibraryDirectories).get(pathList);

Object filesss = Array.newInstance(File.class, files1.length + 1);

//添加自定义.so路径

Array.set(filesss, 0, new File(context.getFilesDir().getAbsolutePath()));

//将系统自己的追加上

for(int i = 1;i

Array.set(filesss,i,files1[i-1]);

}

// File[] filesss = new File[file.length+ files1.length];

// filesss[0] = file[0];

// for(int i = 1;i < files1.length+1;i++){

// filesss[i] = files1[i];

// }

((Field) nativeLibraryDirectories).set(pathList, filesss);

}

private static Object getPathList(Object obj) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {

return getField(obj, Class.forName("dalvik.system.BaseDexClassLoader"), "pathList");

}

private static Object getField(Object obj, Class cls, String str) throws NoSuchFieldException, IllegalAccessException {

Field declaredField = cls.getDeclaredField(str);

declaredField.setAccessible(true);

return declaredField.get(obj);

}

/**

* 仅对4.0以上做支持

* @return

*/

private static boolean hasDexClassLoader() {

try {

Class.forName("dalvik.system.BaseDexClassLoader");

return true;

} catch (ClassNotFoundException var1) {

return false;

}

}

参考链接