将assets文件拷贝到SD卡中，或者拷贝到内存的data/.../files/下

public class RootPathFunction extends CordovaPlugin {
private static final String TAG = RootPathFunction.class.getSimpleName();
private String mActionName = "rootFilePath";
private Context context;
private String filePath = "/www/";
private String path;

@Override
public void initialize(CordovaInterface cordova, CordovaWebView webView) {
super.initialize(cordova, webView);
context = cordova.getActivity();
Log.e(TAG, "initialize");
File root = Environment.getExternalStorageDirectory();// getDataDirectory();
File rootRes = new File(root.getPath() + filePath);
path = rootRes.getPath();
//copyAssets("www", path);
copyAssets2("www");
}

@Override
public boolean execute(String action, JSONArray args,
CallbackContext callbackContext) throws JSONException {
Log.e(TAG, "execute action=" + action + ",args=" + args.toString());
if (action.equals(mActionName)) {
callbackContext.success(path);
return true;
} else {
callbackContext.error("rootFilePath is failed!");
return false;
}
}

private void copyAssets(String assetDir, String dir) {
String[] files;
try {
files = context.getResources().getAssets().list(assetDir);
} catch (IOException e1) {
return;
}
File mWorkingPath = new File(dir);
if (!mWorkingPath.exists()) {
mWorkingPath.mkdirs();
}
for (int i = 0; i < files.length; i++) {
try {
String fileName = files[i];
if (isFolder(fileName)) {
if (0 == assetDir.length()) {
copyAssets(fileName, dir + File.separator + fileName
+ File.separator);
} else {
copyAssets(assetDir + File.separator + fileName, dir
+ File.separator + fileName + File.separator);
}
continue;
}
File outFile = new File(mWorkingPath, fileName);
if (outFile.exists())
outFile.delete();
InputStream in = null;
if (0 != assetDir.length())
in = context.getAssets().open(
assetDir + File.separator + fileName);
else
in = context.getAssets().open(fileName);
OutputStream out = new FileOutputStream(outFile);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

String[] suffixs = { ".png", ".jpg", ".css", ".js", ".html", ".htm",
".jsp", ".apx", ".txt", ".LICENSE" };

private boolean isFolder(String fileName) {
for (int i = 0; i < suffixs.length; i++) {
if (fileName.contains(suffixs[i])) {
return false;
}
}
return true;
}

private void copyAssets2(String assetDir) {
String[] files;
try {
files = context.getResources().getAssets().list(assetDir);
} catch (IOException e1) {
return;
}
for (int i = 0; i < files.length; i++) {
try {
String fileName = files[i];
if (isFolder(fileName)) {
continue;
}
FileOutputStream fileOutputStream = context.openFileOutput(fileName, context.MODE_WORLD_WRITEABLE);
InputStream in = null;
if (0 != assetDir.length())
in = context.getAssets().open(
assetDir + File.separator + fileName);
else
in = context.getAssets().open(fileName);
OutputStream out = fileOutputStream;
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}