The file storage provided by mPaaS provides file encryption capability based on Android native File
.
Note: Because the file encryption uses the encryption function provided by Mobile Security Guard, you must ensure that the encryption images in Mobile Security Guard have been correctly generated.
File types
- ZFile: This type of files are stored in
data/data/package_name/files
. - ZExternalFile: This type of files are stored in
sdcard/Android/data/package_name/files
. - ZFileInputStream/ZFileOutputStream: File storage input/output stream, the files will not be encrypted if you use this stream.
- ZSecurityFileInputStream/ZSecurityFileOutputStream: Secure file storage input/output stream, the files will be encrypted if you use this stream.
Examples
Convert files to text
/**
* Convert files to text
* @param file: File
* @return Text
*/
public String file2String(File file) {
InputStreamReader reader = null;
StringWriter writer = new StringWriter();
try {
// Use decryption input stream ZSecurityFileInputStream
// If you don’t use encryption/decryption function, then use ZFileInputStream
reader = new InputStreamReader(new ZSecurityFileInputStream(file, this));
//Write the input stream into the output stream
char[] buffer = new char[DEFAULT_BUFFER_SIZE];
int n = 0;
while (-1 != (n = reader.read(buffer))) {
writer.write(buffer, 0, n);
}
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (reader != null)
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//Return the coversion result
if (writer != null) {
return writer.toString();
} else {
return null;
}
}
Convert text to files
/**
* Convert text to files
* @param res: Text
* @param file: File
* @return true means successful while false means failed
*/
public boolean string2File(String res, File file) {
boolean flag = true;
BufferedReader bufferedReader = null;
BufferedWriter bufferedWriter;
try {
bufferedReader = new BufferedReader(new StringReader(res));
// Use decryption output stream ZSecurityFileOutputStream
// If you don’t use encryption/decryption function, then use ZFileOutputStream
bufferedWriter = new BufferedWriter(new OutputStreamWriter(new ZSecurityFileOutputStream(file, this)));
//Character buffers
char buf[] = new char[DEFAULT_BUFFER_SIZE];
int len;
while ((len = bufferedReader.read(buf)) != -1) {
bufferedWriter.write(buf, 0, len);
}
bufferedWriter.flush();
bufferedReader.close();
bufferedWriter.close();
} catch (Exception e) {
e.printStackTrace();
flag = false;
return flag;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return flag;
}
Insert files
/**
* Insert files
*
* @param file: File
*/
private void insertFile(BaseFile file) {
if (null == file) {
return;
}
StringBuilder sb = new StringBuilder();
String content = sb.append(file.getName())
.append(' ')
.append(SIMPLE_DATE_FORMAT.format(new Date(System.currentTimeMillis()))).toString();
string2File(content, file);
try {
if (!file.exists()) {
file.createNewFile();
}
mData.add(file);
} catch (Exception e) {
e.printStackTrace();
}
}
Delete files
/**
* Delete files
*
* @param file: File
*/
private void deleteFile(BaseFile file) {
try {
file.delete();
mData.remove(file);
} catch (Exception e) {
e.printStackTrace();
}
}