Java 如何解码base64字符串并将其转换为PDF/JPG并将其保存在存储中
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How to decode base64 string and convert it into PDF/JPG and save it in storage
提问by Edoardo Goffredo
I would like to decode a base64 string and turn it into a file (as PDF/JPG) and save it to device, how for example in (/storage/emulated/0/Download/file.pdf).
我想解码 base64 字符串并将其转换为文件（如 PDF/JPG）并将其保存到设备，例如如何在（/storage/emulated/0/Download/file.pdf）中。
For encode a file I use this code:
为了对文件进行编码，我使用以下代码：
File originalFile = new File("/mnt/sdcard/download/file.pdf");
String encodedBase64 = null;
try {
FileInputStream fileInputStreamReader = new FileInputStream(originalFile);
byte[] bytes = new byte[(int) originalFile.length()];
fileInputStreamReader.read(bytes);
encodedBase64=Base64.encodeToString(bytes,Base64.NO_WRAP);
messaggio=encodedBase64.toString();
//encodedBase64 = new String(Base64.encode(bytes));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Now, I would like to decode this base64 string and convert it into a file and save it on the device.
现在，我想解码这个 base64 字符串并将其转换为文件并将其保存在设备上。
采纳答案by Prerak Sola
You can try this:
你可以试试这个：
FileOutputStream fos = new FileOutputStream(filepath);
fos.write(Base64.decode(base64String, Base64.NO_WRAP));
fos.close();
Where:
在哪里：
filepath:Path to the new filebase64String:Your base64 string that you want to convert
filepath:新文件的路径base64String:您要转换的 base64 字符串
回答by jagadishlakkurcom jagadishlakk
Give READ_STORAGE and Write_STORAGE Permission in Manifest and dont forget for RunTime Permission.
在清单中授予 READ_STORAGE 和 Write_STORAGE 权限，不要忘记运行时权限。
public static void storetoPdfandOpen(Context context, String base) {
String root = Environment.getExternalStorageDirectory().toString();
Log.d("ResponseEnv",root);
File myDir = new File(root + "/WorkBox");
if (!myDir.exists()) {
myDir.mkdirs();
}
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Attachments-" + n + ".pdf";
File file = new File(myDir, fname);
if (file.exists())
file.delete();
try {
FileOutputStream out = new FileOutputStream(file);
byte[] pdfAsBytes = Base64.decode(base, 0);
out.write(pdfAsBytes);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
File dir = new File(Environment.getExternalStorageDirectory(), "WorkBox");
File imgFile = new File(dir, fname);
Intent sendIntent = new Intent(Intent.ACTION_VIEW);
Uri uri;
if (Build.VERSION.SDK_INT < 24) {
uri = Uri.fromFile(file);
} else {
uri = Uri.parse("file://" + imgFile); // My work-around for new SDKs, causes ActivityNotFoundException in API 10.
}
sendIntent.setDataAndType(uri, "application/pdf");
sendIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
sendIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
context.startActivity(sendIntent);
}
