java.io.FileNotFoundException:(Access is denied) convert byte array to image file

Question

I have a byte array, i want to create an image file(bmp file) of byte array. I create an images folder in src (my path is src/images/test.bmp). my code is in below, in

OutputStream stream = new FileOutputStream(file);

i get error. what is my problem? How can i solve this?

public static void saveImage() {
    String s="........................";
    byte[] dataCustImg = Base64.decode(s.getBytes());

    File file = new File("/images/test.bmp");
    if (file.exists()) {
        file.delete();
    }
    file = new File("/images/test.bmp");
    file.mkdirs();
    try {
        OutputStream stream = new FileOutputStream(file);

        stream.write(dataCustImg);
        stream.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

Error:

java.io.FileNotFoundException: \images\test.bmp (Access is denied)
at java.io.FileOutputStream.open(Native Method)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)

I can solve my problem with this http://stackoverflow.com/questions/6142901/how-to-create-a-file-in-a-directory-in-java link. but now i want to know how can solve my code with @EJP answer. I mean how create file and assign to fileoutputStream parameter ? — Fahim, May 23 '16 at 06:22

score 2 · Accepted Answer · answered May 23 '16 at 05:10

2

File file = new File("/images/test.bmp");

OK.

if (file.exists()) {
    file.delete();
}

Redundant. Remove. new FileOutputStream() will create a new file.

file = new File("/images/test.bmp");

Redundant. Remove. It already is a File with this name.

file.mkdirs();

The problem is here. Change to

file.getParentFile().mkdirs();

You are creating a directory called "/images/test.bmp", rather than just ensuring that "/images" exists. This will cause new FileOutputStream() to fail with an access permission, as you can't overwrite a directory with a file.

try {
    OutputStream stream = new FileOutputStream(file);

Now carry on. Note that you will first have to delete the directory "/images/test.bmp", manually.

answered May 23 '16 at 05:10

user207421

305,947
44
307
483

Thanks for reply, but when i have images folder in src path, now i want to save test.bmp in images folder, i should create file with File file=new File("/images/"), this is true? if yes how can save in test.bmp?how can set this in fileoutputstream? Sorry if my English is bad – Fahim May 23 '16 at 05:57
please answer to my questions. Thanks a lot – Fahim May 23 '16 at 06:20
You don't need to do anything other that what I've stated above. I didn't say anything about `new File("/images")`. I don't know where you got that from, or what part of my answer you don't understand. – user207421 May 24 '16 at 05:34

score 0 · Answer 2 · answered May 23 '16 at 05:09

0

Here when you are calling mkdir then it is creating test.bmp as a directory not as a file, SO you have to first create directory and then you can create file. see the below code.

        File dir = new File("/images/");
        dir.mkdirs();
        file = new File("/images/test.bmp");
        file.createNewFile();

answered May 23 '16 at 05:09

Naveen Ramawat

1,425
1
15
27

The `createNewFile()` call is redundant. `new FileOutputStream()` will do that. – user207421 May 23 '16 at 05:16

SubOptimal · Answer 3 · 2016-05-23T06:22:21.447

The reason for the exception is that you actually create a directory with the path /images/test.bmp

file = new File("/images/test.bmp");
file.mkdirs();

and later you want to open a file

OutputStream stream = new FileOutputStream(file);

If you want to ensure that the directory /images exist before you create the file you should use

File dir = new File("/images/");
dir.mkdirs();

The explicit delete before writing to the file isn't necessary, as the file would be overwritten by default.

Find a small working snippet below.

// create the directory if not exist
File dir = new File("/images/");
dir.mkdirs();
// create a new file or overwrite an existing one
File file = new File("/images/test.bmp");
try (OutputStream os = new FileOutputStream(file)) {
    os.write((int) System.currentTimeMillis());
}

kgym · Answer 4 · 2016-05-24T05:22:36.843

-1

public static void saveImage() {
    String s="........................";
    byte[] dataCustImg = Base64.decode(s.getBytes());

    File file = new File("/images/test.bmp");
    if(!file.getParentFile().exists()) {
      file.getParentFile().mkdirs();
    }
    if(!file.exists()) {
      try {
        file.createNewFile();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
    // because stream.write(dataCustImg) will overwrite the file if the file has already existed.
    try {
        OutputStream stream = new FileOutputStream(file);

        stream.write(dataCustImg);
        stream.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

edited May 24 '16 at 05:22

answered May 23 '16 at 05:18

kgym

29
3

@Fahim， I have edit the code above and tested it. It works in my computer. Suggest to use File.separator instead of "/" and "\". – kgym May 24 '16 at 05:24
The `exists()/createNewFile()` block is a complete and utter waste of time. The operating system has to do exactly that when `new FileOutputStream()` is called. You're forcing it to do it all twice. The existence check on the parent directory is pointless and wasteful as well, as `mkdirs()` already does it inside the OS. – user207421 May 24 '16 at 05:35
@EJP Now, I see. Thank you! – kgym May 24 '16 at 05:40

java.io.FileNotFoundException:(Access is denied) convert byte array to image file

4 Answers4