Is it possible to create a File object from InputStream

Is there any way to create a java.io.File object from an java.io.InputStream ?

My requirement is reading the File from a RAR . I am not trying to write a temporary File, I have a file inside RAR archive which I am trying to read.

7 Answers

You need to create new file and copy contents from InputStream to that file:

File file = //... try(OutputStream outputStream = new FileOutputStream(file)){ IOUtils.copy(inputStream, outputStream); } catch (FileNotFoundException e) { // handle exception here } catch (IOException e) { // handle exception here } 

I am using convenient IOUtils.copy() to avoid manual copying of streams. Also it has built-in buffering.

In one line :

FileUtils.copyInputStreamToFile(inputStream, file); 

(org.apache.commons.io)

Since Java 7, you can do it in one line even without using any external libraries:

Files.copy(inputStream, outputPath, StandardCopyOption.REPLACE_EXISTING); 

See the API docs.

Create a temp file first.

File tempFile = File.createTempFile(prefix, suffix); tempFile.deleteOnExit(); FileOutputStream out = new FileOutputStream(tempFile); IOUtils.copy(in, out); return tempFile; 

If you do not want to use other libraries, here is a simple function to copy data from an InputStream to an OutputStream.

public static void copyStream(InputStream in, OutputStream out) throws IOException { byte[] buffer = new byte[1024]; int read; while ((read = in.read(buffer)) != -1) { out.write(buffer, 0, read); } } 

Now, you can easily write an Inputstream into a file by using FileOutputStream-

FileOutputStream out = new FileOutputStream(outFile); copyStream (inputStream, out); out.close(); 

Easy Java 9 solution with try with resources block

public static void copyInputStreamToFile(InputStream input, File file) { try (OutputStream output = new FileOutputStream(file)) { input.transferTo(output); } catch (IOException ioException) { ioException.printStackTrace(); } } 

java.io.InputStream#transferTo is available since Java 9.

If you are using Java version 7 or higher, you can use try-with-resources to properly close the FileOutputStream. The following code use IOUtils.copy() from commons-io.

public void copyToFile(InputStream inputStream, File file) throws IOException { try(OutputStream outputStream = new FileOutputStream(file)) { IOUtils.copy(inputStream, outputStream); } }