How to convert InputStream to byte array in Java

Question

How do I read an entire InputStream into a byte array?

Thanxx in advanced!!

Answer 1

Hello @kartik,

You need to read each byte from your InputStream and write it to a ByteArrayOutputStream. 

You can then retrieve the underlying byte array by calling toByteArray(); e.g.  

InputStream is = ...

ByteArrayOutputStream buffer = new ByteArrayOutputStream();

int nRead;
byte[] data = new byte[16384];

while ((nRead = is.read(data, 0, data.length)) != -1) {
  buffer.write(data, 0, nRead);
}

return buffer.toByteArray();

Hope this helps!!

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Thank you!!

Answer 2

The class IOUtils, lib: https://mvnrepository.com/artifact/commons-io/commons-io/2.8.0,  can help you.