Decode base64 image in Grails

Question

I have a post api where I am sending a json string which contain the base64 encoded image.Below is the json string

{ "imageData":"base64encoded string",
  "status":"1"
}

where base64encode string is iVBORw0KGgoAAAANSUhEUgAAAHgAAACgCAIAAABIaz/HAAAAAXNSR0IArs4c6QAA\r\nABxpRE9UAAAAAgAAAAAAAABQAAAAKAAAAFAAAABQAABWL3xrAqoAAEAASURBVHgB\r\nlL2Fe1t7mueZme6uewNGMUu2LNkyySSjDJKZmZkSO8zM7CTmmJnZYbxUVbdgsKp7\r\nqqdrdp

I cant post the complete encoding since its too lengthy. How can I convert this encoded string into a image file at server side.Actually from there I suppose to upload the image on a ftp server.

aveuiller · Accepted Answer · 2015-06-18T07:42:30.270

1

Base64 uses Ascii characters to send binary files, so to retrieve your image, you basically have to decode the Base64 string back to a byte array and save it to a file.

String encoded = 'iVBORw0KGgoAAAANSUhEUg' // You complete String
encoded.replaceAll("\r", "")
encoded.replaceAll("\n", "")
byte[] decoded = encoded.decodeBase64()
new File("file/path").withOutputStream {
  it.write(decoded);
}

Edit: You problem of invalid charatercomes from the \r\n characters you have in the encoded String, you must have your base64 string in one line to decode it. I updated the sample code to do it.

edited Jun 18 '15 at 07:42

answered Jun 18 '15 at 07:07

aveuiller

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Thanks for reply , I have tried this then it is throwing the error Message: bad character in base64 value – Saurabh Mishra Jun 18 '15 at 07:25
still getting the same error. – Saurabh Mishra Jun 18 '15 at 07:52
2

I know this is old, but the problem is that replaceAll does not mutate the string in place. You need to do something like encoded = encoded.replaceAll('[\r\n]', '') – David Jun 20 '16 at 01:58

Decode base64 image in Grails

1 Answers1