Thursday, January 19, 2017

Java 8 - Base64

With Java 8, Base64 has finally got its due. Java 8 now has inbuilt encoder and decoder for Base64 encoding. In Java 8, we can use three types of Base64 encoding −

  • Simple − Output is mapped to a set of characters lying in A-Za-z0-9+/. The encoder does not add any line feed in output, and the decoder rejects any character other than A-Za-z0-9+/.
  • URL − Output is mapped to set of characters lying in A-Za-z0-9+_. Output is URL and filename safe.
  • MIME − Output is mapped to MIME friendly format. Output is represented in lines of no more than 76 characters each, and uses a carriage return '\r' followed by a linefeed '\n' as the line separator. No line separator is present to the end of the encoded output.

Nested Classes

S. No. Nested class & Description
1 static class Base64.Decoder This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
2 static class Base64.Encoder This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.

Methods

S. No. Method Name & Description
1 static Base64.Decoder getDecoder() Returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.
2 static Base64.Encoder getEncoder() Returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme.
3 static Base64.Decoder getMimeDecoder() Returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme.
4 static Base64.Encoder getMimeEncoder()
Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme.
5 static Base64.Encoder getMimeEncoder(int lineLength, byte[] lineSeparator) Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme with specified line length and line separators.
6 static Base64.Decoder getUrlDecoder() Returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.
7 static Base64.Encoder getUrlEncoder() Returns a Base64.Encoder that encodes using the URL and Filename safe type base64 encoding scheme.

Methods Inherited

Base64 class inherits few methods from the java.lang.Object class.

Base64 Example

Let us see an example to see Base64 in practice −

Java8Tester.java

import java.util.Base64;
import java.util.UUID;
import java.io.UnsupportedEncodingException;

public class HelloWorld {
   public static void main(String args[]){
      try {
  
         // Encode using basic encoder
         String base64encodedString = Base64.getEncoder().encodeToString("TutorialsPoint?java8".getBytes("utf-8"));
         System.out.println("Base64 Encoded String (Basic) :" + base64encodedString);
  
         // Decode
         byte[] base64decodedBytes = Base64.getDecoder().decode(base64encodedString);
  
         System.out.println("Original String: " + new String(base64decodedBytes, "utf-8"));
         base64encodedString = Base64.getUrlEncoder().encodeToString("TutorialsPoint?java8".getBytes("utf-8"));
         System.out.println("Base64 Encoded String (URL) :" + base64encodedString);
  
         StringBuilder stringBuilder = new StringBuilder();
  
         for (int i = 0; i < 10; ++i) {
            stringBuilder.append(UUID.randomUUID().toString());
         }
  
         byte[] mimeBytes = stringBuilder.toString().getBytes("utf-8");
         String mimeEncodedString = Base64.getMimeEncoder().encodeToString(mimeBytes);
         System.out.println("Base64 Encoded String (MIME) :" + mimeEncodedString);
         
      }catch(UnsupportedEncodingException e){
         System.out.println("Error :" + e.getMessage());
      }
   }
}

Verify the Result

Compile the class using javac compiler as follows −
$javac Java8Tester.java
Now run the Java8Tester as follows −
$java Java8Tester
It should produce the following output −
Base64 Encoded String (Basic) :VHV0b3JpYWxzUG9pbnQ/amF2YTg=
Original String: TutorialsPoint?java8
Base64 Encoded String (URL) :VHV0b3JpYWxzUG9pbnQ_amF2YTg=
Base64 Encoded String (MIME) :ZWJjY2YzZWUtYmUwZC00Yjg1LTlkYjUtNWUyMzBlNWI
4ZGQ4ZjE1NGJmMjEtNTdkNi00YzM1LTg4
MzYtNDZlYzNhZDM2NTdkZmQzY2RiNzMtMTU1OC00ZjBmLWFmZGQtM2YyZWU3MDYzZjQwNzVhY
WQ0
ODctZWEyZS00YzM2LWEyZmUtOGVkMmNjMGNmZGM3MTg5YWUyZGQtMzg4MS00M2NkLWI2NDEtZ
jNh
Zjk2OGIxZDU2YzkzODZlYTUtNjljNC00ZmIyLTkzYTQtMzVlOTFlNjdlY2E0MDcwNWExMWItM
mE4
Yy00OTljLTg2NmItMjE3ZTZmMmIyY2NiNzI2MjAwZWQtMjI0NC00YzJhLWJiMGItOTczMDJkM
zIx
NGFkY2QyZmVhODItNmUyOS00MWNjLWFlODItNzdmNzRhYmQ4NGU5ZGQ3ZjY3NzktZjgwYi00M
zlk
LTlmNDgtOTNlNTIwYzIzZDcy

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