Java Base64 Encode Decode

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Java Base64 Encode and Decode

Java provides a class Base64 to deal with encryption. You can encrypt and decrypt your data by using provided methods. You need to import java.util.Base64 in your source file to use its methods.

This class provides three different encoders and decoders to encrypt information at each level. You can use these methods at the following levels.


Basic Encoding and Decoding

It uses the Base64 alphabet specified by Java in RFC 4648 and RFC 2045 for encoding and decoding operations. The encoder does not add any line separator character. The decoder rejects data that contains characters outside the base64 alphabet.


URL and Filename Encoding and Decoding

It uses the Base64 alphabet specified by Java in RFC 4648 for encoding and decoding operations. The encoder does not add any line separator character. The decoder rejects data that contains characters outside the base64 alphabet.


MIME

It uses the Base64 alphabet as specified in RFC 2045 for encoding and decoding operations. The encoded output must be represented in lines of no more than 76 characters each and uses a carriage return ' ' followed immediately by a linefeed ' ' as the line separator. No line separator is added to the end of the encoded output. All line separators or other characters not found in the base64 alphabet table are ignored in decoding operation.


Nested Classes of Base64

Class

Description

Base64.Decoder

This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.

Base64.Encoder

This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.


Base64 Methods

Methods

Description

public static Base64.Decoder getDecoder()

It returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.

public static Base64.Encoder getEncoder()

It returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme.

public static Base64.Decoder getUrlDecoder()

It returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.

public static Base64.Decoder getMimeDecoder()

It returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme.

public static Base64.Encoder getMimeEncoder()

It Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme.

public static Base64.Encoder getMimeEncoder(int lineLength, byte[] lineSeparator)

It returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme with specified line length and line separators.

public static Base64.Encoder getUrlEncoder()

It returns a Base64.Encoder that encodes using the URL and Filename safe type base64 encoding scheme.


Base64.Decoder Methods

Methods

Description

public byte[] decode(byte[] src)

It decodes all bytes from the input byte array using the Base64 encoding scheme, writing the results into a newly-allocated output byte array. The returned byte array is of the length of the resulting bytes.

public byte[] decode(String src)

It decodes a Base64 encoded String into a newly-allocated byte array using the Base64 encoding scheme.

public int decode(byte[] src, byte[] dst)

It decodes all bytes from the input byte array using the Base64 encoding scheme, writing the results into the given output byte array, starting at offset 0.

public ByteBuffer decode(ByteBuffer buffer)

It decodes all bytes from the input byte buffer using the Base64 encoding scheme, writing the results into a newly-allocated ByteBuffer.

public InputStream wrap(InputStream is)

It returns an input stream for decoding Base64 encoded byte stream.

 

Java Base64 Example: Basic Encoding and Decoding

  1. import java.util.Base64;  
  2. publicclass Base64BasicEncryptionExample {  
  3.     publicstaticvoid main(String[] args) {  
  4.         // Getting encoder  
  5.         Base64.Encoder encoder = Base64.getEncoder();  
  6.         // Creating byte array  
  7.         bytebyteArr[] = {1,2};  
  8.         // encoding byte array  
  9.         bytebyteArr2[] = encoder.encode(byteArr);  
  10.         System.out.println("Encoded byte array: "+byteArr2);  
  11.         bytebyteArr3[] = newbyte[5];                // Make sure it has enough size to store copied bytes  
  12.         intx = encoder.encode(byteArr,byteArr3);    // Returns number of bytes written  
  13.         System.out.println("Encoded byte array written to another array: "+byteArr3);  
  14.         System.out.println("Number of bytes written: "+x);  
  15.       
  16.         // Encoding string  
  17.         String str = encoder.encodeToString("JavaTpoint".getBytes());  
  18.         System.out.println("Encoded string: "+str);  
  19.         // Getting decoder  
  20.         Base64.Decoder decoder = Base64.getDecoder();  
  21.         // Decoding string  
  22.         String dStr = new String(decoder.decode(str));  
  23.         System.out.println("Decoded string: "+dStr);  
  24.     }  
  25. }  

Output:

Encoded byte array: [B@6bc7c054
Encoded byte array written to another array: [B@232204a1
Number of bytes written: 4
Encoded string: SmF2YVRwb2ludA==
Decoded string: JavaTpoint

Java Base64 Example: URL Encoding and Decoding

  1. import java.util.Base64;  
  2. publicclass Base64BasicEncryptionExample {  
  3.     publicstaticvoid main(String[] args) {  
  4.         // Getting encoder  
  5.         Base64.Encoder encoder = Base64.getUrlEncoder();  
  6.         // Encoding URL  
  7.         String eStr = encoder.encodeToString("http://www.javatpoint.com/java-tutorial/".getBytes());  
  8.         System.out.println("Encoded URL: "+eStr);  
  9.         // Getting decoder  
  10.         Base64.Decoder decoder = Base64.getUrlDecoder();  
  11.         // Decoding URl  
  12.         String dStr = new String(decoder.decode(eStr));  
  13.         System.out.println("Decoded URL: "+dStr);  
  14.     }  
  15. }  

Output:

Encoded URL: aHR0cDovL3d3dy5qYXZhdHBvaW50LmNvbS9qYXZhLXR1dG9yaWFsLw==
Decoded URL: http://www.javatpoint.com/java-tutorial/

Java Base64 Example: MIME Encoding and Decoding

  1. package Base64Encryption;  
  2. import java.util.Base64;  
  3. publicclass Base64BasicEncryptionExample {  
  4.     publicstaticvoid main(String[] args) {  
  5.         // Getting MIME encoder  
  6.         Base64.Encoder encoder = Base64.getMimeEncoder();  
  7.         String message = "Hello,  You are informed regarding your inconsistency of work";  
  8.         String eStr = encoder.encodeToString(message.getBytes());  
  9.         System.out.println("Encoded MIME message: "+eStr);  
  10.           
  11.         // Getting MIME decoder  
  12.         Base64.Decoder decoder = Base64.getMimeDecoder();  
  13.         // Decoding MIME encoded message  
  14.         String dStr = new String(decoder.decode(eStr));  
  15.         System.out.println("Decoded message: "+dStr);   
  16.     }  
  17. }  

Output:

Encoded MIME message: SGVsbG8sIApZb3UgYXJlIGluZm9ybWVkIHJlZ2FyZGluZyB5b3VyIGluY29uc2lzdGVuY3kgb2Yg
d29yaw==
Decoded message: Hello, 
You are informed regarding your inconsistency of work