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I want to encode a string into base64 and transfer it through a socket and decode it back.
But after decoding it gives different answer.
Following is my code and result is "77+9x6s="
import javax.xml.bind.DatatypeConverter;
public class f{
public static void main(String a[]){
String str = new String(DatatypeConverter.parseBase64Binary("user:123"));
String res = DatatypeConverter.printBase64Binary(str.getBytes());
System.out.println(res);
}
}
Any idea about how to implement this?
6 Answers
You can use following approach:
import org.apache.commons.codec.binary.Base64;
// Encode data on your side using BASE64
byte[] bytesEncoded = Base64.encodeBase64(str.getBytes());
System.out.println("encoded value is " + new String(bytesEncoded));
// Decode data on other side, by processing encoded data
byte[] valueDecoded = Base64.decodeBase64(bytesEncoded);
System.out.println("Decoded value is " + new String(valueDecoded));
Hope this answers your doubt.
Java 8 now supports BASE64 Encoding and Decoding. You can use the following classes:
java.util.Base64, java.util.Base64.Encoder and java.util.Base64.Decoder.
Example usage:
// encode with padding
String encoded = Base64.getEncoder().encodeToString(someByteArray);
// encode without padding
String encoded = Base64.getEncoder().withoutPadding().encodeToString(someByteArray);
// decode a String
byte [] barr = Base64.getDecoder().decode(encoded);
The accepted answer uses the Apache Commons package but this is how I did it using Java's native libraries
Java 11 and up
import java.util.Base64;
public class Base64Encoding {
public static void main(String[] args) {
Base64.Encoder enc = Base64.getEncoder();
Base64.Decoder dec = Base64.getDecoder();
String str = "77+9x6s=";
// encode data using BASE64
String encoded = enc.encodeToString(str.getBytes());
System.out.println("encoded value is \t" + encoded);
// Decode data
String decoded = new String(dec.decode(encoded));
System.out.println("decoded value is \t" + decoded);
System.out.println("original value is \t" + str);
}
}
Java 6 - 10
import java.io.UnsupportedEncodingException;
import javax.xml.bind.DatatypeConverter;
public class EncodeString64 {
public static void main(String[] args) throws UnsupportedEncodingException {
String str = "77+9x6s=";
// encode data using BASE64
String encoded = DatatypeConverter.printBase64Binary(str.getBytes());
System.out.println("encoded value is \t" + encoded);
// Decode data
String decoded = new String(DatatypeConverter.parseBase64Binary(encoded));
System.out.println("decoded value is \t" + decoded);
System.out.println("original value is \t" + str);
}
}
The better way would be to try/catch the encoding/decoding steps but hopefully you get the idea.
For Spring Users , Spring Security has a Base64 class in the org.springframework.security.crypto.codec package that can also be used for encoding and decoding of Base64.
Ex.
public static String base64Encode(String token) {
byte[] encodedBytes = Base64.encode(token.getBytes());
return new String(encodedBytes, Charset.forName("UTF-8"));
}
public static String base64Decode(String token) {
byte[] decodedBytes = Base64.decode(token.getBytes());
return new String(decodedBytes, Charset.forName("UTF-8"));
}
The following is a good solution -
import android.util.Base64;
String converted = Base64.encodeToString(toConvert.toString().getBytes(), Base64.DEFAULT);
String stringFromBase = new String(Base64.decode(converted, Base64.DEFAULT));
That's it. A single line encoding and decoding.
import javax.xml.bind.DatatypeConverter;
public class f{
public static void main(String a[]){
String str = new String(DatatypeConverter.printBase64Binary(new String("user:123").getBytes()));
String res = DatatypeConverter.parseBase64Binary(str);
System.out.println(res);
}
}
