Base64 encoder and decoder

Is there a base-64 decoder and encoder for a String in Android?

Dan D.

See android.util.Base64

It seems that this was added in API version 8 or android 2.2 so it will not be available on the older platforms.

But the source of it is at android/util/Base64.java so if needed one could just copy it unchanged for older versions.

This is an example of how to use the Base64 class to encode and decode a simple String value.

// String to be encoded with Base64
String text = "Test";
// Sending side
byte[] data = null;
try {
    data = text.getBytes("UTF-8");
} catch (UnsupportedEncodingException e1) {
    e1.printStackTrace();
}
String base64 = Base64.encodeToString(data, Base64.DEFAULT);

// Receiving side
byte[] data1 = Base64.decode(base64, Base64.DEFAULT);
String text1 = null;
try {
    text1 = new String(data1, "UTF-8");
} catch (UnsupportedEncodingException e) {
    e.printStackTrace();
}

This excerpt can be included in an Android activity.

To encode:

private String encodeString(String s) {
    byte[] data = new byte[0];

    try {
        data = s.getBytes("UTF-8");

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } finally {
        String base64Encoded = Base64.encodeToString(data, Base64.DEFAULT);

        return base64Encoded;

    }
}

To decode:

private String decodeString(String encoded) {
    byte[] dataDec = Base64.decode(encoded, Base64.DEFAULT);
    String decodedString = "";
    try {

        decodedString = new String(dataDec, "UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();

    } finally {

        return decodedString;
    }
}

Example

    String text = "example007";

    Log.e("encoded", encodeString(text)); //Output: ZXhhbXBsZTAwNw==
    Log.e("decoded", decodeString(encodeString(text))); //Output: example007

Here is a simple method I was going to use until I realized that this is only supported in Android API 8+:

// Has line break
public String getBase64(String input) {
    return Base64.encodeToString(input.getBytes(), Base64.DEFAULT);
}

// No line break
public String getBase64(String input) {
    return Base64.encodeToString(input.getBytes(), Base64.NO_WRAP);
}

If you don't want a line break at the end of the String, change the flags from Base64.DEFAULT to Base64.NO_WRAP

Base64.encodeToString("yourString".getBytes("UTF-8"), Base64.NO_WRAP);

base64 decode this may help all of us.

来源：https://stackoverflow.com/questions/4322182/base64-encoder-and-decoder

标签

java

android

base64

encoder

decoder