Base 64 encode and decode example code

Does anyone know how to decode and encode a string in Base64 using the Base64. I am using the following code, but it's not working.

String source = "password"; byte[] byteArray = source.getBytes("UTF-16"); Base64 bs = new Base64(); //bs.encodeBytes(byteArray); System.out.println( bs.encodeBytes(byteArray)); //bs.decode(bs.encodeBytes(byteArray)); System.out.println(bs.decode(bs.encodeBytes(byteArray))); 

14 Answers

First:

• Choose an encoding. UTF-8 is generally a good choice; stick to an encoding which will definitely be valid on both sides. It would be rare to use something other than UTF-8 or UTF-16.

Transmitting end:

• Encode the string to bytes (e.g. text.getBytes(encodingName))
• Encode the bytes to base64 using the Base64 class
• Transmit the base64

Receiving end:

• Receive the base64
• Decode the base64 to bytes using the Base64 class
• Decode the bytes to a string (e.g. new String(bytes, encodingName))

So something like:

// Sending side byte[] data = text.getBytes("UTF-8"); String base64 = Base64.encodeToString(data, Base64.DEFAULT); // Receiving side byte[] data = Base64.decode(base64, Base64.DEFAULT); String text = new String(data, "UTF-8"); 

Or with StandardCharsets:

// Sending side byte[] data = text.getBytes(StandardCharsets.UTF_8); String base64 = Base64.encodeToString(data, Base64.DEFAULT); // Receiving side byte[] data = Base64.decode(base64, Base64.DEFAULT); String text = new String(data, StandardCharsets.UTF_8); 

For Kotlin mb better to use this:

fun String.decode(): String { return Base64.decode(this, Base64.DEFAULT).toString(charset("UTF-8")) } fun String.encode(): String { return Base64.encodeToString(this.toByteArray(charset("UTF-8")), Base64.DEFAULT) } 

Example:

Log.d("LOGIN", "TEST") Log.d("LOGIN", "TEST".encode()) Log.d("LOGIN", "TEST".encode().decode()) 

To anyone else who ended up here while searching for info on how to decode a string encoded with Base64.encodeBytes(), here was my solution:

// encode String ps = "techPass"; String tmp = Base64.encodeBytes(ps.getBytes()); // decode String ps2 = "dGVjaFBhC3M="; byte[] tmp2 = Base64.decode(ps2); String val2 = new String(tmp2, "UTF-8"); 

Also, I'm supporting older versions of Android so I'm using Robert Harder's Base64 library from

If you are using Kotlin than use like this

For Encode

val password = "Here Your String" val data = password.toByteArray(charset("UTF-8")) val base64 = Base64.encodeToString(data, Base64.DEFAULT) 

For Decode

val datasd = Base64.decode(base64, Base64.DEFAULT) val text = String(datasd, charset("UTF-8")) 

something like

String source = "password"; byte[] byteArray; try { byteArray = source.getBytes("UTF-16"); System.out.println(new String(Base64.decode(Base64.encode(byteArray, Base64.DEFAULT), Base64.DEFAULT))); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } 

To encrypt:

byte[] encrpt= text.getBytes("UTF-8"); String base64 = Base64.encodeToString(encrpt, Base64.DEFAULT); 

To decrypt:

byte[] decrypt= Base64.decode(base64, Base64.DEFAULT); String text = new String(decrypt, "UTF-8"); 

Above many answers but doesn't work for me some of them no exception handling in correct way. here am adding a perfect solution work amazing for me sure also for you too.

//base64 decode string String s = "ewoic2VydmVyIjoic2cuenhjLmx1IiwKInNuaSI6InRlc3RpbmciLAoidXNlcm5hbWUiOiJ0ZXN0 ZXIiLAoicGFzc3dvcmQiOiJ0ZXN0ZXIiLAoicG9ydCI6IjQ0MyIKfQ=="; String val = a(s) ; Toast.makeText(this, ""+val, Toast.LENGTH_SHORT).show(); public static String a(String str) { try { return new String(Base64.decode(str, 0), "UTF-8"); } catch (UnsupportedEncodingException | IllegalArgumentException unused) { return "This is not a base64 data"; } } 

Based on the previous answers I'm using the following utility methods in case anyone would like to use it.

 /** * @param message the message to be encoded * * @return the enooded from of the message */ public static String toBase64(String message) { byte[] data; try { data = message.getBytes("UTF-8"); String base64Sms = Base64.encodeToString(data, Base64.DEFAULT); return base64Sms; } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return null; } /** * @param message the encoded message * * @return the decoded message */ public static String fromBase64(String message) { byte[] data = Base64.decode(message, Base64.DEFAULT); try { return new String(data, "UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return null; } 

For API level 26+

String encodedString = Base64.getEncoder().encodeToString(byteArray); 

Ref: (byte[])

'java.util.Base64' class provides functionality to encode and decode the information in Base64 format.

How to get Base64 Encoder?

Encoder encoder = Base64.getEncoder(); 

How to get Base64 Decoder?

Decoder decoder = Base64.getDecoder(); 

How to encode the data?

Encoder encoder = Base64.getEncoder(); String originalData = "java"; byte[] encodedBytes = encoder.encode(originalData.getBytes()); 

How to decode the data?

Decoder decoder = Base64.getDecoder(); byte[] decodedBytes = decoder.decode(encodedBytes); String decodedStr = new String(decodedBytes); 

You can get more details at this link.

Answer from 2021 in kotlin

Encode :

 val data: String = "Hello" val dataByteArray: ByteArray = data.toByteArray() val dataInBase64: String = Base64Utils.encode(dataByteArray) 

Decode :

 val dataInBase64: String = "..." val dataByteArray: ByteArray = Base64Utils.decode(dataInBase64) val data: String = dataByteArray.toString() 

package net.itempire.virtualapp; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Base64; import android.view.View; import android.widget.EditText; import android.widget.TextView; public class BaseActivity extends AppCompatActivity { EditText editText; TextView textView; TextView textView2; TextView textView3; TextView textView4; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_base); editText=(EditText)findViewById(R.id.edt); textView=(TextView) findViewById(R.id.tv1); textView2=(TextView) findViewById(R.id.tv2); textView3=(TextView) findViewById(R.id.tv3); textView4=(TextView) findViewById(R.id.tv4); textView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { textView2.setText(Base64.encodeToString(editText.getText().toString().getBytes(),Base64.DEFAULT)); } }); textView3.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { textView4.setText(new String(Base64.decode(textView2.getText().toString(),Base64.DEFAULT))); } }); } } 

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="" xmlns:app="" xmlns:tools="" android:layout_width="match_parent" android:orientation="vertical" android:layout_height="match_parent" tools:context=".BaseActivity"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/edt" android:paddingTop="30dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tv1" android:text="Encode" android:textSize="20dp" android:padding="20dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tv2" android:textSize="20dp" android:padding="20dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tv3" android:text="decode" android:textSize="20dp" android:padding="20dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tv4" android:textSize="20dp" android:padding="20dp" /> </LinearLayout> 

for android API byte[] to Base64String encoder

byte[] data=new byte[]; String Base64encodeString=android.util.Base64.encodeToString(data, android.util.Base64.DEFAULT);