How Do I Encode and Decode Strings Using Base64 in Java?

Decoding and Encoding Strings Using Base64

In Java, the Base64 class provides methods for encoding and decoding strings in Base64. This representation is commonly used for securely transmitting data over networks or storing it in databases. Here's how to use the Base64 class effectively:

Encoding Strings:

1. Encode the string to bytes using UTF-8.
2. Pass the bytes into the Base64.encodeBytes() method.
3. The result is a byte array, which you can then convert to a string using the Base64.encodeToString() method.

Decoding Strings:

1. Decode the Base64 string back into a byte array using the Base64.decode() method.
2. Decode the bytes into a string using UTF-8.

Example:

To encode and decode the string "password" using Base64:

// Encoding
byte[] byteArray = "password".getBytes("UTF-8");
String encodedString = Base64.encodeToString(byteArray, Base64.DEFAULT);

// Decoding
byte[] decodedByteArray = Base64.decode(encodedString, Base64.DEFAULT);
String decodedString = new String(decodedByteArray, "UTF-8");

Note that the DEFAULT parameter in Base64.encodeToString() and Base64.decode() sets the encoding to Base64.DEFAULT, which is a standard implementation.

Troubleshooting:

If you encounter any errors while using the Base64 class, ensure that you:

1. Have chosen an appropriate character encoding (e.g., UTF-8) when converting strings to/from bytes.
2. Are using the correct method for encoding (encodeBytes() for bytes, encodeToString() for strings) and decoding (decode()).
3. Consult the Java documentation for the Base64 class for detailed usage and troubleshooting information.

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