Analysis of the technical principles of the "BASE64" framework in the Java class library

The "Base64" framework in the Java class library is a common method for coding and decoding binary data.In network communication and data storage, binary data often needs to be converted into printed string forms for transmission or storage, and the base64 encoding is a commonly used implementation method. Base64 encodes a 64 -character character set, which includes these characters, including lettuce letters, numbers, and two special characters.The principle of the base64 encoding is to divide the binary data of the three bytes into four six -bit groups and convert each six -bit group into corresponding characters.If the data is less than three bytes, the supplementary character (usually '=') is used during the encoding process for filling.In this way, after the binary data of any length is converted into base64 encoding, the length of the result string obtained is always 4/3 times the length of the original data (take it up). In the Java class library, the operation of Base64 encoding and decoding is very simple.It can be operated through the class of java.util.base64.Before the Java 8, you can also use the Base64 in the Sun.MISC kit to encode and decoding, but it has been abandoned in the subsequent version. The following is an example of encoding and decoding using Base64 in the Java class library: import java.util.Base64; public class Base64Example { public static void main(String[] args) { String Originaldata = "Hello World! Hello, the world!"; // base64 encoding String encodedData = Base64.getEncoder().encodeToString(originalData.getBytes()); System.out.println ("Base64 encoded data:" + Encodeddata); // base64 decoding byte[] decodedBytes = Base64.getDecoder().decode(encodedData); String decodedData = new String(decodedBytes); System.out.println ("Base64 decoding data:" + decodeddata); } } The above code first defines a raw data string `" Hello World! Hello, the world! "`.Then use the `Base64.Getencoder (). Encodetostring () method encodes the original data for the base64, obtain the coded string, and print the output.Then use the `Base64.getDecoder (). Decode ()` method to decode the encoded string to obtain the byte array, and convert the byte array to a string through the `new string () method, and finally print output and decoding decoding.Later data. Run the above code, you can see the output result as follows: Base64 encoded data: SGVSBG8GV29YBGQH5L2G5AW977ym5liw55wm77ym Base64 decoding data: Hello World! Hello, world! It can be seen that after the base64 encoding and decoding, the content of the original data can be retained correctly.This is the basic principle of Base64 encoding and how to use the Java class library.