The algorithm of Base64 encoded in the Java class library and its core implementation principles

The algorithm of Base64 encoded in the Java class library and its core implementation principles Summary: Base64 encoding is a commonly used encoding method that converts binary data into printed characters and is widely used in data transmission and storage.The Java class library provides support for Base64 encoding. This article will introduce the implementation principle of the Base64 encoding algorithm and provide Java code examples to help readers understand. 1. Base64 Code Introduction Base64 encoding is a encoding method that converts binary data into printed characters.It consists of 64 characters, including 26 capital letters, 26 lowercase letters, 10 numbers and two special symbols.The base64 encoding can be used to transmit binary data to a system that does not support binary, and can also be used to store binary data as a text format. 2. The implementation principle of base64 encoding The implementation principle of the base64 encoding is to use 3 bytes (24 bits) as a group and convert it into 4 printed characters.If the number of bytes of the data cannot be divided by 3, 0 bytes will be filled.The process of coding includes the following steps: 1. Divide the input data to a group every 3 bytes. 2. Convert 3 bytes of each group to 4 6 -bit index values. 3. Use an index value to check the table to convert it to the corresponding base64 character. 4. If the input data is not a multiples of 3, the filling operation will be performed, and up to 2 bytes. 5. Comb with 4 BASE64 characters together to get the final base64 encoding result. Third, the tool class of Base64 encoded in the Java class library The Java class library provides the Base64 -encoded tool class java.util.base64, which contains support for Base64 encoding and decoding.The following is an example code that uses the Java class library to use the base64 encoding: import java.util.Base64; public class Base64Example { public static void main(String[] args) { // String to be coded String input = "Hello, World!"; // Perform the base64 encoding of the string String encoded = Base64.getEncoder().encodeToString(input.getBytes()); System.out.println ("Base64 encoding result:" + encoded); // Reverse the base64 encoding results byte[] decoded = Base64.getDecoder().decode(encoded); String decodedString = new String(decoded); System.out.println ("Base64 decoding result:" + decodedstring); } } Run this code will output the following results: Base64 encoding result: SGVSBG8SIFDVCMXKIQ == Base64 decoding result: Hello, World! Fourth, summary This article introduces the algorithm of Base64 in the Java class library and its implementation principles.The base64 encoding is a commonly used encoding method to convert binary data into printed characters. The Java class library provides support of Base64 encoding, which is convenient for developers to transmit and store data.Through learning the principle of Base64 encoding and using the example code of the Java library, readers can better understand and apply base64 encoding.