70 lines
2.1 KiB
Java
70 lines
2.1 KiB
Java
package com.mcwl.common.utils;
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/**
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* Base64工具类
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* @author DaiZibo
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* @date 2025/1/16
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* @apiNote
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*/
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public class Base64Util {
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private static final char last2byte = (char) Integer.parseInt("00000011", 2);
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private static final char last4byte = (char) Integer.parseInt("00001111", 2);
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private static final char last6byte = (char) Integer.parseInt("00111111", 2);
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private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
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private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
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private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
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private static final char[] encodeTable = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
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public Base64Util() {
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}
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public static String encode(byte[] from) {
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StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
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int num = 0;
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char currentByte = 0;
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int i;
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for (i = 0; i < from.length; ++i) {
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for (num %= 8; num < 8; num += 6) {
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switch (num) {
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case 0:
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currentByte = (char) (from[i] & lead6byte);
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currentByte = (char) (currentByte >>> 2);
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case 1:
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case 3:
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case 5:
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default:
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break;
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case 2:
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currentByte = (char) (from[i] & last6byte);
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break;
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case 4:
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currentByte = (char) (from[i] & last4byte);
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currentByte = (char) (currentByte << 2);
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if (i + 1 < from.length) {
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currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
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}
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break;
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case 6:
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currentByte = (char) (from[i] & last2byte);
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currentByte = (char) (currentByte << 4);
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if (i + 1 < from.length) {
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currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
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}
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}
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to.append(encodeTable[currentByte]);
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}
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}
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if (to.length() % 4 != 0) {
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for (i = 4 - to.length() % 4; i > 0; --i) {
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to.append("=");
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}
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}
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return to.toString();
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}
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}
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