字节转换工具

╰+哭是因爲堅強的太久メ 2022-05-19 14:36 238阅读 0赞

/**
     * 字节转换工具
     * @author ThinkGem
     * @version 2015-6-20
     */
    public class ByteUtils {
    
        private static final int UNIT = 1024;
    
        /**
         * @param byteSize 字节
         * @return
         */
        public static String formatByteSize(long byteSize) {
    
            double size = 1.0 * byteSize;
    
            String type = "B";
            if((int)Math.floor(size / UNIT) <= 0) { //不足1KB
                type = "B";
                return format(size, type);
            }
    
            size = size / UNIT;
            if((int)Math.floor(size / UNIT) <= 0) { //不足1MB
                type = "KB";
                return format(size, type);
            }
    
            size = size / UNIT;
            if((int)Math.floor(size / UNIT) <= 0) { //不足1GB
                type = "MB";
                return format(size, type);
            }
    
            size = size / UNIT;
            if((int)Math.floor(size / UNIT) <= 0) { //不足1TB
                type = "GB";
                return format(size, type);
            }
    
            size = size / UNIT;
            if((int)Math.floor(size / UNIT) <= 0) { //不足1PB
                type = "TB";
                return format(size, type);
            }
    
            size = size / UNIT;
            if((int)Math.floor(size / UNIT) <= 0) {
                type = "PB";
                return format(size, type);
            }
            return ">PB";
        }
    
        private static String format(double size, String type) {
            int precision = 0;
    
            if(size * 1000 % 10 > 0) {
                precision = 3;
            } else if(size * 100 % 10 > 0) {
                precision = 2;
            } else if(size * 10 % 10 > 0) {
                precision = 1;
            } else {
                precision = 0;
            }
    
            String formatStr = "%." + precision + "f";
    
            if("KB".equals(type)) {
                return String.format(formatStr, (size)) + "KB";
            } else if("MB".equals(type)) {
                return String.format(formatStr, (size)) + "MB";
            } else if("GB".equals(type)) {
                return String.format(formatStr, (size)) + "GB";
            } else if("TB".equals(type)) {
                return String.format(formatStr, (size)) + "TB";
            } else if("PB".equals(type)) {
                return String.format(formatStr, (size)) + "PB";
            }
            return  String.format(formatStr, (size)) + "B";
        }
    
        public static void main(String[] args) {
            System.out.println(ByteUtils.formatByteSize(1023));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * UNIT));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * 1023));
            System.out.println(ByteUtils.formatByteSize(1L * 1023 * 1023 * 1023));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * UNIT * UNIT));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * UNIT * UNIT * UNIT));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * UNIT * UNIT * UNIT * UNIT));
            System.out.println(ByteUtils.formatByteSize(1L * UNIT * UNIT * UNIT * UNIT * UNIT * UNIT));
        }
    
    }