package com.emr.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * @ClassName FileUtils
 * @Description 判断是否伟tif图片
 * @Author linjj
 * @Date 2023/4/20 11:15
 * @Version 1.0
 */
public class FileUtils {

    public static final String TYPE_JPG = "jpg";
    public static final String TYPE_GIF = "gif";
    public static final String TYPE_PNG = "png";
    public static final String TYPE_BMP = "bmp";
    public static final String TYPE_TIF ="tif";
    public static final String TYPE_UNKNOWN = "unknown";

    /**
     *
     * @description: 根据文件流判断图片类型
     * @author: Jeff
     * @date: 2019年12月7日
     * @param fis 文件输入流
     * @return
     */
    public static String getPicType(FileInputStream fis) {
        // 读取文件的前几个字节来判断图片格式
        byte[] b = new byte[4];
        try {
            fis.read(b, 0, b.length);
            String type = bytesToHexString(b).toUpperCase();
            if (type.contains("FFD8FF")) {
                return TYPE_JPG;
            } else if (type.contains("89504E47")) {
                return TYPE_PNG;
            } else if (type.contains("47494638")) {
                return TYPE_GIF;
            } else if (type.contains("424D")) {
                return TYPE_BMP;
            } else if (type.contains("49492A00")){
                return TYPE_TIF;
            }
            else {
                return TYPE_UNKNOWN;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

    /**
     *
     * @description: byte数组转换成16进制字符串
     * @author: Jeff
     * @date: 2019年12月7日
     * @param src
     * @return
     */
    public static String bytesToHexString(byte[] src) {
        StringBuilder stringBuilder = new StringBuilder();
        if (src == null || src.length <= 0) {
            return null;
        }
        for (int i = 0; i < src.length; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }

    public static void main(String[] args) {
        try {
            System.out.println("图片1格式： " + getPicType(new FileInputStream(new File("D:\\tmp\\002454.jpg"))));
//            System.out.println("图片2格式： " + getPicType(new FileInputStream(new File("F:\\Jeff\\images\\1.png"))));
//            System.out.println("图片3格式： " + getPicType(new FileInputStream(new File("F:\\Jeff\\images\\2.gif"))));
//            System.out.println("图片4格式： " + getPicType(new FileInputStream(new File("F:\\Jeff\\images\\3.bmp"))));
//            System.out.println("图片5格式： " + getPicType(new FileInputStream(new File("F:\\Jeff\\images\\jie.png"))));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

}
