Java判断上传图片格式的实例代码

   //判断是否是JPG格式
   log.info("-1----进入JPG格式判断.....");
   ImageInputStream iis = ImageIO.createImageInputStream(file.getInputStream());
   Iterator iter = ImageIO.getImageReaders(iis);
   if (!iter.hasNext()) {
     throw new RuntimeException("No readers found!");
   }
   ImageReader reader = iter.next();
   
   log.info("Format1: " + reader.getFormatName()); //这里会打印出图片的格式
   if(!"JPEG".equals(reader.getFormatName())){
     return new ResponseBean(ResponseBean.FAIL, "不支持修改后缀名为jpg的图片");
   }
   iis.close();

package com.metro.crm.util;
import java.io.FileInputStream;
public class FileType{
  public static String bytesToHexString(byte[] src) {
    StringBuilder stringBuilder = new StringBuilder();
    if (src == null || src.length <= 0) {
      return null;
    }
    for (int i = 0; i