Java文件压缩-InputStream转化为base64-Base64解码并生成图片

直接上源码，解释见文章尾部

  1 package com.hs.common.util.imgecode;
  2 
  3 import com.hs.common.util.Logger;
  4 import net.coobird.thumbnailator.Thumbnails;
  5 import org.apache.commons.codec.binary.Base64;
  6 import sun.misc.BASE64Decoder;
  7 
  8 import javax.imageio.ImageIO;
  9 import java.awt.image.BufferedImage;
 10 import java.io.*;
 11 
 12 
 13 public class ImageEncodeUtil {
 14     private final static Logger logger = Logger.getLogger(ImageEncodeUtil.class);
 15 
 16     //1-压缩图片
 17     public static InputStream  compressFile(InputStream input) throws IOException {
 18         //1-压缩图片
 19         BufferedImage bufImg = ImageIO.read(input);// 把图片读入到内存中
 20         bufImg = Thumbnails.of(bufImg).width(100).keepAspectRatio(true).outputQuality(0.2f).asBufferedImage();//压缩:宽度100px,长度自适应;质量压缩到0.1
 21         ByteArrayOutputStream bos = new ByteArrayOutputStream();// 存储图片文件byte数组
 22         ImageIO.write(bufImg, "jpg", bos); // 图片写入到 ImageOutputStream
 23         input = new ByteArrayInputStream(bos.toByteArray());
 24         int available = input.available();
 25         //2-如果大小超过50KB，继续压缩
 26         if(available > 50000){
 27             compressFile(input);
 28         }
 29         return input;
 30 
 31     }
 32     //2-InputStream转化为base64
 33     public static String getBase64FromInputStream(InputStream in) {
 34         // 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
 35         byte[] data = null;
 36         // 读取图片字节数组
 37         try {
 38             ByteArrayOutputStream swapStream = new ByteArrayOutputStream();
 39             byte[] buff = new byte[100];
 40             int rc = 0;
 41             while ((rc = in.read(buff, 0, 100)) > 0) {
 42                 swapStream.write(buff, 0, rc);
 43             }
 44             data = swapStream.toByteArray();
 45         } catch (IOException e) {
 46             e.printStackTrace();
 47         } finally {
 48             if (in != null) {
 49                 try {
 50                     in.close();
 51                 } catch (IOException e) {
 52                     e.printStackTrace();
 53                 }
 54             }
 55         }
 56         String str = new String(Base64.encodeBase64(data));
 57         System.out.println( "str length: " + str.length() + "  str: " + str);
 58         return str;
 59     }
 60 
 61     //3-Base64解码并生成图片
 62     public static boolean GenerateImage(String base64str,String savepath) { //对字节数组字符串进行Base64解码并生成图片
 63         if (base64str == null) //图像数据为空
 64             return false;
 65         BASE64Decoder decoder = new BASE64Decoder();
 66         try {
 67             //Base64解码
 68             byte[] b = decoder.decodeBuffer(base64str);
 69             // System.out.println("解码完成");
 70             for (int i = 0; i < b.length; ++i) {
 71                 if (b[i] < 0) {//调整异常数据（这一步很重要）
 72                     b[i] += 256;
 73                 }
 74             }
 75             //生成jpeg图片
 76             OutputStream out = new FileOutputStream(savepath);
 77             out.write(b);
 78             out.flush();
 79             out.close();
 80             return true;
 81         } catch (Exception e) {
 82             return false;
 83         }
 84     }
 85 
 86         public static void main(String[] args) {
 87         try {
 88             File file = new File("C:\\Users\\tyj\\Desktop\\01.jpg");
 89             FileInputStream fileInputStream = new FileInputStream(file);
 90             InputStream inputStream = compressFile(fileInputStream);
 91             String base64FromInputStream = getBase64FromInputStream(inputStream);
 92             GenerateImage(base64FromInputStream,"C:\\\\Users\\\\tyj\\\\Desktop\\\\113001.jpg");
 93             InputStream is =new ByteArrayInputStream(base64FromInputStream.getBytes("UTF-8"));
 94             System.out.println("compress success");
 95         } catch (IOException e) {
 96             // TODO Auto-generated catch block
 97             e.printStackTrace();
 98         }
 99     }
100 
101 }

 1.图片压缩使用谷歌thumbnailator，详情可参考：https://www.cnblogs.com/ken-jl/p/8847567.html

        
        
            net.coobird
            thumbnailator
            0.4.8
        

2-InputStream转化为base64

3-Base64解码并生成图片，注意其中的标红部分，调整异常数据（这一步很重要）