项目总结13：Jav文件压缩-InputStream转化为base64-Base64解码并生成图片

Jav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

 package com.hs.common.util.imgecode;

 import com.hs.common.util.Logger;
 import net.coobird.thumbnailator.Thumbnails;
 import org.apache.commons.codec.binary.Base64;
 import sun.misc.BASE64Decoder;

 import javax.imageio.ImageIO;
 import java.awt.image.BufferedImage;
 import java.io.*;

 public class ImageEncodeUtil {
     private final static Logger logger = Logger.getLogger(ImageEncodeUtil.class);

     //1-压缩图片
     public static InputStream  compressFile(InputStream input) throws IOException {
         //1-压缩图片
         BufferedImage bufImg = ImageIO.read(input);// 把图片读入到内存中
         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
         ByteArrayOutputStream bos = new ByteArrayOutputStream();// 存储图片文件byte数组
         ImageIO.write(bufImg, "jpg", bos); // 图片写入到 ImageOutputStream
         input = new ByteArrayInputStream(bos.toByteArray());
         int available = input.available();
         //2-如果大小超过50KB，继续压缩
         if(available > 50000){
             compressFile(input);
         }
         return input;

     }
     //2-InputStream转化为base64
     public static String getBase64FromInputStream(InputStream in) {
         // 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
         byte[] data = null;
         // 读取图片字节数组
         try {
             ByteArrayOutputStream swapStream = new ByteArrayOutputStream();
             byte[] buff = new byte[100];
             int rc = 0;
             while ((rc = in.read(buff, 0, 100)) > 0) {
                 swapStream.write(buff, 0, rc);
             }
             data = swapStream.toByteArray();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             if (in != null) {
                 try {
                     in.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         }
         String str = new String(Base64.encodeBase64(data));
         System.out.println( "str length: " + str.length() + "  str: " + str);
         return str;
     }

     //3-Base64解码并生成图片
     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
         if (base64str == null) //图像数据为空
             return false;
         BASE64Decoder decoder = new BASE64Decoder();
         try {
             //Base64解码
             byte[] b = decoder.decodeBuffer(base64str);
             // 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             }
             //生成jpeg图片
             OutputStream out = new FileOutputStream(savepath);
             out.write(b);
             out.flush();
             out.close();
             return true;
         } catch (Exception e) {
             return false;
         }
     }

         public static void main(String[] args) {
         try {
             File file = new File("C:\\Users\\tyj\\Desktop\\01.jpg");
             FileInputStream fileInputStream = new FileInputStream(file);
             InputStream inputStream = compressFile(fileInputStream);
             String base64FromInputStream = getBase64FromInputStream(inputStream);
             GenerateImage(base64FromInputStream,"C:\\\\Users\\\\tyj\\\\Desktop\\\\113001.jpg");
             InputStream is =new ByteArrayInputStream(base64FromInputStream.getBytes("UTF-8"));
             System.out.println("compress success");
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

 }

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

        <!-- 谷歌图片压缩 -->
        <dependency>
            <groupId>net.coobird</groupId>
            <artifactId>thumbnailator</artifactId>
            <version>0.4.8</version>
        </dependency>

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）