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）