java 处理图片 Base64

Base64ImageUtil.java

package test;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import javax.xml.bind.DatatypeConverter;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.UUID;

public class Base64ImageUtil {

    /**
     * 图片转BASE64
     *
     * @param imagePath 路径
     * @return
     */
    public static String imageChangeBase64(String imagePath) {
        InputStream inputStream = null;
        byte[] data = null;
        try {
            inputStream = new FileInputStream(imagePath);
            data = new byte[inputStream.available()];
            inputStream.read(data);
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 加密
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data);
    }

    /**
     * BASE转图片
     *
     * @param baseStr   base64字符串
     * @param imagePath 生成的图片
     * @return
     */
    public static boolean base64ChangeImage(String baseStr, String imagePath) {
        if (baseStr == null) {
            return false;
        }
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // 解密
            byte[] b = decoder.decodeBuffer(baseStr);
            // 处理数据
            // 因为byte是有符号的，它表示的范围是-127~127，如果要映射到无符号0~255，那么0~127不用改变，而-128~-1对应128~255。
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }
            OutputStream out = new FileOutputStream(imagePath);
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * 如果上面不好用，就用这个
     * @param baseStr
     * @param imagePath
     */
    public static void base64ChangeImage2(String baseStr, String imagePath) {
        BufferedImage image = null;
        byte[] imageByte = null;

        try {
            imageByte = DatatypeConverter.parseBase64Binary(baseStr);
            ByteArrayInputStream bis = new ByteArrayInputStream(imageByte);
            image = ImageIO.read(new ByteArrayInputStream(imageByte));
            bis.close();

            File outputfile = new File("e:\\sealImg.bmp");
            ImageIO.write(image, "bmp", outputfile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {

        //加密
//        String basestr = imageChangeBase64("D://1.png");
//        System.out.println(basestr);
        //
        String str = "data:image/png;base64,xxxxxxx=="; // 替换成真实的BASE64
        String[] sr = str.split(",");

        String a = sr[0];
        String data = sr[1];
        String imgType = a.substring(a.indexOf('/') + 1, a.indexOf(';'));

        String imgName = UUID.randomUUID().toString().replaceAll("-","");
        String imgPath = "D://" + imgName + "." + imgType;

        //解密
        base64ChangeImage(data,imgPath);
    }

}