Base64字符串与图片的相互转换

本篇博客记载的是一个我们在开发过程中很常用的一个小功能，就是我们在处理图片的时候做数据存放到数据库的功能，我们存放的不再是本地路径而是一个Base64的字符串！

然后我们在取值的时候又将Base64转换为一个图片文件的做法

简单的两个步骤：

一、导入工具类：

Base64Util:

package com.ruoyi.system.controller;import java.io.ByteArrayOutputStream;import java.io.File; import java.io.IOException;import java.util.regex.Matcher;import java.util.regex.Pattern; import javax.imageio.stream.FileImageInputStream; import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder; public class Base64Util{        public static byte[] decode(String base64Str){        byte[] b = null;        BASE64Decoder decoder = new BASE64Decoder();        try {            b = decoder.decodeBuffer(replaceEnter(base64Str));        } catch (IOException e) {            e.printStackTrace();         }        return b;     }        public static String encode(byte[] image){        BASE64Encoder decoder = new BASE64Encoder();        return replaceEnter(decoder.encode(image));    }    public static String encode(String uri){        BASE64Encoder encoder = new BASE64Encoder();        return replaceEnter(encoder.encode(uri.getBytes()));    }         public static byte[] imageTobyte(String path){        byte[] data = null;        FileImageInputStream input = null;        try {            input = new FileImageInputStream(new File(path));            ByteArrayOutputStream output = new ByteArrayOutputStream();            byte[] buf = new byte[1024];            int numBytesRead = 0;            while((numBytesRead = input.read(buf)) != -1){               output.write(buf, 0, numBytesRead);            }             data = output.toByteArray();         output.close();             input.close();         } catch (Exception e) {             e.printStackTrace();         }         return data;    }    public static String replaceEnter(String str){        String reg ="[\n-\r]";        Pattern p = Pattern.compile(reg);        Matcher m = p.matcher(str);        return m.replaceAll("");    } }

ImageUtils:

package com.ruoyi.system.controller;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import javax.imageio.ImageIO;import javax.swing.ImageIcon;import java.awt.Graphics;import java.awt.GraphicsConfiguration;import java.awt.GraphicsDevice;import java.awt.GraphicsEnvironment;import java.awt.HeadlessException;import java.awt.Image;import java.awt.Toolkit;import java.awt.Transparency;import java.net.HttpURLConnection;import java.net.URL;public class ImageUtils {    public static String getBase64ByImgUrl(String url){        String suffix = url.substring(url.lastIndexOf(".") + 1);        try {            URL urls = new URL(url);            ByteArrayOutputStream  baos = new ByteArrayOutputStream();            Image image = Toolkit.getDefaultToolkit().getImage(urls);            BufferedImage  biOut = toBufferedImage(image);            ImageIO.write(biOut, suffix, baos);            String base64Str = Base64Util.encode(String.valueOf(baos.toByteArray()));            return base64Str;        } catch (Exception e) {            return "";        }    }    public static BufferedImage toBufferedImage(Image image) {        if (image instanceof BufferedImage) {            return (BufferedImage) image;        }        // This code ensures that all the pixels in the image are loaded        image = new ImageIcon(image).getImage();        BufferedImage bimage = null;        GraphicsEnvironment ge = GraphicsEnvironment                .getLocalGraphicsEnvironment();        try {            int transparency = Transparency.OPAQUE;            GraphicsDevice gs = ge.getDefaultScreenDevice();            GraphicsConfiguration GC = gs.getDefaultConfiguration();            bimage = gc.createCompatibleImage(image.getWidth(null),                    image.getHeight(null), transparency);        } catch (HeadlessException e) {            // The system does not have a screen        }        if (bimage == null) {            // Create a buffered image using the default color model            int type = BufferedImage.TYPE_INT_RGB;            bimage = new BufferedImage(image.getWidth(null),                    image.getHeight(null), type);        }        // Copy image to buffered image        Graphics g = bimage.createGraphics();        // Paint the image onto the buffered image        g.drawImage(image, 0, 0, null);        g.dispose();        return bimage;    }        public static String image2Base64(String imgUrl) {        URL url = null;        InputStream is = null;        ByteArrayOutputStream outStream = null;        HttpURLConnection httpUrl = null;        try{            url = new URL(imgUrl);            httpUrl = (HttpURLConnection) url.openConnection();            httpUrl.connect();            httpUrl.getInputStream();            is = httpUrl.getInputStream();            outStream = new ByteArrayOutputStream();            //创建一个Buffer字符串            byte[] buffer = new byte[1024];            //每次读取的字符串长度，如果为-1，代表全部读取完毕            int len = 0;            //使用一个输入流从buffer里把数据读取出来            while( (len=is.read(buffer)) != -1 ){                //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度                outStream.write(buffer, 0, len);            }            // 对字节数组Base64编码            return Base64Util.encode(outStream.toByteArray());        }catch (Exception e) {            e.printStackTrace();        }        finally{            if(is != null)            {                try {                    is.close();                } catch (IOException e) {                    e.printStackTrace();                }            }            if(outStream != null)            {                try {                    outStream.close();                } catch (IOException e) {                    e.printStackTrace();                }            }            if(httpUrl != null)            {                httpUrl.disconnect();            }        }        return imgUrl;    }}

二、使用方式：

使用方式非常简单就是调用ImageUtils方法中的方法即可：

例如：我们使用图片转换Base64就直接传入一张图片的路径即可：

来源地址：https://blog.csdn.net/weixin_66110079/article/details/127862404