使用BASE64Decoder完成文件与二进制之间互相转化

怼烎@ 2023-09-30 15:52 37阅读 0赞

import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.OutputStreamWriter;
    import sun.misc.BASE64Decoder;
    import sun.misc.BASE64Encoder;
    
    /**
     \* 使用sun.misc.BASE64Decoder和sun.misc.BASE64Encoder
     \* 完成文件转化二进制之间互相转化
     *
     */
    public class BASE64test {
        
      /**
       *
       \* @param path 目标文件
       \* @param path2 生成文件
       */
      public static void encodeBase64File(String path,String path2) throws Exception {
        
        File file = new File(path);//创建目标文件对象
        FileInputStream inputFile = new FileInputStream(file);//输入流
        FileOutputStream out=new FileOutputStream(path2);//输出流
        OutputStreamWriter osw=new OutputStreamWriter(out);//文字写入流
        //文件读取时未使用缓冲，一次性读取
        byte[] buffer = new byte[(int) file.length()];
        inputFile.read(buffer);
        inputFile.close();
        //new BASE64Encoder().encode(buffer返回String类型的字符串
        //再使用文字输出流将其写出
        osw.write((new BASE64Encoder().encode(buffer)));
        osw.close();
        out.close();
       }
      public static void main(String[] args) {
        
        String path="C:\\Users\\Public\\Pictures\\Sample Pictures\\EAG42EqA_2560x1600.jpg";
        String path1="C:\\Users\\Public\\Pictures\\Sample Pictures\\EAG42EqA_2560x16002.txt";
        try {
        
          encodeBase64File(path,path1);
          File file=new File(path1);
          FileInputStream fis=new FileInputStream(file);
          FileOutputStream fos=new FileOutputStream("C:\\Users\\Public\\Pictures\\Sample Pictures\\EAG42EqA_2560x16003.jpg");
          BASE64Decoder bd=new BASE64Decoder();
          byte[] b=bd.decodeBuffer(fis);
          fos.write(b);
        } catch (Exception e) {
        
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
        
      }
    }

java安装的目录下的jre/lib/rt.jar中有以下两个类实现base64的编码和解码：

sun.misc.BASE64Encoder
    
    sun.misc.BASE64Decoder

下面是java实现：

public class Imagebase64 {
        
        static BASE64Encoder encoder = new sun.misc.BASE64Encoder();
        static BASE64Decoder decoder = new sun.misc.BASE64Decoder();
    
        public static void main(String[] args) {
        
            System.out.println(getImageBinary()); // image to base64
            base64StringToImage(getImageBinary()); // base64 to image
        }
    
        static String getImageBinary() {
        
            File f = new File("d://in.jpg");
            try {
        
                BufferedImage bi = ImageIO.read(f);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ImageIO.write(bi, "jpg", baos);
                byte[] bytes = baos.toByteArray();
    
                return encoder.encodeBuffer(bytes).trim();
            } catch (IOException e) {
        
                e.printStackTrace();
            }
            return null;
        }
    
        static void base64StringToImage(String base64String) {
        
            try {
        
                byte[] bytes1 = decoder.decodeBuffer(base64String);
                ByteArrayInputStream bais = new ByteArrayInputStream(bytes1);
                BufferedImage bi1 = ImageIO.read(bais);
                File f1 = new File("d://out.jpg");
                ImageIO.write(bi1, "jpg", f1);
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }
    }