Konvertieren Sie Datei in Byte - Array, dann zu String dann zu Byte - Array dann zu der ursprünglichen Datei

Question

Ich versuche (In Java), um ein Dateidokument dann in BitArray danach zu einem String mit ähnlicher Darstellung, dann zurück zu konvertieren Original-Bit-Array und schließlich zum ursprünglichen Abschlussdokument.

Hier ist mein Code, aber die erzeugte Datei ist in diesem Fall das Bild nicht sichtbar.

try { 
     File file = new File("C:/Users/dkimigho/Downloads/kenyapowerlogo.jpg"); 

     FileInputStream fis = null; 
     try { 
      fis = new FileInputStream(file); 
     } catch (FileNotFoundException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     //create FileInputStream which obtains input bytes from a file in a file system 
     //FileInputStream is meant for reading streams of raw bytes such as image data. For reading streams of characters, consider using FileReader. 

     ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
     byte[] buf = new byte[1024]; 
     try { 
      for (int readNum; (readNum = fis.read(buf)) != -1;) { 
       //Writes to this byte array output stream 
       bos.write(buf, 0, readNum); 
       System.out.println("read " + readNum + " bytes,"); 
      } 
     } catch (IOException ex) { 
      Logger.getLogger(ARRAYBITStoPDF.class.getName()).log(Level.SEVERE, null, ex); 
     } 

     byte[] bytes = bos.toByteArray(); 

     System.out.println("byte1"); 
     for (int i = 0; i < bytes.length; i++) { 
      System.out.print(bytes[i]); 
     } 
     //We have the bytes now convert to String 
     String stringbytearray=new String(bytes); 

     System.out.println("stringbytearray: "+stringbytearray); 

     //We have the bytes now convert to String 

     byte[] content = stringbytearray.getBytes(); 
     System.out.println("byte2"); 
     for (int i = 0; i < content.length; i++) { 
      System.out.print(content[i]); 
     } 

     int size = bytes.length; 
     InputStream isfilecontent = null; 
     byte[] b = new byte[size]; 
     isfilecontent = new ByteArrayInputStream(content); 

     //writing the downloaded data into a PDF file 
     FileOutputStream fileOutputpdf = new FileOutputStream("C:/Users/dkimigho/Downloads/mykenyapowerlogo.jpg"); 

     /* use binary I/O to prevent line based operation messing with the encoding.*/ 
     byte[] buf2 = new byte[2048]; 
     int b_read = 0; 
     while ((b_read = isfilecontent.read(buf2)) > 0) { 
      fileOutputpdf.write(buf2, 0, b_read); 
     } 
     fileOutputpdf.flush(); 
     //closed the output stream 
     fileOutputpdf.close(); 

    } catch (IOException e) { 
     // handle IOException 
     System.out.println(e.getMessage()); 
    } 

Irgendwelche Hilfe auf das Zeigen, was ich falsch mache? Eine Korrektur meines Codes zu einem Arbeitscode kann wichtig sein.

Answer 1

Ich fand eine Antwort man muss JAVA 8 java.util.Base64 verwenden, um die Bytes zu codieren und zu dekodieren, ohne Informationen über das Dokument zu verlieren. Ich hoffe, dass es jemandem helfen wird.

/* 
    * 1. How to convert an image file to byte array? 
    */ 
    try { 
     File file = new File("C:/Users/qwerty/Downloads/factura.pdf"); 

     FileInputStream fis = null; 
     try { 
      fis = new FileInputStream(file); 
     } catch (FileNotFoundException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     //create FileInputStream which obtains input bytes from a file in a file system 
     //FileInputStream is meant for reading streams of raw bytes such as image data. For reading streams of characters, consider using FileReader. 

     ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
     byte[] buf = new byte[1024]; 
     try { 
      for (int readNum; (readNum = fis.read(buf)) != -1;) { 
       //Writes to this byte array output stream 
       bos.write(buf, 0, readNum); 
       // System.out.println("read " + readNum + " bytes,"); 
      } 
     } catch (IOException ex) { 
      Logger.getLogger(ARRAYBITStoPDF.class.getName()).log(Level.SEVERE, null, ex); 
     } 

     byte[] bytes = bos.toByteArray(); 
     bos.close(); // should be inside a finally block 
     //We have the bytes now convert to String 

     // ENCODING 
     String encodedDoc= Base64.getEncoder().encodeToString(bytes); 

     System.out.println(encodedDoc); 

     // DECODING 
     int size = bytes.length; 
     InputStream isfilecontent = null; 
     //byte[] b = new byte[size]; 
     isfilecontent = new ByteArrayInputStream(Base64.getDecoder().decode(encodedDoc)); 

     //writing the downloaded data into a PDF file 
     FileOutputStream fileOutputpdf = new FileOutputStream("C:/Users/qwerty/Downloads/myfactura.pdf"); 

     /* use binary I/O to prevent line based operation messing with the encoding.*/ 
     byte[] buf2 = new byte[2048]; 
     int b_read = 0; 
     while ((b_read = isfilecontent.read(buf2)) > 0) { 
      fileOutputpdf.write(buf2, 0, b_read); 
     } 
     fileOutputpdf.flush(); 
     //closed the output stream 
     fileOutputpdf.close(); 

    } catch (IOException e) { 
     // handle IOException 
     System.out.println(e.getMessage()); 
    }