将二进制数据转换为图像

Question

         FileInputStream is;
    FileOutputStream out;
    byte[] data = new byte[1024];
    int readBytes = 0;

    try {
        is = new FileInputStream(filePath);
        out = new FileOutputStream("C:/Users/gopir/Desktop/me1Copy.jpeg");
        while ((readBytes = is.read(data)) > 0) {
              out.write(data,0,readBytes);
            }
        out.flush();
        out.close();
        is.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }   catch (IOException e) {
        e.printStackTrace();
    }

我只是想将图像转换为二进制，二进制转换为图像。图像到二进制转换工作。为了检查完整性，我只是尝试将二进制数据转换为图像。它创建空图像文件。这段代码有什么问题？

还有其他办法吗？我对使用apache common等外部jar不感兴趣。

修改

这就是我创建二进制文件的方式

                File imageFile = new File(pathName); // Any file Path
        BufferedInputStream bis = null; // To read the given file
        BufferedWriter bw = null; //To write the binary equivalent of the file contents
        String outputFile = "C:\\Users\\gopir\\Desktop\\file1.txt"; // output file name

        try {
            bw = new BufferedWriter(new FileWriter(outputFile)); //Output writer stream
            bis = new BufferedInputStream(new FileInputStream(imageFile)); // Input file reader stream
            int read;
            String text;
            while((read = bis.read()) != -1){ // read 
                text = Integer.toString(read,2); // convert to string
                while (text.length() < 8) { // if length less than 8, prepend 0's
                    text="0"+text;
                }
                bw.write(text); //write it to a file
            }
               bis.close();
                bw.close();
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }