我在将字符串转换为图像时遇到了一个问题。转换字符串图像后，它说文件格式无效。

public class FileExample {

    public static void main(String[] args) throws IOException {
        File file = new File("G:\\designpatterns\\image002.jpg");
        FileInputStream fis = new FileInputStream("G:\\designpatterns\\image002.jpg");
        byte bytes[]= new byte[(int)file.length()];
        fis.read(bytes);
        String rawString = new String(bytes);
        
          FileOutputStream fos = new
          FileOutputStream("G:\\designpatterns\\image001.jpg");
          fos.write(rawString.getBytes()); 
          fis.close();
          fos.close();

    }

}