来自 imageView 的 Java Fx 图像更新

Question

how to update image showing in imageView i set this image from database code to get image on imageView from db is...

InputStream is = resultSet.getBinaryStream("image");
OutputStream os;

os = new FileOutputStream(new File("src/sources/images/photo.jpg"));
byte[]content = new byte[1024];
int size = 0;
while((size=is.read(content))!= -1)
{
   os.write(content,0,size);
}
os.close();
is.close();
image  = new Image("file:src/sources/images/photo.jpg");

imageView.setImage(image);

image is saving in BLOB type in MySQL database

Now i want to update this image and set it again this image if i dont choose any image using file chooser please solve my this problem thanks in advance

File chooser code

stage = (Stage) showScene.getScene().getWindow();

   file = fileChooser.showOpenDialog(stage);

   if(file != null){
               image = new Image(file.getAbsoluteFile().toURI().toString(),imageView.getFitWidth(),imageView.getFitHeight(),true,true);
       imageView.setImage(image);
       imageView.setPreserveRatio(true);
   }
  fis = new FileInputStream(file); // here i got error(null pointer exception) if i try to update withouting choosing image from filechooser 

I pass fis to the preparedstatement to update and also insert

Answer 1

You are getting a NullPointerException because if you don't choose a file with the FileChooser, your file variable is set to null. This can be resolved by altering your if statement a little.

file = fileChooser.showOpenDialog(stage);

if (file == null) {
    file = new File("path/to/default/file")
}

image = new Image(file.getAbsoluteFile().toURI().toString(),imageView.getFitWidth(),imageView.getFitHeight(),true,true);
imageView.setImage(image);
imageView.setPreserveRatio(true);

fis = new FileInputStream(file);