the variable filename2 is only assigned to the last file in the directory.I want to loop through each file in the directory.

Question

// get Names of image files in the knowledge base':
String absolutePath = "C:/Write"; File dir = new File(absolutePath);
File[] filesInDir = dir.listFiles();
for(File file:filesInDir) {
ImageIO.read(file);
filename2 = file.getPath();
}
int ret;
ret = compareFeature(filename1, filename2);
if (ret > 0) { System.out.println(" Image Match found.");
} else {
ImageIO.write((RenderedImage) image, "jpg", new File("C:/Write/"+ filename));
System.out.println(" Image Match not found.");
}

Answer 1

for(File file: filesInDir){
filename2 = file.getPath();
}

--> filename2 = first file, filename2 = second file, ... filename2 = last file --> end loop

If you want all files you can use a list or an array.