Preserve file last modified date time while copying it from source to target

Question

I am trying to copy a file from one location to another. While copying it from source to target, target file is taking current date time. How can i make target file date as same as source file.

FileInputStream source = new FileInputStream("D:\\test\\test.txt");
OutputStream target = new FileOutputStream("D:\\test.txt");
byte[] buffer = new byte[source.available()];
source.read(buffer);
target.write(buffer);
source.close();
target.close();`

Answer 1

This is provided by the java.io.File class. You need to create an instance of it first and pass it to the streams:

File input = new File("D:\\test\\test.txt");
File output = new File("D:\\test.txt");
try( FileInputStream source = new FileInputStream(input);
     OutputStream target = new FileOutputStream(output)){
    byte[] buffer = new byte[source.available()];
    source.read(buffer);
    target.write(buffer);
}
long modified = input.lastModified();
output.setLastModified(modified);

BTW: I assume you use at least Java 7, so I changed your code to use the try-with-resources feature. This is strongly recommended since it also takes care of closing resources in case an exception is raised.