How to overwrite file via java nio writer?

Question

I try files writer as follows:

String content = "Test File Content";

• I used as like : Files.write(path, content.getBytes(), StandardOpenOption.CREATE);

If file is not create, file is created and content is written. But If file available , the file content is Test File ContentTest File Content and if the code is run repeat, the file content is Test File ContentTest File ContentTest File Content ...

• I used as like : Files.write(path, content.getBytes(), StandardOpenOption.CREATE_NEW); ,

If file is not create, file is created and than thow an exception as follow:

java.nio.file.FileAlreadyExistsException: /home/gyhot/Projects/indexing/ivt_new/target/test-classes/test_file at sun.nio.fs.UnixException.translateToIOException(UnixException.java:88) at ...

How to overwrite file via java new I/O?

Solution 1

You want to call the method without any OpenOption arguments.

Files.write(path, content.getBytes());

From the Javadoc:

The options parameter specifies how the the file is created or opened. If no options are present then this method works as if the CREATE, TRUNCATE_EXISTING, and WRITE options are present. In other words, it opens the file for writing, creating the file if it doesn't exist, or initially truncating an existing regular-file to a size of 0

Solution 2

You want to use both StandardOpenOption.TRUNCATE_EXISTING and StandardOpenOption.CREATE options together:

Files.write(path, content.getBytes(),
         StandardOpenOption.CREATE,
         StandardOpenOption.TRUNCATE_EXISTING );