Java compact1, compact2, compact3 java.nio.file Enum StandardOpenOption（JDK8）

Enum Constant Detail

• READ

  public static final StandardOpenOption READ

  Open for read access.

• WRITE

  public static final StandardOpenOption WRITE

  Open for write access.

• APPEND

  public static final StandardOpenOption APPEND

  If the file is opened for WRITE access then bytes will be written to the end of the file rather than the beginning.

  If the file is opened for write access by other programs, then it is file system specific if writing to the end of the file is atomic.

• TRUNCATE_EXISTING

  public static final StandardOpenOption TRUNCATE_EXISTING

  If the file already exists and it is opened for WRITE access, then its length is truncated to 0. This option is ignored if the file is opened only for READ access.

• CREATE

  public static final StandardOpenOption CREATE

  Create a new file if it does not exist. This option is ignored if the CREATE_NEW option is also set. The check for the existence of the file and the creation of the file if it does not exist is atomic with respect to other file system operations.

• CREATE_NEW

  public static final StandardOpenOption CREATE_NEW

  Create a new file, failing if the file already exists. The check for the existence of the file and the creation of the file if it does not exist is atomic with respect to other file system operations.

• DELETE_ON_CLOSE

  public static final StandardOpenOption DELETE_ON_CLOSE

  Delete on close. When this option is present then the implementation makes a best effort attempt to delete the file when closed by the appropriate close method. If the close method is not invoked then a best effort attempt is made to delete the file when the Java virtual machine terminates (either normally, as defined by the Java Language Specification, or where possible, abnormally). This option is primarily intended for use with work files that are used solely by a single instance of the Java virtual machine. This option is not recommended for use when opening files that are open concurrently by other entities. Many of the details as to when and how the file is deleted are implementation specific and therefore not specified. In particular, an implementation may be unable to guarantee that it deletes the expected file when replaced by an attacker while the file is open. Consequently, security sensitive applications should take care when using this option.

  For security reasons, this option may imply the LinkOption.NOFOLLOW_LINKS option. In other words, if the option is present when opening an existing file that is a symbolic link then it may fail (by throwing IOException).

• SPARSE

  public static final StandardOpenOption SPARSE

  Sparse file. When used with the CREATE_NEW option then this option provides a hint that the new file will be sparse. The option is ignored when the file system does not support the creation of sparse files.

• SYNC

  public static final StandardOpenOption SYNC

  Requires that every update to the file's content or metadata be written synchronously to the underlying storage device.

  See Also:

  Synchronized I/O file integrity

• DSYNC

  public static final StandardOpenOption DSYNC

  Requires that every update to the file's content be written synchronously to the underlying storage device.

  See Also:

  Synchronized I/O file integrity

Method Detail

• values

  public static StandardOpenOption[] values()

  Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

  for (StandardOpenOption c : StandardOpenOption.values())
      System.out.println(c);
  

  Returns:

  an array containing the constants of this enum type, in the order they are declared

• valueOf

  public static StandardOpenOption valueOf(String name)

  Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

  Parameters:

  name - the name of the enum constant to be returned.

  Returns:

  the enum constant with the specified name

  Throws:

  IllegalArgumentException - if this enum type has no constant with the specified name

  NullPointerException - if the argument is null