FileObject (Java SE 26 & JDK 26)
Description: declaration: module: java.compiler, package: javax.tools, interface: FileObject
Keywords: javax.tools.FileObject interface

# Interface FileObject

All Known Subinterfaces:
  `JavaFileObject`

All Known Implementing Classes:
  `ForwardingFileObject, ForwardingJavaFileObject, SimpleJavaFileObject`

public interface FileObject
File abstraction for tools. In this context, file means an abstraction of regular files and other sources of data. For example, a file object can be used to represent regular files, memory cache, or data in databases.

Unless explicitly allowed, all methods in this interface might throw a NullPointerException if given a `null` argument.

Since:
  1.6

- ## Method Summary

  Modifier and Type
  Method
  Description
  `boolean`
  `delete()`
  Deletes this file object.
  `CharSequence`
  `getCharContent(boolean ignoreEncodingErrors)`
  Returns the character content of this file object, if available.
  `long`
  `getLastModified()`
  Returns the time this file object was last modified.
  `String`
  `getName()`
  Returns a user-friendly name for this file object.
  `InputStream`
  `openInputStream()`
  Returns an InputStream for this file object.
  `OutputStream`
  `openOutputStream()`
  Returns an OutputStream for this file object.
  `Reader`
  `openReader(boolean ignoreEncodingErrors)`
  Returns a reader for this object.
  `Writer`
  `openWriter()`
  Returns a Writer for this file object.
  `URI`
  `toUri()`
  Returns a URI identifying this file object.

- ## Method Details

  - ### toUri

    URI toUri()
    Returns a URI identifying this file object.
    Returns:
      a URI

  - ### getName

    String getName()
    Returns a user-friendly name for this file object. The exact value returned is not specified but implementations should take care to preserve names as given by the user. For example, if the user writes the filename `"BobsApp\Test.java"` on the command line, this method should return `"BobsApp\Test.java"` whereas the toUri method might return `file:///C:/Documents%20and%20Settings/UncleBob/BobsApp/Test.java`.
    Returns:
      a user-friendly name

  - ### openInputStream

    InputStream openInputStream() throws IOException
    Returns an InputStream for this file object.
    Returns:
      an InputStream
    Throws:
      `IllegalStateException` - if this file object was opened for writing and does not support reading
      `UnsupportedOperationException` - if this kind of file object does not support byte access
      `IOException` - if an I/O error occurred

  - ### openOutputStream

    OutputStream openOutputStream() throws IOException
    Returns an OutputStream for this file object.
    Returns:
      an OutputStream
    Throws:
      `IllegalStateException` - if this file object was opened for reading and does not support writing
      `UnsupportedOperationException` - if this kind of file object does not support byte access
      `IOException` - if an I/O error occurred

  - ### openReader

    Reader openReader(boolean ignoreEncodingErrors) throws IOException
    Returns a reader for this object. The returned reader will replace bytes that cannot be decoded with the default translation character. In addition, the reader may report a diagnostic unless `ignoreEncodingErrors` is true.
    Parameters:
      `ignoreEncodingErrors` - ignore encoding errors if true
    Returns:
      a Reader
    Throws:
      `IllegalStateException` - if this file object was opened for writing and does not support reading
      `UnsupportedOperationException` - if this kind of file object does not support character access
      `IOException` - if an I/O error occurred

  - ### getCharContent

    CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException
    Returns the character content of this file object, if available. Any byte that cannot be decoded will be replaced by the default translation character. In addition, a diagnostic may be reported unless `ignoreEncodingErrors` is true.
    Parameters:
      `ignoreEncodingErrors` - ignore encoding errors if true
    Returns:
      a CharSequence if available; `null` otherwise
    Throws:
      `IllegalStateException` - if this file object was opened for writing and does not support reading
      `UnsupportedOperationException` - if this kind of file object does not support character access
      `IOException` - if an I/O error occurred

  - ### openWriter

    Writer openWriter() throws IOException
    Returns a Writer for this file object.
    Returns:
      a Writer
    Throws:
      `IllegalStateException` - if this file object was opened for reading and does not support writing
      `UnsupportedOperationException` - if this kind of file object does not support character access
      `IOException` - if an I/O error occurred

  - ### getLastModified

    long getLastModified()
    Returns the time this file object was last modified. The time is measured in milliseconds since the epoch (00:00:00 GMT, January 1, 1970).
    Returns:
      the time this file object was last modified; or 0 if the file object does not exist, if an I/O error occurred, or if the operation is not supported

  - ### delete

    boolean delete()
    Deletes this file object. In case of errors, returns false.
    Returns:
      true if and only if this file object is successfully deleted; false otherwise