FileObject (Java Platform SE 8 )
Keywords: javax.tools.FileObject interface
Date: 2026-04-24

compact3
javax.tools

## 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.

  All methods in this interface might throw a SecurityException if a security exception occurs.

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

  Since:
    1.6

- - ### Method Summary

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

- - ### Method Detail

    - #### toUri

          URI toUri()

      Returns a URI identifying this file object.
      Returns:
        a URI

    - #### getName

          String getName()

      Gets 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

      Gets 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

      Gets 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

      Gets 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

      Gets 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

      Gets 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()

      Gets 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

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