public interface JavaFileManager extends Closeable, Flushable, OptionChecker
When constructing new JavaFileObjects, the file manager must determine where to create them. For example, if a file manager manages regular files on a file system, it would most likely have a current/working directory to use as default location when creating or finding files. A number of hints can be provided to a file manager as to where to create files. Any file manager might choose to ignore these hints.
Some methods in this interface use class names. Such class names must be given in the Java Virtual Machine internal form of fully qualified class and interface names. For convenience '.' and '/' are interchangeable. The internal form is defined in chapter four of The Java™ Virtual Machine Specification.
Discussion: this means that the names "java/lang.package-info", "java/lang/package-info", "java.lang.package-info", are valid and equivalent. Compare to binary name as defined in The Java™ Language Specification, section 13.1 "The Form of a Binary".
The case of names is significant. All names should be treated
as case-sensitive. For example, some file systems have
case-insensitive, case-aware file names. File objects representing
such files should take care to preserve case by using File.getCanonicalFile()
or similar means. If the system is
not case-aware, file objects must use other means to preserve case.
Relative names: some methods in this interface use relative names. A relative name is a non-null, non-empty sequence of path segments separated by '/'. '.' or '..' are invalid path segments. A valid relative name must match the "path-rootless" rule of RFC 3986, section 3.3. Informally, this should be true:
URI.create(relativeName).normalize().getPath().equals(relativeName)
All methods in this interface might throw a SecurityException.
An object of this interface is not required to support multi-threaded access, that is, be synchronized. However, it must support concurrent access to different file objects created by this object.
Implementation note: a consequence of this requirement is that a trivial implementation of output to a JarOutputStream is not a sufficient implementation. That is, rather than creating a JavaFileObject that returns the JarOutputStream directly, the contents must be cached until closed and then written to the JarOutputStream.
Unless explicitly allowed, all methods in this interface might
throw a NullPointerException if given a null
argument.
JavaFileObject
,
FileObject
Modifier and Type | Interface and Description |
---|---|
static interface |
JavaFileManager.Location
Interface for locations of file objects.
|
Modifier and Type | Method and Description |
---|---|
void |
close()
Releases any resources opened by this file manager directly or
indirectly.
|
void |
flush()
Flushes any resources opened for output by this file manager
directly or indirectly.
|
ClassLoader |
getClassLoader(JavaFileManager.Location location)
Gets a class loader for loading plug-ins from the given
location.
|
FileObject |
getFileForInput(JavaFileManager.Location location,
String packageName,
String relativeName)
Gets a file object for input
representing the specified relative
name in the specified package in the given location.
|
FileObject |
getFileForOutput(JavaFileManager.Location location,
String packageName,
String relativeName,
FileObject sibling)
Gets a file object for output
representing the specified relative
name in the specified package in the given location.
|
JavaFileObject |
getJavaFileForInput(JavaFileManager.Location location,
String className,
JavaFileObject.Kind kind)
Gets a file object for input
representing the specified class of the specified kind in the
given location.
|
JavaFileObject |
getJavaFileForOutput(JavaFileManager.Location location,
String className,
JavaFileObject.Kind kind,
FileObject sibling)
Gets a file object for output
representing the specified class of the specified kind in the
given location.
|
boolean |
handleOption(String current,
Iterator<String> remaining)
Handles one option.
|
boolean |
hasLocation(JavaFileManager.Location location)
Determines if a location is known to this file manager.
|
String |
inferBinaryName(JavaFileManager.Location location,
JavaFileObject file)
Infers a binary name of a file object based on a location.
|
boolean |
isSameFile(FileObject a,
FileObject b)
Compares two file objects and return true if they represent the
same underlying object.
|
Iterable<JavaFileObject> |
list(JavaFileManager.Location location,
String packageName,
Set<JavaFileObject.Kind> kinds,
boolean recurse)
Lists all file objects matching the given criteria in the given
location.
|
isSupportedOption
ClassLoader getClassLoader(JavaFileManager.Location location)
ANNOTATION_PROCESSOR_PATH
location.location
- a locationnull
if loading plug-ins from the given location is disabled or if
the location is not knownSecurityException
- if a class loader can not be created
in the current security contextIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedIterable<JavaFileObject> list(JavaFileManager.Location location, String packageName, Set<JavaFileObject.Kind> kinds, boolean recurse) throws IOException
Note: even if the given location is unknown to this file
manager, it may not return null
. Also, an unknown
location may not cause an exception.
location
- a locationpackageName
- a package namekinds
- return objects only of these kindsrecurse
- if true include "subpackages"IOException
- if an I/O error occurred, or if close()
has been called and this file manager cannot be
reopenedIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedString inferBinaryName(JavaFileManager.Location location, JavaFileObject file)
location
- a locationfile
- a file objectnull
the file object is not
found in the given locationIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedboolean isSameFile(FileObject a, FileObject b)
a
- a file objectb
- a file objectIllegalArgumentException
- if either of the arguments
were created with another file manager and this file manager
does not support foreign file objectsboolean handleOption(String current, Iterator<String> remaining)
current
is an option to this
file manager it will consume any arguments to that option from
remaining
and return true, otherwise return false.current
- current optionremaining
- remaining optionsIllegalArgumentException
- if this option to this file
manager is used incorrectlyIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedboolean hasLocation(JavaFileManager.Location location)
location
- a locationJavaFileObject getJavaFileForInput(JavaFileManager.Location location, String className, JavaFileObject.Kind kind) throws IOException
location
- a locationclassName
- the name of a classkind
- the kind of file, must be one of SOURCE
or CLASS
null
if the
file does not existIllegalArgumentException
- if the location is not known
to this file manager and the file manager does not support
unknown locations, or if the kind is not validIOException
- if an I/O error occurred, or if close()
has been called and this file manager cannot be
reopenedIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedJavaFileObject getJavaFileForOutput(JavaFileManager.Location location, String className, JavaFileObject.Kind kind, FileObject sibling) throws IOException
Optionally, this file manager might consider the sibling as a hint for where to place the output. The exact semantics of this hint is unspecified. The JDK compiler, javac, for example, will place class files in the same directories as originating source files unless a class file output directory is provided. To facilitate this behavior, javac might provide the originating source file as sibling when calling this method.
location
- a locationclassName
- the name of a classkind
- the kind of file, must be one of SOURCE
or CLASS
sibling
- a file object to be used as hint for placement;
might be null
IllegalArgumentException
- if sibling is not known to
this file manager, or if the location is not known to this file
manager and the file manager does not support unknown
locations, or if the kind is not validIOException
- if an I/O error occurred, or if close()
has been called and this file manager cannot be
reopenedIllegalStateException
- close()
has been called
and this file manager cannot be reopenedFileObject getFileForInput(JavaFileManager.Location location, String packageName, String relativeName) throws IOException
If the returned object represents a source or class file, it must be an instance
of JavaFileObject
.
Informally, the file object returned by this method is located in the concatenation of the location, package name, and relative name. For example, to locate the properties file "resources/compiler.properties" in the package "com.sun.tools.javac" in the SOURCE_PATH location, this method might be called like so:
getFileForInput(SOURCE_PATH, "com.sun.tools.javac", "resources/compiler.properties");
If the call was executed on Windows, with SOURCE_PATH set to
"C:\Documents and Settings\UncleBob\src\share\classes"
,
a valid result would be a file object representing the file
"C:\Documents and Settings\UncleBob\src\share\classes\com\sun\tools\javac\resources\compiler.properties"
.
location
- a locationpackageName
- a package namerelativeName
- a relative namenull
if the file
does not existIllegalArgumentException
- if the location is not known
to this file manager and the file manager does not support
unknown locations, or if relativeName
is not validIOException
- if an I/O error occurred, or if close()
has been called and this file manager cannot be
reopenedIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedFileObject getFileForOutput(JavaFileManager.Location location, String packageName, String relativeName, FileObject sibling) throws IOException
Optionally, this file manager might consider the sibling as a hint for where to place the output. The exact semantics of this hint is unspecified. The JDK compiler, javac, for example, will place class files in the same directories as originating source files unless a class file output directory is provided. To facilitate this behavior, javac might provide the originating source file as sibling when calling this method.
If the returned object represents a source or class file, it must be an instance
of JavaFileObject
.
Informally, the file object returned by this method is
located in the concatenation of the location, package name, and
relative name or next to the sibling argument. See getFileForInput
for an example.
location
- a locationpackageName
- a package namerelativeName
- a relative namesibling
- a file object to be used as hint for placement;
might be null
IllegalArgumentException
- if sibling is not known to
this file manager, or if the location is not known to this file
manager and the file manager does not support unknown
locations, or if relativeName
is not validIOException
- if an I/O error occurred, or if close()
has been called and this file manager cannot be
reopenedIllegalStateException
- if close()
has been called
and this file manager cannot be reopenedvoid flush() throws IOException
flush
in interface Flushable
IOException
- if an I/O error occurredclose()
void close() throws IOException
close
in interface AutoCloseable
close
in interface Closeable
IOException
- if an I/O error occurredflush()
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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