Module java.compiler
Package javax.tools

Interface JavaFileManager

  • All Superinterfaces:
    AutoCloseable, Closeable, Flushable, OptionChecker
    All Known Subinterfaces:
    StandardJavaFileManager
    All Known Implementing Classes:
    ForwardingJavaFileManager

    public interface JavaFileManager
extends Closeable, Flushable, OptionChecker
    File manager for tools operating on Java™ programming language source and class files. In this context, file means an abstraction of regular files and other sources of data.

    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.

    Since:
    1.6
    See Also:
    JavaFileObject, FileObject

    • Method Detail

      • getClassLoader

        ClassLoader getClassLoader​(JavaFileManager.Location ___location)
        Returns a class loader for loading plug-ins from the given package-oriented ___location. For example, to load annotation processors, a compiler will request a class loader for the ANNOTATION_PROCESSOR_PATH ___location.
        Parameters:
        ___location - a ___location
        Returns:
        a class loader for the given ___location; or null if loading plug-ins from the given ___location is disabled or if the ___location is not known
        Throws:
        SecurityException - if a class loader can not be created in the current security context
        IllegalStateException - if close() has been called and this file manager cannot be reopened
        IllegalArgumentException - if the ___location is a module-oriented ___location

      • list

        Iterable<JavaFileObject> list​(JavaFileManager.Location ___location,
                              String packageName,
                              Set<JavaFileObject.Kind> kinds,
                              boolean recurse)
                       throws IOException
        Lists all file objects matching the given criteria in the given package-oriented ___location. List file objects in "subpackages" if recurse is true.

        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.

        Parameters:
        ___location - a ___location
        packageName - a package name
        kinds - return objects only of these kinds
        recurse - if true include "subpackages"
        Returns:
        an Iterable of file objects matching the given criteria
        Throws:
        IOException - if an I/O error occurred, or if close() has been called and this file manager cannot be reopened
        IllegalArgumentException - if the ___location is a module-oriented ___location
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • inferBinaryName

        String inferBinaryName​(JavaFileManager.Location ___location,
                       JavaFileObject file)
        Infers a binary name of a file object based on a package-oriented ___location. The binary name returned might not be a valid binary name according to The Java™ Language Specification.
        Parameters:
        ___location - a ___location
        file - a file object
        Returns:
        a binary name or null the file object is not found in the given ___location
        Throws:
        IllegalArgumentException - if the ___location is a module-oriented ___location
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • isSameFile

        boolean isSameFile​(FileObject a,
                   FileObject b)
        Compares two file objects and return true if they represent the same underlying object.
        Parameters:
        a - a file object
        b - a file object
        Returns:
        true if the given file objects represent the same underlying object
        Throws:
        IllegalArgumentException - if either of the arguments were created with another file manager and this file manager does not support foreign file objects

      • handleOption

        boolean handleOption​(String current,
                     Iterator<String> remaining)
        Handles one option. If current is an option to this file manager it will consume any arguments to that option from remaining and return true, otherwise return false.
        Parameters:
        current - current option
        remaining - remaining options
        Returns:
        true if this option was handled by this file manager, false otherwise
        Throws:
        IllegalArgumentException - if this option to this file manager is used incorrectly
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • hasLocation

        boolean hasLocation​(JavaFileManager.Location ___location)
        Determines if a ___location is known to this file manager.
        Parameters:
        ___location - a ___location
        Returns:
        true if the ___location is known

      • getJavaFileForInput

        JavaFileObject getJavaFileForInput​(JavaFileManager.Location ___location,
                                   String className,
                                   JavaFileObject.Kind kind)
                            throws IOException
        Returns a file object for input representing the specified class of the specified kind in the given package-oriented ___location.
        Parameters:
        ___location - a ___location
        className - the name of a class
        kind - the kind of file, must be one of SOURCE or CLASS
        Returns:
        a file object, might return null if the file does not exist
        Throws:
        IllegalArgumentException - 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 valid, or if the ___location is a module-oriented ___location
        IOException - if an I/O error occurred, or if close() has been called and this file manager cannot be reopened
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • getJavaFileForOutput

        JavaFileObject getJavaFileForOutput​(JavaFileManager.Location ___location,
                                    String className,
                                    JavaFileObject.Kind kind,
                                    FileObject sibling)
                             throws IOException
        Returns a file object for output representing the specified class of the specified kind in the given package-oriented ___location.

        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.

        Parameters:
        ___location - a package-oriented ___location
        className - the name of a class
        kind - 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
        Returns:
        a file object for output
        Throws:
        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 valid, or if the ___location is not an output ___location
        IOException - if an I/O error occurred, or if close() has been called and this file manager cannot be reopened
        IllegalStateException - close() has been called and this file manager cannot be reopened

      • getFileForInput

        FileObject getFileForInput​(JavaFileManager.Location ___location,
                           String packageName,
                           String relativeName)
                    throws IOException
        Returns a file object for input representing the specified relative name in the specified package in the given package-oriented ___location.

        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".

        Parameters:
        ___location - a package-oriented ___location
        packageName - a package name
        relativeName - a relative name
        Returns:
        a file object, might return null if the file does not exist
        Throws:
        IllegalArgumentException - if the ___location is not known to this file manager and the file manager does not support unknown locations, or if relativeName is not valid, or if the ___location is a module-oriented ___location
        IOException - if an I/O error occurred, or if close() has been called and this file manager cannot be reopened
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • getFileForOutput

        FileObject getFileForOutput​(JavaFileManager.Location ___location,
                            String packageName,
                            String relativeName,
                            FileObject sibling)
                     throws IOException
        Returns a file object for output representing the specified relative name in the specified package in the given ___location.

        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.

        Parameters:
        ___location - an output ___location
        packageName - a package name
        relativeName - a relative name
        sibling - a file object to be used as hint for placement; might be null
        Returns:
        a file object
        Throws:
        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 valid, or if the ___location is not an output ___location
        IOException - if an I/O error occurred, or if close() has been called and this file manager cannot be reopened
        IllegalStateException - if close() has been called and this file manager cannot be reopened

      • flush

        void flush​()
    throws IOException
        Flushes any resources opened for output by this file manager directly or indirectly. Flushing a closed file manager has no effect.
        Specified by:
        flush in interface Flushable
        Throws:
        IOException - if an I/O error occurred
        See Also:
        close()

      • close

        void close​()
    throws IOException
        Releases any resources opened by this file manager directly or indirectly. This might render this file manager useless and the effect of subsequent calls to methods on this object or any objects obtained through this object is undefined unless explicitly allowed. However, closing a file manager which has already been closed has no effect.
        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Throws:
        IOException - if an I/O error occurred
        See Also:
        flush()

      • getLocationForModule

        default JavaFileManager.Location getLocationForModule​(JavaFileManager.Location ___location,
                                                      String moduleName)
                                               throws IOException
        Gets a ___location for a named module within a ___location, which may be either a module-oriented ___location or an output ___location. The result will be an output ___location if the given ___location is an output ___location, or it will be a package-oriented ___location.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Parameters:
        ___location - the module-oriented ___location
        moduleName - the name of the module to be found
        Returns:
        the ___location for the named module
        Throws:
        IOException - if an I/O error occurred
        UnsupportedOperationException - if this operation if not supported by this file manager
        IllegalArgumentException - if the ___location is neither an output ___location nor a module-oriented ___location
        Since:
        9

      • getLocationForModule

        default JavaFileManager.Location getLocationForModule​(JavaFileManager.Location ___location,
                                                      JavaFileObject fo)
                                               throws IOException
        Gets a ___location for the module containing a specific file to be found within a ___location, which may be either a module-oriented ___location or an output ___location. The result will be an output ___location if the given ___location is an output ___location, or it will be a package-oriented ___location.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Parameters:
        ___location - the module-oriented ___location
        fo - the file
        Returns:
        the module containing the file
        Throws:
        IOException - if an I/O error occurred
        UnsupportedOperationException - if this operation if not supported by this file manager
        IllegalArgumentException - if the ___location is neither an output ___location nor a module-oriented ___location
        Since:
        9

      • getServiceLoader

        default <S> ServiceLoader<S> getServiceLoader​(JavaFileManager.Location ___location,
                                              Class<S> service)
                                       throws IOException
        Get a service loader for a specific service class from a given ___location. If the ___location is a module-oriented ___location, the service loader will use the service declarations in the modules found in that ___location. Otherwise, a service loader is created using the package-oriented ___location, in which case, the services are determined using the provider-configuration files in META-INF/services.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Type Parameters:
        S - the service class
        Parameters:
        ___location - the module-oriented ___location
        service - the Class object of the service class
        Returns:
        a service loader for the given service class
        Throws:
        IOException - if an I/O error occurred
        UnsupportedOperationException - if this operation if not supported by this file manager
        Since:
        9

      • inferModuleName

        default String inferModuleName​(JavaFileManager.Location ___location)
                        throws IOException
        Infer the name of the module from its ___location, as returned by getLocationForModule or listModuleLocations.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Parameters:
        ___location - a package-oriented ___location representing a module
        Returns:
        the name of the module
        Throws:
        IOException - if an I/O error occurred
        UnsupportedOperationException - if this operation if not supported by this file manager
        IllegalArgumentException - if the ___location is not one known to this file manager
        Since:
        9

      • listLocationsForModules

        default Iterable<Set<JavaFileManager.Location>> listLocationsForModules​(JavaFileManager.Location ___location)
                                                                 throws IOException
        Lists the locations for all the modules in a module-oriented ___location or an output ___location. The locations that are returned will be output locations if the given ___location is an output, or it will be a package-oriented locations.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Parameters:
        ___location - the module-oriented ___location for which to list the modules
        Returns:
        a series of sets of locations containing modules
        Throws:
        IOException - if an I/O error occurred
        UnsupportedOperationException - if this operation if not supported by this file manager
        IllegalArgumentException - if the ___location is not a module-oriented ___location
        Since:
        9

      • contains

        default boolean contains​(JavaFileManager.Location ___location,
                         FileObject fo)
                  throws IOException
        Determines whether or not a given file object is "contained in" a specified ___location.

        For a package-oriented ___location, a file object is contained in the ___location if there exist values for packageName and relativeName such that either of the following calls would return the same file object: 

             getFileForInput(___location, packageName, relativeName)
     getFileForOutput(___location, packageName, relativeName, null)

        For a module-oriented ___location, a file object is contained in the ___location if there exists a module that may be obtained by the call: 

             getLocationForModule(___location, moduleName)
        such that the file object is contained in the (package-oriented) ___location for that module.
        Implementation Requirements:
        This implementation throws UnsupportedOperationException.
        Parameters:
        ___location - the ___location
        fo - the file object
        Returns:
        whether or not the file is contained in the ___location
        Throws:
        IOException - if there is a problem determining the result
        UnsupportedOperationException - if the method is not supported
        Since:
        9