JDK14/Java14源码在线阅读
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package javax.tools;
import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.util.Iterator;
import java.util.ServiceLoader;
import java.util.Set;
import static javax.tools.JavaFileObject.Kind;
/**
* File manager for tools operating on Java™ programming language
* source and class files. In this context, <em>file</em> means an
* abstraction of regular files and other sources of data.
*
* <p>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.
*
* <p>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
* <cite>The Java™ Virtual Machine Specification</cite>.
* <blockquote><p>
* <i>Discussion:</i> 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
* <cite>The Java™ Language Specification</cite>,
* section 13.1 "The Form of a Binary".
* </p></blockquote>
*
* <p>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 {@link
* java.io.File#getCanonicalFile} or similar means. If the system is
* not case-aware, file objects must use other means to preserve case.
*
* <p><em><a id="relative_name">Relative names</a>:</em> 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 <a
* href="http://www.ietf.org/rfc/rfc3986.txt">RFC 3986</a>,
* section 3.3. Informally, this should be true:
*
* <!-- URI.create(relativeName).normalize().getPath().equals(relativeName) -->
* <pre> URI.{@linkplain java.net.URI#create create}(relativeName).{@linkplain java.net.URI#normalize normalize}().{@linkplain java.net.URI#getPath getPath}().equals(relativeName)</pre>
*
* <p>All methods in this interface might throw a SecurityException.
*
* <p>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.
*
* <p><em>Implementation note:</em> a consequence of this requirement
* is that a trivial implementation of output to a {@linkplain
* java.util.jar.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.
*
* <p>Unless explicitly allowed, all methods in this interface might
* throw a NullPointerException if given a {@code null} argument.
*
* @author Peter von der Ahé
* @author Jonathan Gibbons
* @see JavaFileObject
* @see FileObject
* @since 1.6
*/
public interface JavaFileManager extends Closeable, Flushable, OptionChecker {
/**
* Interface for locations of file objects. Used by file managers
* to determine where to place or search for file objects.
*
* <p>Informally, a {@code Location} corresponds to a "search path", such as a class
* path or module path, as used by command-line tools that use the default file system.
*
* <p>Some locations are typically used to identify a place in which
* a tool can find files to be read; others are typically used to identify
* a place where a tool can write files. If a location is used to identify
* a place for reading files, those files may be organized in a simple
* <em>package/class</em> hierarchy: such locations are described as
* <strong>package-oriented</strong>.
* Alternatively, the files may be organized in a <em>module/package/class</em>
* hierarchy: such locations are described as <strong>module-oriented</strong>.
* If a location is typically used to identify a place where a tool can write files,
* it is up to the tool that writes the files to specify how those files will be
* organized.
*
* <p>You can access the classes in a package-oriented location using methods like
* {@link JavaFileManager#getJavaFileForInput} or {@link JavaFileManager#list}.
* It is not possible to directly list the classes in a module-oriented
* location. Instead, you can get a package-oriented location for any specific module
* using methods like {@link JavaFileManager#getLocationForModule} or
* {@link JavaFileManager#listLocationsForModules}.
*/
interface Location {
/**
* Returns the name of this location.
*
* @return a name
*/
String getName();
/**
* Determines if this is an output location.
* An output location is a location that is conventionally used for
* output.
*
* @apiNote An output location may be used to write files in either
* a package-oriented organization or in a module-oriented organization.
*
* @return true if this is an output location, false otherwise
*/
boolean isOutputLocation();
/**
* Indicates if this location is module-oriented location, and therefore
* expected to contain classes in a <em>module/package/class</em>
* hierarchy, as compared to a package-oriented location, which
* is expected to contain classes in a <em>package/class</em> hierarchy.
* The result of this method is undefined if this is an output
* location.
*
* @implNote This implementation returns true if the name includes
* the word "MODULE".
*
* @return true if this location is expected to contain modules
* @since 9
* @spec JPMS
*/
default boolean isModuleOrientedLocation() {
return getName().matches("\\bMODULE\\b");
}
}
/**
* 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 {@link
* StandardLocation#ANNOTATION_PROCESSOR_PATH
* ANNOTATION_PROCESSOR_PATH} location.
*
* @param location a location
* @return a class loader for the given location; or {@code 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
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
* @throws IllegalArgumentException if the location is a module-oriented location
*/
ClassLoader getClassLoader(Location location);
/**
* Lists all file objects matching the given criteria in the given
* package-oriented location.
* List file objects in "subpackages" if recurse is true.
*
* <p>Note: even if the given location is unknown to this file
* manager, it may not return {@code null}. Also, an unknown
* location may not cause an exception.
*
* @param location a location
* @param packageName a package name
* @param kinds return objects only of these kinds
* @param recurse if true include "subpackages"
* @return an Iterable of file objects matching the given criteria
* @throws IOException if an I/O error occurred, or if {@link
* #close} has been called and this file manager cannot be
* reopened
* @throws IllegalArgumentException if the location is a module-oriented location
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
Iterable<JavaFileObject> list(Location location,
String packageName,
Set<Kind> kinds,
boolean recurse)
throws IOException;
/**
* 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
* <cite>The Java™ Language Specification</cite>.
*
* @param location a location
* @param file a file object
* @return a binary name or {@code null} the file object is not
* found in the given location
* @throws IllegalArgumentException if the location is a module-oriented location
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
String inferBinaryName(Location location, JavaFileObject file);
/**
* Compares two file objects and return true if they represent the
* same underlying object.
*
* @param a a file object
* @param b a file object
* @return 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
*/
boolean isSameFile(FileObject a, FileObject b);
/**
* Handles one option. If {@code current} is an option to this
* file manager it will consume any arguments to that option from
* {@code remaining} and return true, otherwise return false.
*
* @param current current option
* @param remaining remaining options
* @return true if this option was handled by this file manager,
* false otherwise
* @throws IllegalArgumentException if this option to this file
* manager is used incorrectly
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
boolean handleOption(String current, Iterator<String> remaining);
/**
* Determines if a location is known to this file manager.
*
* @param location a location
* @return true if the location is known
*/
boolean hasLocation(Location location);
/**
* Returns a {@linkplain JavaFileObject file object} for input
* representing the specified class of the specified kind in the
* given package-oriented location.
*
* @param location a location
* @param className the name of a class
* @param kind the kind of file, must be one of {@link
* JavaFileObject.Kind#SOURCE SOURCE} or {@link
* JavaFileObject.Kind#CLASS CLASS}
* @return a file object, might return {@code 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
* @throws IOException if an I/O error occurred, or if {@link
* #close} has been called and this file manager cannot be
* reopened
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
JavaFileObject getJavaFileForInput(Location location,
String className,
Kind kind)
throws IOException;
/**
* Returns a {@linkplain JavaFileObject file object} for output
* representing the specified class of the specified kind in the
* given package-oriented location.
*
* <p>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.
*
* @param location a package-oriented location
* @param className the name of a class
* @param kind the kind of file, must be one of {@link
* JavaFileObject.Kind#SOURCE SOURCE} or {@link
* JavaFileObject.Kind#CLASS CLASS}
* @param sibling a file object to be used as hint for placement;
* might be {@code null}
* @return 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
* @throws IOException if an I/O error occurred, or if {@link
* #close} has been called and this file manager cannot be
* reopened
* @throws IllegalStateException {@link #close} has been called
* and this file manager cannot be reopened
*/
JavaFileObject getJavaFileForOutput(Location location,
String className,
Kind kind,
FileObject sibling)
throws IOException;
/**
* Returns a {@linkplain FileObject file object} for input
* representing the specified <a href="JavaFileManager.html#relative_name">relative
* name</a> in the specified package in the given package-oriented location.
*
* <p>If the returned object represents a {@linkplain
* JavaFileObject.Kind#SOURCE source} or {@linkplain
* JavaFileObject.Kind#CLASS class} file, it must be an instance
* of {@link JavaFileObject}.
*
* <p>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 {@linkplain
* StandardLocation#SOURCE_PATH SOURCE_PATH} location, this method
* might be called like so:
*
* <pre>getFileForInput(SOURCE_PATH, "com.sun.tools.javac", "resources/compiler.properties");</pre>
*
* <p>If the call was executed on Windows, with SOURCE_PATH set to
* <code>"C:\Documents and Settings\UncleBob\src\share\classes"</code>,
* a valid result would be a file object representing the file
* <code>"C:\Documents and Settings\UncleBob\src\share\classes\com\sun\tools\javac\resources\compiler.properties"</code>.
*
* @param location a package-oriented location
* @param packageName a package name
* @param relativeName a relative name
* @return a file object, might return {@code 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 {@code relativeName} is not valid,
* or if the location is a module-oriented location
* @throws IOException if an I/O error occurred, or if {@link
* #close} has been called and this file manager cannot be
* reopened
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
FileObject getFileForInput(Location location,
String packageName,
String relativeName)
throws IOException;
/**
* Returns a {@linkplain FileObject file object} for output
* representing the specified <a href="JavaFileManager.html#relative_name">relative
* name</a> in the specified package in the given location.
*
* <p>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.
*
* <p>If the returned object represents a {@linkplain
* JavaFileObject.Kind#SOURCE source} or {@linkplain
* JavaFileObject.Kind#CLASS class} file, it must be an instance
* of {@link JavaFileObject}.
*
* <p>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 {@link
* #getFileForInput getFileForInput} for an example.
*
* @param location an output location
* @param packageName a package name
* @param relativeName a relative name
* @param sibling a file object to be used as hint for placement;
* might be {@code null}
* @return 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 {@code relativeName} is not valid,
* or if the location is not an output location
* @throws IOException if an I/O error occurred, or if {@link
* #close} has been called and this file manager cannot be
* reopened
* @throws IllegalStateException if {@link #close} has been called
* and this file manager cannot be reopened
*/
FileObject getFileForOutput(Location location,
String packageName,
String relativeName,
FileObject sibling)
throws IOException;
/**
* Flushes any resources opened for output by this file manager
* directly or indirectly. Flushing a closed file manager has no
* effect.
*
* @throws IOException if an I/O error occurred
* @see #close
*/
@Override
void flush() 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.
*
* @throws IOException if an I/O error occurred
* @see #flush
*/
@Override
void close() 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.
*
* @implSpec This implementation throws {@code UnsupportedOperationException}.
*
* @param location the module-oriented location
* @param moduleName the name of the module to be found
* @return the location for the named module
*
* @throws IOException if an I/O error occurred
* @throws UnsupportedOperationException if this operation if not supported by this file manager
* @throws IllegalArgumentException if the location is neither an output location nor a
* module-oriented location
* @since 9
* @spec JPMS
*/ // TODO: describe failure modes
default Location getLocationForModule(Location location, String moduleName) throws IOException {
throw new UnsupportedOperationException();
}
/**
* 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.
*
* @implSpec This implementation throws {@code UnsupportedOperationException}.
*
* @param location the module-oriented location
* @param fo the file
* @return the module containing the file
*
* @throws IOException if an I/O error occurred
* @throws UnsupportedOperationException if this operation if not supported by this file manager
* @throws IllegalArgumentException if the location is neither an output location nor a
* module-oriented location
* @since 9
* @spec JPMS
*/
default Location getLocationForModule(Location location, JavaFileObject fo) throws IOException {
throw new UnsupportedOperationException();
}
/**
* 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 {@code META-INF/services}.
*
* @implSpec This implementation throws {@code UnsupportedOperationException}.
*
* @param location the module-oriented location
* @param service the {@code Class} object of the service class
* @param <S> the service class
* @return a service loader for the given service class
*
* @throws IOException if an I/O error occurred
* @throws UnsupportedOperationException if this operation if not supported by this file manager
* @since 9
* @spec JPMS
*/ // TODO: describe failure modes
default <S> ServiceLoader<S> getServiceLoader(Location location, Class<S> service) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Infer the name of the module from its location, as returned by
* {@code getLocationForModule} or {@code listModuleLocations}.
*
* @implSpec This implementation throws {@code UnsupportedOperationException}.
*
* @param location a package-oriented location representing a module
* @return the name of the module
*
* @throws IOException if an I/O error occurred
* @throws UnsupportedOperationException if this operation if not supported by this file manager
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