1 /*
2 * Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
62 * @since 1.0
63 */
64 public
65 class FileInputStream extends InputStream
66 {
67 /* File Descriptor - handle to the open file */
68 private final FileDescriptor fd;
69
70 /**
71 * The path of the referenced file
72 * (null if the stream is created with a file descriptor)
73 */
74 private final String path;
75
76 private volatile FileChannel channel;
77
78 private final Object closeLock = new Object();
79
80 private volatile boolean closed;
81
82 private final Object altFinalizer;
83
84 /**
85 * Creates a <code>FileInputStream</code> by
86 * opening a connection to an actual file,
87 * the file named by the path name <code>name</code>
88 * in the file system. A new <code>FileDescriptor</code>
89 * object is created to represent this file
90 * connection.
91 * <p>
92 * First, if there is a security
93 * manager, its <code>checkRead</code> method
94 * is called with the <code>name</code> argument
95 * as its argument.
96 * <p>
97 * If the named file does not exist, is a directory rather than a regular
98 * file, or for some other reason cannot be opened for reading then a
99 * <code>FileNotFoundException</code> is thrown.
100 *
101 * @param name the system-dependent file name.
102 * @exception FileNotFoundException if the file does not exist,
103 * is a directory rather than a regular file,
138 * <code>checkRead</code> method denies read access to the file.
139 * @see java.io.File#getPath()
140 * @see java.lang.SecurityManager#checkRead(java.lang.String)
141 */
142 public FileInputStream(File file) throws FileNotFoundException {
143 String name = (file != null ? file.getPath() : null);
144 SecurityManager security = System.getSecurityManager();
145 if (security != null) {
146 security.checkRead(name);
147 }
148 if (name == null) {
149 throw new NullPointerException();
150 }
151 if (file.isInvalid()) {
152 throw new FileNotFoundException("Invalid file path");
153 }
154 fd = new FileDescriptor();
155 fd.attach(this);
156 path = name;
157 open(name);
158 altFinalizer = getFinalizer(this);
159 if (altFinalizer == null) {
160 FileCleanable.register(fd); // open set the fd, register the cleanup
161 }
162 }
163
164 /**
165 * Creates a <code>FileInputStream</code> by using the file descriptor
166 * <code>fdObj</code>, which represents an existing connection to an
167 * actual file in the file system.
168 * <p>
169 * If there is a security manager, its <code>checkRead</code> method is
170 * called with the file descriptor <code>fdObj</code> as its argument to
171 * see if it's ok to read the file descriptor. If read access is denied
172 * to the file descriptor a <code>SecurityException</code> is thrown.
173 * <p>
174 * If <code>fdObj</code> is null then a <code>NullPointerException</code>
175 * is thrown.
176 * <p>
177 * This constructor does not throw an exception if <code>fdObj</code>
178 * is {@link java.io.FileDescriptor#valid() invalid}.
179 * However, if the methods are invoked on the resulting stream to attempt
180 * I/O on the stream, an <code>IOException</code> is thrown.
181 *
182 * @param fdObj the file descriptor to be opened for reading.
183 * @throws SecurityException if a security manager exists and its
184 * <code>checkRead</code> method denies read access to the
185 * file descriptor.
186 * @see SecurityManager#checkRead(java.io.FileDescriptor)
187 */
188 public FileInputStream(FileDescriptor fdObj) {
189 SecurityManager security = System.getSecurityManager();
190 if (fdObj == null) {
191 throw new NullPointerException();
192 }
193 if (security != null) {
194 security.checkRead(fdObj);
195 }
196 fd = fdObj;
197 path = null;
198 altFinalizer = null;
199
200 /*
201 * FileDescriptor is being shared by streams.
202 * Register this stream with FileDescriptor tracker.
203 */
204 fd.attach(this);
205 }
206
207 /**
208 * Opens the specified file for reading.
209 * @param name the name of the file
210 */
211 private native void open0(String name) throws FileNotFoundException;
212
213 // wrap native call to allow instrumentation
214 /**
215 * Opens the specified file for reading.
216 * @param name the name of the file
217 */
218 private void open(String name) throws FileNotFoundException {
420 false, false, this);
421 if (closed) {
422 try {
423 // possible race with close(), benign since
424 // FileChannel.close is final and idempotent
425 fc.close();
426 } catch (IOException ioe) {
427 throw new InternalError(ioe); // should not happen
428 }
429 }
430 }
431 }
432 }
433 return fc;
434 }
435
436 private static native void initIDs();
437
438 static {
439 initIDs();
440 }
441
442 /**
443 * Ensures that the {@link #close} method of this file input stream is
444 * called when there are no more references to it.
445 * The {@link #finalize} method does not call {@link #close} directly.
446 *
447 * @apiNote
448 * To release resources used by this stream {@link #close} should be called
449 * directly or by try-with-resources.
450 *
451 * @implSpec
452 * If this FileInputStream has been subclassed and the {@link #close}
453 * method has been overridden, the {@link #close} method will be
454 * called when the FileInputStream is unreachable.
455 * Otherwise, it is implementation specific how the resource cleanup described in
456 * {@link #close} is performed.
457 *
458 * @deprecated The {@code finalize} method has been deprecated and will be removed.
459 * Subclasses that override {@code finalize} in order to perform cleanup
460 * should be modified to use alternative cleanup mechanisms and
461 * to remove the overriding {@code finalize} method.
462 * When overriding the {@code finalize} method, its implementation must explicitly
463 * ensure that {@code super.finalize()} is invoked as described in {@link Object#finalize}.
464 * See the specification for {@link Object#finalize()} for further
465 * information about migration options.
466 *
467 * @exception IOException if an I/O error occurs.
468 * @see java.io.FileInputStream#close()
469 */
470 @Deprecated(since="9", forRemoval = true)
471 protected void finalize() throws IOException {
472 }
473
474 /*
475 * Returns a finalizer object if the FIS needs a finalizer; otherwise null.
476 * If the FIS has a close method; it needs an AltFinalizer.
477 */
478 private static Object getFinalizer(FileInputStream fis) {
479 Class<?> clazz = fis.getClass();
480 while (clazz != FileInputStream.class) {
481 try {
482 clazz.getDeclaredMethod("close");
483 return new AltFinalizer(fis);
484 } catch (NoSuchMethodException nsme) {
485 // ignore
486 }
487 clazz = clazz.getSuperclass();
488 }
489 return null;
490 }
491 /**
492 * Class to call {@code FileInputStream.close} when finalized.
493 * If finalization of the stream is needed, an instance is created
494 * in its constructor(s). When the set of instances
495 * related to the stream is unreachable, the AltFinalizer performs
496 * the needed call to the stream's {@code close} method.
497 */
498 static class AltFinalizer {
499 private final FileInputStream fis;
500
501 AltFinalizer(FileInputStream fis) {
502 this.fis = fis;
503 }
504
505 @Override
506 @SuppressWarnings("deprecation")
507 protected final void finalize() {
508 try {
509 if ((fis.fd != null) && (fis.fd != FileDescriptor.in)) {
510 /* if fd is shared, the references in FileDescriptor
511 * will ensure that finalizer is only called when
512 * safe to do so. All references using the fd have
513 * become unreachable. We can call close()
514 */
515 fis.close();
516 }
517 } catch (IOException ioe) {
518 // ignore
519 }
520 }
521 }
522 }
|
1 /*
2 * Copyright (c) 1994, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
62 * @since 1.0
63 */
64 public
65 class FileInputStream extends InputStream
66 {
67 /* File Descriptor - handle to the open file */
68 private final FileDescriptor fd;
69
70 /**
71 * The path of the referenced file
72 * (null if the stream is created with a file descriptor)
73 */
74 private final String path;
75
76 private volatile FileChannel channel;
77
78 private final Object closeLock = new Object();
79
80 private volatile boolean closed;
81
82 /**
83 * Creates a <code>FileInputStream</code> by
84 * opening a connection to an actual file,
85 * the file named by the path name <code>name</code>
86 * in the file system. A new <code>FileDescriptor</code>
87 * object is created to represent this file
88 * connection.
89 * <p>
90 * First, if there is a security
91 * manager, its <code>checkRead</code> method
92 * is called with the <code>name</code> argument
93 * as its argument.
94 * <p>
95 * If the named file does not exist, is a directory rather than a regular
96 * file, or for some other reason cannot be opened for reading then a
97 * <code>FileNotFoundException</code> is thrown.
98 *
99 * @param name the system-dependent file name.
100 * @exception FileNotFoundException if the file does not exist,
101 * is a directory rather than a regular file,
136 * <code>checkRead</code> method denies read access to the file.
137 * @see java.io.File#getPath()
138 * @see java.lang.SecurityManager#checkRead(java.lang.String)
139 */
140 public FileInputStream(File file) throws FileNotFoundException {
141 String name = (file != null ? file.getPath() : null);
142 SecurityManager security = System.getSecurityManager();
143 if (security != null) {
144 security.checkRead(name);
145 }
146 if (name == null) {
147 throw new NullPointerException();
148 }
149 if (file.isInvalid()) {
150 throw new FileNotFoundException("Invalid file path");
151 }
152 fd = new FileDescriptor();
153 fd.attach(this);
154 path = name;
155 open(name);
156 FileCleanable.register(fd); // open set the fd, register the cleanup
157 }
158
159 /**
160 * Creates a <code>FileInputStream</code> by using the file descriptor
161 * <code>fdObj</code>, which represents an existing connection to an
162 * actual file in the file system.
163 * <p>
164 * If there is a security manager, its <code>checkRead</code> method is
165 * called with the file descriptor <code>fdObj</code> as its argument to
166 * see if it's ok to read the file descriptor. If read access is denied
167 * to the file descriptor a <code>SecurityException</code> is thrown.
168 * <p>
169 * If <code>fdObj</code> is null then a <code>NullPointerException</code>
170 * is thrown.
171 * <p>
172 * This constructor does not throw an exception if <code>fdObj</code>
173 * is {@link java.io.FileDescriptor#valid() invalid}.
174 * However, if the methods are invoked on the resulting stream to attempt
175 * I/O on the stream, an <code>IOException</code> is thrown.
176 *
177 * @param fdObj the file descriptor to be opened for reading.
178 * @throws SecurityException if a security manager exists and its
179 * <code>checkRead</code> method denies read access to the
180 * file descriptor.
181 * @see SecurityManager#checkRead(java.io.FileDescriptor)
182 */
183 public FileInputStream(FileDescriptor fdObj) {
184 SecurityManager security = System.getSecurityManager();
185 if (fdObj == null) {
186 throw new NullPointerException();
187 }
188 if (security != null) {
189 security.checkRead(fdObj);
190 }
191 fd = fdObj;
192 path = null;
193
194 /*
195 * FileDescriptor is being shared by streams.
196 * Register this stream with FileDescriptor tracker.
197 */
198 fd.attach(this);
199 }
200
201 /**
202 * Opens the specified file for reading.
203 * @param name the name of the file
204 */
205 private native void open0(String name) throws FileNotFoundException;
206
207 // wrap native call to allow instrumentation
208 /**
209 * Opens the specified file for reading.
210 * @param name the name of the file
211 */
212 private void open(String name) throws FileNotFoundException {
414 false, false, this);
415 if (closed) {
416 try {
417 // possible race with close(), benign since
418 // FileChannel.close is final and idempotent
419 fc.close();
420 } catch (IOException ioe) {
421 throw new InternalError(ioe); // should not happen
422 }
423 }
424 }
425 }
426 }
427 return fc;
428 }
429
430 private static native void initIDs();
431
432 static {
433 initIDs();
434 }
435 }
|