Showing the changes to java/pkg/java/util/zip/CheckedInputStream.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,116 @@ | ||
| 1 | +/* | |
| 2 | + * Copyright (c) 1996, 2006, 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 | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | +package java.util.zip; | |
| 27 | + | |
| 28 | +import java.io.FilterInputStream; | |
| 29 | +import java.io.InputStream; | |
| 30 | +import java.io.IOException; | |
| 31 | + | |
| 32 | +/** | |
| 33 | + * An input stream that also maintains a checksum of the data being read. | |
| 34 | + * The checksum can then be used to verify the integrity of the input data. | |
| 35 | + * | |
| 36 | + * @see Checksum | |
| 37 | + * @author David Connelly | |
| 38 | + */ | |
| 39 | +public | |
| 40 | +class CheckedInputStream extends FilterInputStream { | |
| 41 | + private Checksum cksum; | |
| 42 | + | |
| 43 | + /** | |
| 44 | + * Creates an input stream using the specified Checksum. | |
| 45 | + * @param in the input stream | |
| 46 | + * @param cksum the Checksum | |
| 47 | + */ | |
| 48 | + public CheckedInputStream(InputStream in, Checksum cksum) { | |
| 49 | + super(in); | |
| 50 | + this.cksum = cksum; | |
| 51 | + } | |
| 52 | + | |
| 53 | + /** | |
| 54 | + * Reads a byte. Will block if no input is available. | |
| 55 | + * @return the byte read, or -1 if the end of the stream is reached. | |
| 56 | + * @exception IOException if an I/O error has occurred | |
| 57 | + */ | |
| 58 | + public int read() throws IOException { | |
| 59 | + int b = in.read(); | |
| 60 | + if (b != -1) { | |
| 61 | + cksum.update(b); | |
| 62 | + } | |
| 63 | + return b; | |
| 64 | + } | |
| 65 | + | |
| 66 | + /** | |
| 67 | + * Reads into an array of bytes. If <code>len</code> is not zero, the method | |
| 68 | + * blocks until some input is available; otherwise, no | |
| 69 | + * bytes are read and <code>0</code> is returned. | |
| 70 | + * @param buf the buffer into which the data is read | |
| 71 | + * @param off the start offset in the destination array <code>b</code> | |
| 72 | + * @param len the maximum number of bytes read | |
| 73 | + * @return the actual number of bytes read, or -1 if the end | |
| 74 | + * of the stream is reached. | |
| 75 | + * @exception NullPointerException If <code>buf</code> is <code>null</code>. | |
| 76 | + * @exception IndexOutOfBoundsException If <code>off</code> is negative, | |
| 77 | + * <code>len</code> is negative, or <code>len</code> is greater than | |
| 78 | + * <code>buf.length - off</code> | |
| 79 | + * @exception IOException if an I/O error has occurred | |
| 80 | + */ | |
| 81 | + public int read(byte[] buf, int off, int len) throws IOException { | |
| 82 | + len = in.read(buf, off, len); | |
| 83 | + if (len != -1) { | |
| 84 | + cksum.update(buf, off, len); | |
| 85 | + } | |
| 86 | + return len; | |
| 87 | + } | |
| 88 | + | |
| 89 | + /** | |
| 90 | + * Skips specified number of bytes of input. | |
| 91 | + * @param n the number of bytes to skip | |
| 92 | + * @return the actual number of bytes skipped | |
| 93 | + * @exception IOException if an I/O error has occurred | |
| 94 | + */ | |
| 95 | + public long skip(long n) throws IOException { | |
| 96 | + byte[] buf = new byte[512]; | |
| 97 | + long total = 0; | |
| 98 | + while (total < n) { | |
| 99 | + long len = n - total; | |
| 100 | + len = read(buf, 0, len < buf.length ? (int)len : buf.length); | |
| 101 | + if (len == -1) { | |
| 102 | + return total; | |
| 103 | + } | |
| 104 | + total += len; | |
| 105 | + } | |
| 106 | + return total; | |
| 107 | + } | |
| 108 | + | |
| 109 | + /** | |
| 110 | + * Returns the Checksum for this input stream. | |
| 111 | + * @return the Checksum value | |
| 112 | + */ | |
| 113 | + public Checksum getChecksum() { | |
| 114 | + return cksum; | |
| 115 | + } | |
| 116 | +} | |