| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.services.io.NewByteArrayInputStream |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.services.io; |
| 22 | |
| 23 | import java.io.InputStream; |
| 24 | import java.io.IOException; |
| 25 | |
| 26 | /** |
| 27 | An InputStream that is like java.io.ByteArrayInputStream but supports |
| 28 | a close() call that causes all methods to throw an IOException. |
| 29 | Java's ByteInputStream has a close() method that does not do anything. |
| 30 | */ |
| 31 | public final class NewByteArrayInputStream extends InputStream { |
| 32 | |
| 33 | private byte[] data; |
| 34 | private int offset; |
| 35 | private int length; |
| 36 | |
| 37 | public NewByteArrayInputStream(byte[] data) { |
| 38 | this(data, 0, data.length); |
| 39 | } |
| 40 | |
| 41 | public NewByteArrayInputStream(byte[] data, int offset, int length) { |
| 42 | this.data = data; |
| 43 | this.offset = offset; |
| 44 | this.length = length; |
| 45 | } |
| 46 | |
| 47 | /* |
| 48 | ** Public methods |
| 49 | */ |
| 50 | public int read() throws IOException { |
| 51 | if (data == null) |
| 52 | throw new IOException(); |
| 53 | |
| 54 | if (length == 0) |
| 55 | return -1; // end of file |
| 56 | |
| 57 | length--; |
| 58 | |
| 59 | return data[offset++] & 0xff ; |
| 60 | |
| 61 | } |
| 62 | |
| 63 | public int read(byte b[], int off, int len) throws IOException { |
| 64 | if (data == null) |
| 65 | throw new IOException(); |
| 66 | |
| 67 | if (length == 0) |
| 68 | return -1; |
| 69 | |
| 70 | if (len > length) |
| 71 | len = length; |
| 72 | |
| 73 | System.arraycopy(data, offset, b, off, len); |
| 74 | offset += len; |
| 75 | length -= len; |
| 76 | return len; |
| 77 | } |
| 78 | |
| 79 | public long skip(long count) throws IOException { |
| 80 | if (data == null) |
| 81 | throw new IOException(); |
| 82 | |
| 83 | if (length == 0) |
| 84 | return -1; |
| 85 | |
| 86 | if (count > length) |
| 87 | count = length; |
| 88 | |
| 89 | offset += (int) count; |
| 90 | length -= (int) count; |
| 91 | |
| 92 | return count; |
| 93 | |
| 94 | } |
| 95 | |
| 96 | public int available() throws IOException |
| 97 | { |
| 98 | if (data == null) |
| 99 | throw new IOException(); |
| 100 | |
| 101 | return length; |
| 102 | } |
| 103 | |
| 104 | public byte[] getData() { return data; } |
| 105 | |
| 106 | public void close() |
| 107 | { |
| 108 | data = null; |
| 109 | } |
| 110 | |
| 111 | } |