01: /* ====================================================================
02: Licensed to the Apache Software Foundation (ASF) under one or more
03: contributor license agreements. See the NOTICE file distributed with
04: this work for additional information regarding copyright ownership.
05: The ASF licenses this file to You under the Apache License, Version 2.0
06: (the "License"); you may not use this file except in compliance with
07: the License. You may obtain a copy of the License at
08:
09: http://www.apache.org/licenses/LICENSE-2.0
10:
11: Unless required by applicable law or agreed to in writing, software
12: distributed under the License is distributed on an "AS IS" BASIS,
13: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14: See the License for the specific language governing permissions and
15: limitations under the License.
16: ==================================================================== */
17:
18: package org.apache.poi.poifs.storage;
19:
20: import org.apache.poi.poifs.common.POIFSConstants;
21: import org.apache.poi.util.IOUtils;
22:
23: import java.io.*;
24:
25: /**
26: * A big block created from an InputStream, holding the raw data
27: *
28: * @author Marc Johnson (mjohnson at apache dot org
29: */
30:
31: public class RawDataBlock implements ListManagedBlock {
32: private byte[] _data;
33: private boolean _eof;
34:
35: /**
36: * Constructor RawDataBlock
37: *
38: * @param stream the InputStream from which the data will be read
39: *
40: * @exception IOException on I/O errors, and if an insufficient
41: * amount of data is read
42: */
43:
44: public RawDataBlock(final InputStream stream) throws IOException {
45: _data = new byte[POIFSConstants.BIG_BLOCK_SIZE];
46: int count = IOUtils.readFully(stream, _data);
47:
48: if (count == -1) {
49: _eof = true;
50: } else if (count != POIFSConstants.BIG_BLOCK_SIZE) {
51: if (count == -1)
52: //Cant have -1 bytes read in the error message!
53: count = 0;
54:
55: String type = " byte" + ((count == 1) ? ("") : ("s"));
56:
57: throw new IOException("Unable to read entire block; "
58: + count + type + " read; expected "
59: + POIFSConstants.BIG_BLOCK_SIZE + " bytes");
60: } else {
61: _eof = false;
62: }
63: }
64:
65: /**
66: * When we read the data, did we hit end of file?
67: *
68: * @return true if no data was read because we were at the end of
69: * the file, else false
70: *
71: * @exception IOException
72: */
73:
74: public boolean eof() throws IOException {
75: return _eof;
76: }
77:
78: /* ********** START implementation of ListManagedBlock ********** */
79:
80: /**
81: * Get the data from the block
82: *
83: * @return the block's data as a byte array
84: *
85: * @exception IOException if there is no data
86: */
87:
88: public byte[] getData() throws IOException {
89: if (eof()) {
90: throw new IOException("Cannot return empty data");
91: }
92: return _data;
93: }
94:
95: /* ********** END implementation of ListManagedBlock ********** */
96: } // end public class RawDataBlock
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