1
2 /* ====================================================================
3 Licensed to the Apache Software Foundation (ASF) under one or more
4 contributor license agreements. See the NOTICE file distributed with
5 this work for additional information regarding copyright ownership.
6 The ASF licenses this file to You under the Apache License, Version 2.0
7 (the "License"); you may not use this file except in compliance with
8 the License. You may obtain a copy of the License at
9
10 http://www.apache.org/licenses/LICENSE-2.0
11
12 Unless required by applicable law or agreed to in writing, software
13 distributed under the License is distributed on an "AS IS" BASIS,
14 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 See the License for the specific language governing permissions and
16 limitations under the License.
17 ==================================================================== */
18
19 package org.apache.poi.hssf.eventusermodel;
20
21 import java.io.InputStream;
22 import java.io.IOException;
23
24 import org.apache.poi.hssf.eventusermodel.HSSFUserException;
25 import org.apache.poi.hssf.record;
26 import org.apache.poi.poifs.filesystem.POIFSFileSystem;
27
28 /**
29 * Low level event based HSSF reader. Pass either a DocumentInputStream to
30 * process events along with a request object or pass a POIFS POIFSFileSystem to
31 * processWorkbookEvents along with a request.
32 *
33 * This will cause your file to be processed a record at a time. Each record with
34 * a static id matching one that you have registed in your HSSFRequest will be passed
35 * to your associated HSSFListener.
36 *
37 * @see org.apache.poi.hssf.dev.EFHSSF
38 *
39 * @author Andrew C. Oliver (acoliver at apache dot org)
40 * @author Carey Sublette (careysub@earthling.net)
41 */
42
43 public class HSSFEventFactory
44 {
45 /** Creates a new instance of HSSFEventFactory */
46
47 public HSSFEventFactory()
48 {
49 }
50
51 /**
52 * Processes a file into essentially record events.
53 *
54 * @param req an Instance of HSSFRequest which has your registered listeners
55 * @param fs a POIFS filesystem containing your workbook
56 */
57
58 public void processWorkbookEvents(HSSFRequest req, POIFSFileSystem fs)
59 throws IOException
60 {
61 InputStream in = fs.createDocumentInputStream("Workbook");
62
63 processEvents(req, in);
64 }
65
66 /**
67 * Processes a file into essentially record events.
68 *
69 * @param req an Instance of HSSFRequest which has your registered listeners
70 * @param fs a POIFS filesystem containing your workbook
71 * @return numeric user-specified result code.
72 */
73
74 public short abortableProcessWorkbookEvents(HSSFRequest req, POIFSFileSystem fs)
75 throws IOException, HSSFUserException
76 {
77 InputStream in = fs.createDocumentInputStream("Workbook");
78 return abortableProcessEvents(req, in);
79 }
80
81 /**
82 * Processes a DocumentInputStream into essentially Record events.
83 *
84 * If an <code>AbortableHSSFListener</code> causes a halt to processing during this call
85 * the method will return just as with <code>abortableProcessEvents</code>, but no
86 * user code or <code>HSSFUserException</code> will be passed back.
87 *
88 * @see org.apache.poi.poifs.filesystem.POIFSFileSystem#createDocumentInputStream(String)
89 * @param req an Instance of HSSFRequest which has your registered listeners
90 * @param in a DocumentInputStream obtained from POIFS's POIFSFileSystem object
91 */
92
93 public void processEvents(HSSFRequest req, InputStream in)
94 throws IOException
95 {
96 try
97 {
98 genericProcessEvents(req, new RecordInputStream(in));
99 }
100 catch (HSSFUserException hue)
101 {/*If an HSSFUserException user exception is thrown, ignore it.*/ }
102 }
103
104
105 /**
106 * Processes a DocumentInputStream into essentially Record events.
107 *
108 * @see org.apache.poi.poifs.filesystem.POIFSFileSystem#createDocumentInputStream(String)
109 * @param req an Instance of HSSFRequest which has your registered listeners
110 * @param in a DocumentInputStream obtained from POIFS's POIFSFileSystem object
111 * @return numeric user-specified result code.
112 */
113
114 public short abortableProcessEvents(HSSFRequest req, InputStream in)
115 throws IOException, HSSFUserException
116 {
117 return genericProcessEvents(req, new RecordInputStream(in));
118 }
119
120 /**
121 * Processes a DocumentInputStream into essentially Record events.
122 *
123 * @see org.apache.poi.poifs.filesystem.POIFSFileSystem#createDocumentInputStream(String)
124 * @param req an Instance of HSSFRequest which has your registered listeners
125 * @param in a DocumentInputStream obtained from POIFS's POIFSFileSystem object
126 * @return numeric user-specified result code.
127 */
128
129 protected short genericProcessEvents(HSSFRequest req, RecordInputStream in)
130 throws IOException, HSSFUserException
131 {
132 boolean going = true;
133 short userCode = 0;
134 Record r = null;
135
136 // Create a new RecordStream and use that
137 HSSFRecordStream recordStream = new HSSFRecordStream(in);
138
139 // Process each record as they come in
140 while(going) {
141 r = recordStream.nextRecord();
142 if(r != null) {
143 userCode = req.processRecord(r);
144 if (userCode != 0) break;
145 } else {
146 going = false;
147 }
148 }
149
150 // All done, return our last code
151 return userCode;
152 }
153 }
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