01: /*
02: * ProGuard -- shrinking, optimization, obfuscation, and preverification
03: * of Java bytecode.
04: *
05: * Copyright (c) 2002-2007 Eric Lafortune (eric@graphics.cornell.edu)
06: *
07: * This program is free software; you can redistribute it and/or modify it
08: * under the terms of the GNU General Public License as published by the Free
09: * Software Foundation; either version 2 of the License, or (at your option)
10: * any later version.
11: *
12: * This program is distributed in the hope that it will be useful, but WITHOUT
13: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15: * more details.
16: *
17: * You should have received a copy of the GNU General Public License along
18: * with this program; if not, write to the Free Software Foundation, Inc.,
19: * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20: */
21: package proguard.io;
22:
23: import java.io.*;
24:
25: /**
26: * This DataEntryWriter delegates to a given DataEntryWriter, or failing that,
27: * to another given DataEntryWriter.
28: *
29: * @author Eric Lafortune
30: */
31: public class CascadingDataEntryWriter implements DataEntryWriter {
32: private DataEntryWriter dataEntryWriter1;
33: private DataEntryWriter dataEntryWriter2;
34:
35: /**
36: * Creates a new CascadingDataEntryWriter.
37: * @param dataEntryWriter1 the DataEntryWriter to which the writing will be
38: * delegated first.
39: * @param dataEntryWriter2 the DataEntryWriter to which the writing will be
40: * delegated, if the first one can't provide an
41: * output stream.
42: */
43: public CascadingDataEntryWriter(DataEntryWriter dataEntryWriter1,
44: DataEntryWriter dataEntryWriter2) {
45: this .dataEntryWriter1 = dataEntryWriter1;
46: this .dataEntryWriter2 = dataEntryWriter2;
47: }
48:
49: // Implementations for DataEntryWriter.
50:
51: public OutputStream getOutputStream(DataEntry dataEntry)
52: throws IOException {
53: return getOutputStream(dataEntry, null);
54: }
55:
56: public OutputStream getOutputStream(DataEntry dataEntry,
57: Finisher finisher) throws IOException {
58: // Try to get an output stream from the first data entry writer.
59: OutputStream outputStream = dataEntryWriter1.getOutputStream(
60: dataEntry, finisher);
61:
62: // Return it, if it's not null. Otherwise try to get an output stream
63: // from the second data entry writer.
64: return outputStream != null ? outputStream : dataEntryWriter2
65: .getOutputStream(dataEntry, finisher);
66: }
67:
68: public void close() throws IOException {
69: dataEntryWriter1.close();
70: dataEntryWriter2.close();
71:
72: dataEntryWriter1 = null;
73: dataEntryWriter2 = null;
74: }
75: }
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