1/*
2 [The "BSD license"]
3 Copyright (c) 2005-2009 Terence Parr
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions
8 are met:
9 1. Redistributions of source code must retain the above copyright
10     notice, this list of conditions and the following disclaimer.
11 2. Redistributions in binary form must reproduce the above copyright
12     notice, this list of conditions and the following disclaimer in the
13     documentation and/or other materials provided with the distribution.
14 3. The name of the author may not be used to endorse or promote products
15     derived from this software without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28package org.antlr.runtime;
29
30import java.io.*;
31
32/** This is a char buffer stream that is loaded from a file
33 *  all at once when you construct the object.  This looks very
34 *  much like an ANTLReader or ANTLRInputStream, but it's a special case
35 *  since we know the exact size of the object to load.  We can avoid lots
36 *  of data copying.
37 */
38public class ANTLRFileStream extends ANTLRStringStream {
39	protected String fileName;
40
41	public ANTLRFileStream(String fileName) throws IOException {
42		this(fileName, null);
43	}
44
45	public ANTLRFileStream(String fileName, String encoding) throws IOException {
46		this.fileName = fileName;
47		load(fileName, encoding);
48	}
49
50	public void load(String fileName, String encoding)
51		throws IOException
52	{
53		if ( fileName==null ) {
54			return;
55		}
56		File f = new File(fileName);
57		int size = (int)f.length();
58		InputStreamReader isr;
59		FileInputStream fis = new FileInputStream(fileName);
60		if ( encoding!=null ) {
61			isr = new InputStreamReader(fis, encoding);
62		}
63		else {
64			isr = new InputStreamReader(fis);
65		}
66		try {
67			data = new char[size];
68			super.n = isr.read(data);
69		}
70		finally {
71			isr.close();
72		}
73	}
74
75	public String getSourceName() {
76		return fileName;
77	}
78}
79