ParserLoader.java revision 324c4644fee44b9898524c09511bd33c3f12e2df 
1/*
2 [The "BSD licence"]
3 Copyright (c) 2009 Shaoting Cai
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.gunit.swingui.runner;
29
30import java.io.*;
31import java.util.HashMap;
32
33/**
34 * Class loader for parser & lexer generated by antlr.
35 * @author Shaoting
36 */
37public class ParserLoader extends ClassLoader {
38
39    private HashMap<String, Class> classList;
40    private String grammar;
41
42    /**
43     * Create a class loader for antlr parser/lexer.
44     * @param grammarName
45     * @param classDir
46     */
47    public ParserLoader(String grammarName, String classDir) throws IOException, ClassNotFoundException {
48
49        final String lexerName = grammarName + "Lexer";
50
51        // load all the class files in the "classDir" related to the grammarName
52        File dir = new File(classDir);
53        if(dir.isDirectory()) {
54            classList = new HashMap<String, Class>();
55            grammar = grammarName;
56            File[] files = dir.listFiles(new ClassFilenameFilter(grammarName));
57            for(File f : files) {
58
59                // load class data
60                final InputStream in = new BufferedInputStream(new FileInputStream(f));
61                final byte[] classData = new byte[in.available()];
62                in.read(classData);
63                in.close();
64
65                // define class
66                final Class newClass = defineClass(null, classData, 0, classData.length);
67                assert(newClass != null);
68                resolveClass(newClass);
69
70                // save to hashtable
71                final String fileName = f.getName();
72                final String className = fileName.substring(0, fileName.lastIndexOf("."));
73                classList.put(className, newClass);
74                //System.out.println("adding: " + className);
75            }
76        } else {
77            throw new IOException(classDir + " is not a directory.");
78        }
79
80        if(classList.isEmpty() || !classList.containsKey(lexerName)) {
81            throw new ClassNotFoundException(lexerName + " not found.");
82        }
83
84    }
85
86
87
88    @Override
89    public synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
90        //System.out.print("loading: " + name);
91        if(name.startsWith(grammar)) {
92            if(classList.containsKey(name)) {
93                //System.out.println(" .... found");
94                return classList.get(name);
95            } else {
96                //System.out.println(" .... not found");
97                throw new ClassNotFoundException(name);
98            }
99
100        } else {
101            final Class c = findSystemClass(name);
102            //System.out.println(" .... system found " + c.getName());
103            return c;
104        }
105    }
106
107    /**
108     * Accepts grammarname...($...)?.class
109     */
110    protected static class ClassFilenameFilter implements FilenameFilter {
111
112        private String grammarName;
113
114        protected ClassFilenameFilter(String name) {
115            grammarName = name;
116        }
117
118        public boolean accept(File dir, String name) {
119            return name.startsWith(grammarName) && name.endsWith(".class");
120        }
121
122    }
123
124}
125