1 /*
2 * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package com.sun.naming.internal;
27
28 import java.io.InputStream;
29 import java.io.IOException;
30 import java.net.MalformedURLException;
31 import java.net.URL;
32 import java.util.Enumeration;
33 import java.util.StringTokenizer;
34 import java.util.Vector;
35
36 import javax.naming.NamingEnumeration;
37
38 /**
39 * VersionHelper was used by JNDI to accommodate differences between
40 * JDK 1.1.x and the Java 2 platform. As this is no longer necessary
41 * since JNDI's inclusion in the platform, this class currently
42 * serves as a set of utilities for performing system-level things,
43 * such as class-loading and reading system properties.
44 *
45 * @author Rosanna Lee
46 * @author Scott Seligman
47 */
48
49 public abstract class VersionHelper {
50 private static VersionHelper helper = null;
51
52 final static String[] PROPS = new String[] {
53 javax.naming.Context.INITIAL_CONTEXT_FACTORY,
54 javax.naming.Context.OBJECT_FACTORIES,
55 javax.naming.Context.URL_PKG_PREFIXES,
56 javax.naming.Context.STATE_FACTORIES,
57 javax.naming.Context.PROVIDER_URL,
58 javax.naming.Context.DNS_URL,
59 // The following shouldn't create a runtime dependence on ldap package.
60 javax.naming.ldap.LdapContext.CONTROL_FACTORIES
61 };
62
63 public final static int INITIAL_CONTEXT_FACTORY = 0;
64 public final static int OBJECT_FACTORIES = 1;
65 public final static int URL_PKG_PREFIXES = 2;
66 public final static int STATE_FACTORIES = 3;
67 public final static int PROVIDER_URL = 4;
68 public final static int DNS_URL = 5;
69 public final static int CONTROL_FACTORIES = 6;
70
71 VersionHelper() {} // Disallow anyone from creating one of these.
72
73 static {
74 helper = new VersionHelper12();
75 }
76
77 public static VersionHelper getVersionHelper() {
78 return helper;
79 }
80
81 public abstract Class loadClass(String className)
82 throws ClassNotFoundException;
83
84 abstract Class loadClass(String className, ClassLoader cl)
85 throws ClassNotFoundException;
86
87 public abstract Class loadClass(String className, String codebase)
88 throws ClassNotFoundException, MalformedURLException;
89
90 /*
91 * Returns a JNDI property from the system properties. Returns
92 * null if the property is not set, or if there is no permission
93 * to read it.
94 */
95 abstract String getJndiProperty(int i);
96
97 /*
98 * Reads each property in PROPS from the system properties, and
99 * returns their values -- in order -- in an array. For each
100 * unset property, the corresponding array element is set to null.
101 * Returns null if there is no permission to call System.getProperties().
102 */
103 abstract String[] getJndiProperties();
104
105 /*
106 * Returns the resource of a given name associated with a particular
107 * class (never null), or null if none can be found.
108 */
109 abstract InputStream getResourceAsStream(Class c, String name);
110
111 /*
112 * Returns an input stream for a file in <java.home>/lib,
113 * or null if it cannot be located or opened.
114 *
115 * @param filename The file name, sans directory.
116 */
117 abstract InputStream getJavaHomeLibStream(String filename);
118
119 /*
120 * Returns an enumeration (never null) of InputStreams of the
121 * resources of a given name associated with a particular class
122 * loader. Null represents the bootstrap class loader in some
123 * Java implementations.
124 */
125 abstract NamingEnumeration getResources(ClassLoader cl, String name)
126 throws IOException;
127
128 /*
129 * Returns the context class loader associated with the current thread.
130 * Null indicates the bootstrap class loader in some Java implementations.
131 *
132 * @throws SecurityException if the class loader is not accessible.
133 */
134 abstract ClassLoader getContextClassLoader();
135
136 static protected URL[] getUrlArray(String codebase)
137 throws MalformedURLException {
138 // Parse codebase into separate URLs
139 StringTokenizer parser = new StringTokenizer(codebase);
140 Vector vec = new Vector(10);
141 while (parser.hasMoreTokens()) {
142 vec.addElement(parser.nextToken());
143 }
144 String[] url = new String[vec.size()];
145 for (int i = 0; i < url.length; i++) {
146 url[i] = (String)vec.elementAt(i);
147 }
148
149 URL[] urlArray = new URL[url.length];
150 for (int i = 0; i < urlArray.length; i++) {
151 urlArray[i] = new URL(url[i]);
152 }
153 return urlArray;
154 }
155 }
Save This Page