File: JasperLoader.java

package info (click to toggle)
tomcat7 7.0.56-3%2Bdeb8u11
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 35,688 kB
  • ctags: 41,823
  • sloc: java: 249,464; xml: 51,553; jsp: 3,037; sh: 1,361; perl: 269; makefile: 195
file content (172 lines) | stat: -rw-r--r-- 6,584 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jasper.servlet;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.CodeSource;
import java.security.PermissionCollection;

import org.apache.jasper.Constants;

/**
 * Class loader for loading servlet class files (corresponding to JSP files) 
 * and tag handler class files (corresponding to tag files).
 *
 * @author Anil K. Vijendran
 * @author Harish Prabandham
 * @author Jean-Francois Arcand
 */
public class JasperLoader extends URLClassLoader {

    private PermissionCollection permissionCollection;
    private ClassLoader parent;
    private SecurityManager securityManager;

    public JasperLoader(URL[] urls, ClassLoader parent,
                        PermissionCollection permissionCollection) {
        super(urls, parent);
        this.permissionCollection = permissionCollection;
        this.parent = parent;
        this.securityManager = System.getSecurityManager();
    }

    /**
     * Load the class with the specified name.  This method searches for
     * classes in the same manner as <code>loadClass(String, boolean)</code>
     * with <code>false</code> as the second argument.
     *
     * @param name Name of the class to be loaded
     *
     * @exception ClassNotFoundException if the class was not found
     */
    @Override
    public Class<?> loadClass(String name) throws ClassNotFoundException {

        return (loadClass(name, false));
    }

    /**
     * Load the class with the specified name, searching using the following
     * algorithm until it finds and returns the class.  If the class cannot
     * be found, returns <code>ClassNotFoundException</code>.
     * <ul>
     * <li>Call <code>findLoadedClass(String)</code> to check if the
     *     class has already been loaded.  If it has, the same
     *     <code>Class</code> object is returned.</li>
     * <li>If the <code>delegate</code> property is set to <code>true</code>,
     *     call the <code>loadClass()</code> method of the parent class
     *     loader, if any.</li>            
     * <li>Call <code>findClass()</code> to find this class in our locally
     *     defined repositories.</li>      
     * <li>Call the <code>loadClass()</code> method of our parent
     *     class loader, if any.</li>      
     * </ul>
     * If the class was found using the above steps, and the
     * <code>resolve</code> flag is <code>true</code>, this method will then
     * call <code>resolveClass(Class)</code> on the resulting Class object.
     *                                     
     * @param name Name of the class to be loaded
     * @param resolve If <code>true</code> then resolve the class
     *                                     
     * @exception ClassNotFoundException if the class was not found
     */                                    
    @Override
    public synchronized Class<?> loadClass(final String name, boolean resolve)
        throws ClassNotFoundException {

        Class<?> clazz = null;                
                                           
        // (0) Check our previously loaded class cache
        clazz = findLoadedClass(name);     
        if (clazz != null) {               
            if (resolve)                   
                resolveClass(clazz);       
            return (clazz);        
        }                          
                          
        // (.5) Permission to access this class when using a SecurityManager
        if (securityManager != null) {     
            int dot = name.lastIndexOf('.');
            if (dot >= 0) {                
                try {        
                    // Do not call the security manager since by default, we grant that package.
                    if (!"org.apache.jasper.runtime".equalsIgnoreCase(name.substring(0,dot))){
                        securityManager.checkPackageAccess(name.substring(0,dot));
                    }
                } catch (SecurityException se) {
                    String error = "Security Violation, attempt to use " +
                        "Restricted Class: " + name;
                    se.printStackTrace();
                    throw new ClassNotFoundException(error);
                }                          
            }                              
        }

        if( !name.startsWith(Constants.JSP_PACKAGE_NAME + '.') ) {
            // Class is not in org.apache.jsp, therefore, have our
            // parent load it
            clazz = parent.loadClass(name);            
            if( resolve )
                resolveClass(clazz);
            return clazz;
        }

        return findClass(name);
    }

    
    /**
     * Delegate to parent
     * 
     * @see java.lang.ClassLoader#getResourceAsStream(java.lang.String)
     */
    @Override
    public InputStream getResourceAsStream(String name) {
        InputStream is = parent.getResourceAsStream(name);
        if (is == null) {
            URL url = findResource(name);
            if (url != null) {
                try {
                    is = url.openStream();
                } catch (IOException e) {
                    // Ignore
                }
            }
        }
        return is;
    }
    
    
    /**
     * Get the Permissions for a CodeSource.
     *
     * Since this ClassLoader is only used for a JSP page in
     * a web application context, we just return our preset
     * PermissionCollection for the web app context.
     *
     * @param codeSource Code source where the code was loaded from
     * @return PermissionCollection for CodeSource
     */
    @Override
    public final PermissionCollection getPermissions(CodeSource codeSource) {
        return permissionCollection;
    }
}