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1: /* java.lang.reflect.AccessibleObject 2: Copyright (C) 2001, 2005 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.lang.reflect; 40: 41: /** 42: * This class is the superclass of various reflection classes, and 43: * allows sufficiently trusted code to bypass normal restrictions to 44: * do necessary things like invoke private methods outside of the 45: * class during Serialization. If you don't have a good reason 46: * to mess with this, don't try. Fortunately, there are adequate 47: * security checks before you can set a reflection object as accessible. 48: * 49: * @author Tom Tromey (tromey@cygnus.com) 50: * @author Eric Blake (ebb9@email.byu.edu) 51: * @see Field 52: * @see Constructor 53: * @see Method 54: * @see ReflectPermission 55: * @since 1.2 56: * @status updated to 1.4 57: */ 58: public class AccessibleObject 59: { 60: /** 61: * True if this object is marked accessible, which means the reflected 62: * object bypasses normal security checks. 63: */ 64: // default visibility for use by inherited classes 65: boolean flag = false; 66: 67: /** 68: * Only the three reflection classes that extend this can create an 69: * accessible object. This is not serializable for security reasons. 70: */ 71: protected AccessibleObject() 72: { 73: } 74: 75: /** 76: * Return the accessibility status of this object. 77: * 78: * @return true if this object bypasses security checks 79: */ 80: public boolean isAccessible() 81: { 82: return flag; 83: } 84: 85: /** 86: * Convenience method to set the flag on a number of objects with a single 87: * security check. If a security manager exists, it is checked for 88: * <code>ReflectPermission("suppressAccessChecks")</code>.<p> 89: * 90: * It is forbidden to set the accessibility flag to true on any constructor 91: * for java.lang.Class. This will result in a SecurityException. If the 92: * SecurityException is thrown for any of the passed AccessibleObjects, 93: * the accessibility flag will be set on AccessibleObjects in the array prior 94: * to the one which resulted in the exception. 95: * 96: * @param array the array of accessible objects 97: * @param flag the desired state of accessibility, true to bypass security 98: * @throws NullPointerException if array is null 99: * @throws SecurityException if the request is denied 100: * @see SecurityManager#checkPermission(java.security.Permission) 101: * @see RuntimePermission 102: */ 103: public static void setAccessible(AccessibleObject[] array, boolean flag) 104: { 105: checkPermission(); 106: for (int i = 0; i < array.length; i++) 107: array[i].secureSetAccessible(flag); 108: } 109: 110: /** 111: * Sets the accessibility flag for this reflection object. If a security 112: * manager exists, it is checked for 113: * <code>ReflectPermission("suppressAccessChecks")</code>.<p> 114: * 115: * It is forbidden to set the accessibility flag to true on any constructor for 116: * java.lang.Class. This will result in a SecurityException. 117: * 118: * @param flag the desired state of accessibility, true to bypass security 119: * @throws NullPointerException if array is null 120: * @throws SecurityException if the request is denied 121: * @see SecurityManager#checkPermission(java.security.Permission) 122: * @see RuntimePermission 123: */ 124: public void setAccessible(boolean flag) 125: { 126: checkPermission(); 127: secureSetAccessible(flag); 128: } 129: 130: /** 131: * Performs the specified security check, for 132: * <code>ReflectPermission("suppressAccessChecks")</code>. 133: * 134: * @throws SecurityException if permission is denied 135: */ 136: private static void checkPermission() 137: { 138: SecurityManager sm = System.getSecurityManager(); 139: if (sm != null) 140: sm.checkPermission(new ReflectPermission("suppressAccessChecks")); 141: } 142: 143: /** 144: * Performs the actual accessibility change, this must always be invoked 145: * after calling checkPermission. 146: * 147: * @param flag the desired status 148: * @throws SecurityException if flag is true and this is a constructor 149: * for <code>java.lang.Class</code>. 150: */ 151: private void secureSetAccessible(boolean flag) 152: { 153: if (flag && 154: (this instanceof Constructor 155: && ((Constructor) this).getDeclaringClass() == Class.class)) 156: throw new SecurityException("Cannot make object accessible: " + this); 157: this.flag = flag; 158: } 159: }
GNU Classpath (0.20) |