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Diffstat (limited to 'libjava/java/security/BasicPermission.java')
| -rw-r--r-- | libjava/java/security/BasicPermission.java | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/libjava/java/security/BasicPermission.java b/libjava/java/security/BasicPermission.java new file mode 100644 index 0000000..f2e70ed --- /dev/null +++ b/libjava/java/security/BasicPermission.java @@ -0,0 +1,271 @@ +/* BasicPermission.java -- Implements a simple named permission. + Copyright (C) 1998, 1999 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +As a special exception, if you link this library with other files to +produce an executable, this library does not by itself cause the +resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why the +executable file might be covered by the GNU General Public License. */ + + +package java.security; + +import java.io.Serializable; +import java.util.Hashtable; +import java.util.Enumeration; + +/** + * This class implements a simple model for named permissions without an + * associated action list. That is, either the named permission is granted + * or it is not. + * <p> + * It also supports trailing wildcards to allow the + * easy granting of permissions in a hierarchical fashion. (For example, + * the name "org.gnu.*" might grant all permissions under the "org.gnu" + * permissions hierarchy). The only valid wildcard character is a '*' + * which matches anything. It must be the rightmost element in the + * permission name and must follow a '.' or else the Permission name must + * consist of only a '*'. Any other occurrence of a '*' is not valid. + * <p> + * This class ignores the action list. Subclasses can choose to implement + * actions on top of this class if desired. + * + * @version 0.1 + * + * @author Aaron M. Renn (arenn@urbanophile.com) + */ +public abstract class BasicPermission extends Permission implements Serializable +{ + + /*************************************************************************/ + + /* + * Constructors + */ + + /** + * This method initializes a new instance of <code>BasicPermission</code> + * with the specified name. If the name contains an illegal wildcard + * character, an exception is thrown. + * + * @param name The name of this permission. + * + * @exception IllegalArgumentException If the name contains an invalid wildcard character + * @exception NullPointerException If the name is null + */ + public + BasicPermission(String name) throws IllegalArgumentException, NullPointerException + { + super(name); + + if (name.indexOf("*") != -1) + { + if (!name.endsWith(".*") && !name.equals("*")) + throw new IllegalArgumentException("Bad wildcard: " + name); + + if (name.indexOf("*") != name.lastIndexOf("*")) + throw new IllegalArgumentException("Bad wildcard: " + name); + } + } + + /*************************************************************************/ + + /** + * This method initializes a new instance of <code>BasicPermission</code> + * with the specified name. If the name contains an illegal wildcard + * character, an exception is thrown. The action list passed to this + * form of the constructor is ignored. + * + * @param name The name of this permission. + * @param actions The list of actions for this permission - ignored in this class. + * + * @exception IllegalArgumentException If the name contains an invalid wildcard character + * @exception NullPointerException If the name is null + */ + public + BasicPermission(String name, String actions) throws IllegalArgumentException, NullPointerException + { + // ignore actions + this(name); + } + + /*************************************************************************/ + + /** + * This method tests to see if the specified permission is implied by + * this permission. This will be true if the following conditions are met: + * <p> + * <ul> + * <li>The specified object is an instance of <code>BasicPermission</code>, + * or a subclass. + * <li>The name of the specified permission is identical to this permission's + * name or the name of the specified permission satisfies a wildcard match + * on this permission. + * </ul> + * + * @param perm The <code>Permission</code> object to test against. + * + * @return <code>true</code> if the specified permission is implied by this one or <code>false</code> otherwise. + */ + public boolean + implies(Permission perm) + { + if (!(perm instanceof BasicPermission)) + return false; + + String otherName = perm.getName(); + String name = getName(); + + if (name.equals(otherName)) + return true; + + int last = name.length() - 1; + if (name.charAt(last) == '*' + && otherName.startsWith(name.substring(0, last))) + return true; + + return false; + } + + /*************************************************************************/ + + /** + * This method tests to see if this object is equal to the specified + * <code>Object</code>. This will be true if and only if the specified + * object meets the following conditions: + * <p> + * <ul> + * <li>It is an instance of <code>BasicPermission</code>, or a subclass. + * <li>It has the same name as this permission. + * </ul> + * + * @param obj The <code>Object</code> to test for equality against this object + * + * @return <code>true</code> if the specified <code>Object</code> is equal to this object or <code>false</code> otherwise. + */ + public boolean + equals(Object obj) + { + if (!(obj instanceof BasicPermission)) + return(false); + + if (!getName().equals(((BasicPermission)obj).getName())) + return(false); + + return(true); + } + + /*************************************************************************/ + + /** + * This method returns a hash code for this permission object. The hash + * code returned is the value returned by calling the <code>hashCode</code> + * method on the <code>String</code> that is the name of this permission. + * + * @return A hash value for this object + */ + public int + hashCode() + { + return(getName().hashCode()); + } + + /*************************************************************************/ + + /** + * This method returns a list of the actions associated with this + * permission. This method always returns the empty string ("") since + * this class ignores actions. + * + * @return The action list. + */ + public String + getActions() + { + return(""); + } + + /*************************************************************************/ + + /** + * This method returns an instance of <code>PermissionCollection</code> + * suitable for storing <code>BasicPermission</code> objects. This returns + * be a sub class of <code>PermissionCollection</code> + * that allows for an efficient and consistent implementation of + * the <code>implies</code> method. The collection doesn't handle subclasses + * of BasicPermission correctly; they must override this method. + * + * @return A new empty <code>PermissionCollection</code> object. + */ + public PermissionCollection + newPermissionCollection() + { + return new PermissionCollection() + { + Hashtable permissions = new Hashtable(); + boolean allAllowed = false; + + public void add(Permission permission) + { + if (isReadOnly()) + throw new IllegalStateException("readonly"); + + BasicPermission bp = (BasicPermission) permission; + String name = bp.getName(); + if (name.equals("*")) + allAllowed = true; + permissions.put(name, bp); + } + + public boolean implies(Permission permission) + { + if (!(permission instanceof BasicPermission)) + return false; + + if (allAllowed) + return true; + + BasicPermission toImply = (BasicPermission) permission; + String name = toImply.getName(); + if (name.equals("*")) + return false; + + int prefixLength = name.length(); + if (name.endsWith("*")) + prefixLength -= 2; + + while (true) { + if (permissions.get(name) != null) + return true; + + prefixLength = name.lastIndexOf('.', prefixLength); + if (prefixLength < 0) + return false; + name = name.substring(0, prefixLength + 1) + '*'; + } + } + + public Enumeration elements() + { + return permissions.elements(); + } + }; + } +} // class BasicPermission |