001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.xbean.naming.context; 018 019 import javax.naming.Name; 020 import javax.naming.NamingException; 021 import java.util.List; 022 import java.util.Iterator; 023 import java.util.Collections; 024 import java.util.ArrayList; 025 026 /** 027 * @version $Rev$ $Date$ 028 */ 029 public class ContextAccessControlList implements ContextAccess { 030 private final boolean defaultAllow; 031 private final List allow; 032 private final List deny; 033 034 public ContextAccessControlList(boolean defaultAllow, List allow, List deny) { 035 this.defaultAllow = defaultAllow; 036 this.allow = toACL(allow); 037 this.deny = toACL(deny); 038 } 039 040 private List toACL(List input) { 041 if (input == null) return Collections.EMPTY_LIST; 042 043 ArrayList list = new ArrayList(input.size()); 044 for (Iterator iterator = input.iterator(); iterator.hasNext();) { 045 Object value = iterator.next(); 046 if (value instanceof Name) { 047 list.add(value); 048 } else if (value instanceof String) { 049 String string = (String) value; 050 Name name = null; 051 try { 052 name = ContextUtil.NAME_PARSER.parse(string); 053 } catch (NamingException e) { 054 throw new IllegalArgumentException("error while parsing name: " + value); 055 } 056 list.add(name); 057 } else { 058 throw new IllegalArgumentException("name is not an instance of Name or String: " + value); 059 } 060 } 061 return Collections.unmodifiableList(list); 062 } 063 064 public boolean isModifiable(Name name) { 065 if (name == null) throw new NullPointerException("name is null"); 066 if (defaultAllow) { 067 // allow by default, so allow if it wasn't explicitly denied or was explicitly allowed 068 return !isDenied(name) || isAllowed(name); 069 } else { 070 // deny by default, so allow if it was explicitly allowed or wasn't explicitly denied 071 return isAllowed(name) && !isDenied(name); 072 } 073 } 074 075 protected boolean isAllowed(Name name) { 076 if (name == null) throw new NullPointerException("name is null"); 077 for (Iterator iterator = allow.iterator(); iterator.hasNext();) { 078 Name prefix = (Name) iterator.next(); 079 if (name.startsWith(prefix)) { 080 return true; 081 } 082 } 083 084 return false; 085 } 086 087 protected boolean isDenied(Name name) { 088 if (name == null) throw new NullPointerException("name is null"); 089 for (Iterator iterator = deny.iterator(); iterator.hasNext();) { 090 Name prefix = (Name) iterator.next(); 091 if (name.startsWith(prefix)) { 092 return true; 093 } 094 } 095 096 return false; 097 } 098 }