/*
* Copyright (c) OSGi Alliance (2005, 2008). All Rights Reserved.
*
* Licensed 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.osgi.service.condpermadmin;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Hashtable;
import org.osgi.framework.Bundle;
import org.osgi.framework.Filter;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.InvalidSyntaxException;
/**
* Condition to test if the location of a bundle matches or does not match a
* pattern. Since the bundle's location cannot be changed, this condition is
* immutable.
*
* <p>
* Pattern matching is done according to the filter string matching rules.
*
* @ThreadSafe
* @version $Revision: 5901 $
*/
public class BundleLocationCondition {
private static final String CONDITION_TYPE = "org.osgi.service.condpermadmin.BundleLocationCondition";
/**
* Constructs a condition that tries to match the passed Bundle's location
* to the location pattern.
*
* @param bundle The Bundle being evaluated.
* @param info The ConditionInfo from which to construct the condition. The
* ConditionInfo must specify one or two arguments. The first
* argument of the ConditionInfo specifies the location pattern
* against which to match the bundle location. Matching is done
* according to the filter string matching rules. Any '*' characters
* in the first argument are used as wildcards when matching bundle
* locations unless they are escaped with a '\' character. The
* Condition is satisfied if the bundle location matches the pattern.
* The second argument of the ConditionInfo is optional. If a second
* argument is present and equal to "!", then the satisfaction of the
* Condition is negated. That is, the Condition is satisfied if the
* bundle location does NOT match the pattern. If the second argument
* is present but does not equal "!", then the second argument is
* ignored.
* @return Condition object for the requested condition.
*/
static public Condition getCondition(final Bundle bundle,
final ConditionInfo info) {
if (!CONDITION_TYPE.equals(info.getType()))
throw new IllegalArgumentException(
"ConditionInfo must be of type \"" + CONDITION_TYPE + "\"");
String[] args = info.getArgs();
if (args.length != 1 && args.length != 2)
throw new IllegalArgumentException("Illegal number of args: " + args.length);
String bundleLocation = (String) AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
return bundle.getLocation();
}
});
Filter filter = null;
try {
filter = FrameworkUtil.createFilter("(location="
+ escapeLocation(args[0]) + ")");
}
catch (InvalidSyntaxException e) {
// this should never happen, but just in case
throw new RuntimeException("Invalid filter: " + e.getFilter(), e);
}
Hashtable matchProps = new Hashtable(2);
matchProps.put("location", bundleLocation);
boolean negate = (args.length == 2) ? "!".equals(args[1]) : false;
return (negate ^ filter.match(matchProps)) ? Condition.TRUE
: Condition.FALSE;
}
private BundleLocationCondition() {
// private constructor to prevent objects of this type
}
/**
* Escape the value string such that '(', ')' and '\' are escaped. The '\'
* char is only escaped if it is not followed by a '*'.
*
* @param value unescaped value string.
* @return escaped value string.
*/
private static String escapeLocation(final String value) {
boolean escaped = false;
int inlen = value.length();
int outlen = inlen << 1; /* inlen * 2 */
char[] output = new char[outlen];
value.getChars(0, inlen, output, inlen);
int cursor = 0;
for (int i = inlen; i < outlen; i++) {
char c = output[i];
switch (c) {
case '\\' :
if (i + 1 < outlen && output[i + 1] == '*')
break;
case '(' :
case ')' :
output[cursor] = '\\';
cursor++;
escaped = true;
break;
}
output[cursor] = c;
cursor++;
}
return escaped ? new String(output, 0, cursor) : value;
}
}