/*
* Copyright 2001-2004 Fraunhofer Gesellschaft, Munich, Germany, for its
* Fraunhofer Institute Computer Architecture and Software Technology
* (FIRST), Berlin, Germany
*
* 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 gabriel.components.io;
import gabriel.Permission;
import gabriel.Principal;
import gabriel.acl.Acl;
import gabriel.acl.AclEntry;
import gabriel.components.AclStore;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.StringTokenizer;
/**
* Stores Acl in files with <name>.acl
*
* @author stephan
* @version $id$
*/
public class FileAclStore implements AclStore {
// throws AclNotFoundException
public Acl getAcl(Principal owner, String name) {
Reader input = null;
try {
input = new InputStreamReader(FileAclStore.class.getResourceAsStream("/" + name + ".acl"));
} catch (Exception e) {
e.printStackTrace();
}
return parse(owner, name, input);
}
/**
* Parse an Acl description. Needs to throw an exception.
* <code>
* Principal { Permission Permission }
* Principal { Permission }
* </code>
*
* @param owner Principal who owns the Acl
* @param name Name of the Acl
* @param in Description source
* @return Parsed Acl
*/
public Acl parse(Principal owner, String name, Reader in) {
BufferedReader reader = new BufferedReader(in);
StringBuffer buffer = new StringBuffer();
try {
String line = "";
while (null != (line = reader.readLine())) {
buffer.append(line);
buffer.append("\n");
}
} catch (IOException e) {
e.printStackTrace();
}
String input = buffer.toString();
return parse(owner, name, input);
}
private Acl parse(Principal owner, String name, String input) {
boolean negative = false;
Principal principal = null;
List permissions = new ArrayList();
Acl acl = new Acl(owner, name);
int PERMISSIONS = 1;
int PRINCIPAL = 2;
int state = PRINCIPAL;
for (StringTokenizer stringTokenizer = new StringTokenizer(input, " \n{}", true);
stringTokenizer.hasMoreTokens();) {
String t = stringTokenizer.nextToken();
if (" ".equals(t) || "\n".equals(t)) {
// do nothing
} else if ("{".equals(t)) {
state = PERMISSIONS;
} else if ("}".equals(t)) {
state = PRINCIPAL;
AclEntry entry = new AclEntry(principal);
Iterator iterator = permissions.iterator();
while (iterator.hasNext()) {
Permission permission = (Permission) iterator.next();
entry.addPermission(permission);
}
if (negative) {
entry.setNegativePermissions();
negative = false;
}
acl.addEntry(owner, entry);
permissions = new ArrayList();
principal = null;
} else if (state == PRINCIPAL) {
if (t.startsWith("-")) {
negative = true;
t = t.substring(1);
}
// handle "- principal" and "-principal"
if (!"".equals(t)) {
principal = new Principal(t);
}
} else if (state == PERMISSIONS) {
permissions.add(new Permission(t));
}
}
return acl;
}
}