| /* |
| * Copyright 2000,2004 The Apache Software Foundation. |
| * |
| * 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.apache.webapp.balancer; |
| |
| import org.apache.tomcat.util.digester.Digester; |
| |
| import java.io.InputStream; |
| |
| |
| /** |
| * The rules parser uses Digester |
| * to parse the rules definition |
| * file and return a RuleChain object. |
| * |
| * @author Yoav Shapira |
| */ |
| public class RulesParser { |
| /** |
| * The resulting rule chain. |
| */ |
| private RuleChain result; |
| |
| /** |
| * Constructor. |
| * |
| * @param input To read the configuration |
| */ |
| public RulesParser(InputStream input) { |
| try { |
| Digester digester = createDigester(); |
| result = (RuleChain) digester.parse(input); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * Returns the parsed rule chain. |
| * |
| * @return The resulting RuleChain |
| */ |
| public RuleChain getResult() { |
| return result; |
| } |
| |
| /** |
| * Creates the digester instance. |
| * |
| * @return Digester |
| */ |
| protected Digester createDigester() { |
| Digester digester = new Digester(); |
| digester.setUseContextClassLoader(true); |
| |
| String rules = "rules"; |
| String rule = "/rule"; |
| |
| // Construct rule chain |
| digester.addObjectCreate(rules, RuleChain.class); |
| |
| // Construct rule |
| digester.addObjectCreate(rules + rule, null, "className"); |
| |
| // Set rule properties |
| digester.addSetProperties(rules + rule); |
| |
| // Add rule to chain |
| digester.addSetNext(rules + rule, "addRule", "org.apache.webapp.balancer.Rule"); |
| |
| return digester; |
| } |
| } |
| |
| |
| // End of class: RulesParser.java |