source: release-kits/lirk3/bin/ant-installer/src/org/tp23/antinstaller/runtime/exe/FilterFactory.java@ 14982

/* 
 * Copyright 2005 Paul Hinds
 *
 * 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.tp23.antinstaller.runtime.exe;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.tp23.antinstaller.InstallException;
import org.tp23.antinstaller.InstallerContext;


/**
 * Loads FilterChains from resource files on the classpath with lists of class
 * names listed in order.  In the files lines starting with # and blank
 * lines are ignored
 * @author Paul Hinds
 * @version $Id: FilterFactory.java,v 1.4 2007/01/04 22:57:18 teknopaul Exp $
 */
public class FilterFactory {
    
    public static final String FILTER_RESOURCE = "/antinstall-config.fconfig";

    private FilterFactory() {
    }

    public static FilterChain factory(String configResource) throws InstallException{
        try {
            InputStream is = FilterFactory.class.getResourceAsStream(configResource);
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            String filterClass = null;
            final List filterChain = new ArrayList();
            while((filterClass = br.readLine())!=null){
                if(filterClass.startsWith("#"))continue;
                filterClass = filterClass.trim();
                if(filterClass.equals("")){
                    continue;
                }
                filterChain.add( Class.forName(filterClass).newInstance() );
            }
            br.close();
            return new DynamicFilterChain(configResource, filterChain);
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        throw new InstallException("Can not create FilterChain");
    }
        
    static class DynamicFilterChain implements FilterChain{
        
        private ExecuteFilter[] filters;
        private String configResource;
        
        private DynamicFilterChain(String configResource, List filterChain){
            this.configResource = configResource;
            filters = new ExecuteFilter[filterChain.size()];
            filterChain.toArray(filters);
        }
        public void init(InstallerContext ctx){
            ctx.setConfigResource(configResource);
        }
        public ExecuteFilter[] getFilters(){
            return filters;
        }
    };
}