001 /* $Id: LoaderFromStream.java 471661 2006-11-06 08:09:25Z skitching $ 002 * 003 * Licensed to the Apache Software Foundation (ASF) under one or more 004 * contributor license agreements. See the NOTICE file distributed with 005 * this work for additional information regarding copyright ownership. 006 * The ASF licenses this file to You under the Apache License, Version 2.0 007 * (the "License"); you may not use this file except in compliance with 008 * the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019 package org.apache.commons.digester.plugins.strategies; 020 021 import java.io.InputStream; 022 import java.io.ByteArrayInputStream; 023 import java.io.ByteArrayOutputStream; 024 import java.io.IOException; 025 import org.xml.sax.InputSource; 026 027 import org.apache.commons.digester.Digester; 028 import org.apache.commons.digester.plugins.RuleLoader; 029 import org.apache.commons.digester.plugins.PluginException; 030 import org.apache.commons.digester.xmlrules.FromXmlRuleSet; 031 import org.apache.commons.logging.Log; 032 033 /** 034 * A rule-finding algorithm which loads an xmlplugins-format file. 035 * <p> 036 * Note that the "include" feature of xmlrules is not supported. 037 * 038 * @since 1.6 039 */ 040 041 public class LoaderFromStream extends RuleLoader { 042 043 private byte[] input; 044 private FromXmlRuleSet ruleSet; 045 046 /** See {@link #load}. */ 047 public LoaderFromStream(InputStream s) throws Exception { 048 load(s); 049 } 050 051 /** 052 * The contents of the input stream are loaded into memory, and 053 * cached for later use. 054 * <p> 055 * The caller is responsible for closing the input stream after this 056 * method has returned. 057 */ 058 private void load(InputStream s) throws IOException { 059 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 060 byte[] buf = new byte[256]; 061 for(;;) { 062 int i = s.read(buf); 063 if (i == -1) 064 break; 065 baos.write(buf, 0, i); 066 } 067 input = baos.toByteArray(); 068 } 069 070 /** 071 * Add the rules previously loaded from the input stream into the 072 * specified digester. 073 */ 074 public void addRules(Digester d, String path) throws PluginException { 075 Log log = d.getLogger(); 076 boolean debug = log.isDebugEnabled(); 077 if (debug) { 078 log.debug( 079 "LoaderFromStream: loading rules for plugin at path [" 080 + path + "]"); 081 } 082 083 // Note that this input-source doesn't have any idea of its 084 // system id, so it has no way of resolving relative URLs 085 // such as the "include" feature of xmlrules. This is ok, 086 // because that doesn't work well with our approach of 087 // caching the input data in memory anyway. 088 089 InputSource source = new InputSource(new ByteArrayInputStream(input)); 090 FromXmlRuleSet ruleSet = new FromXmlRuleSet(source); 091 ruleSet.addRuleInstances(d, path); 092 } 093 } 094