001 /* $Id: LoaderFromStream.java 992107 2010-09-02 20:31:00Z simonetripodi $ 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 package org.apache.commons.digester.plugins.strategies; 019 020 import java.io.InputStream; 021 import java.io.ByteArrayInputStream; 022 import java.io.ByteArrayOutputStream; 023 import java.io.IOException; 024 import org.xml.sax.InputSource; 025 026 import org.apache.commons.digester.Digester; 027 import org.apache.commons.digester.plugins.RuleLoader; 028 import org.apache.commons.digester.plugins.PluginException; 029 import org.apache.commons.digester.xmlrules.FromXmlRuleSet; 030 import org.apache.commons.logging.Log; 031 032 /** 033 * A rule-finding algorithm which loads an xmlplugins-format file. 034 * <p> 035 * Note that the "include" feature of xmlrules is not supported. 036 * 037 * @since 1.6 038 */ 039 040 public class LoaderFromStream extends RuleLoader { 041 042 private byte[] input; 043 044 /** See {@link #load}. */ 045 public LoaderFromStream(InputStream s) throws Exception { 046 load(s); 047 } 048 049 /** 050 * The contents of the input stream are loaded into memory, and 051 * cached for later use. 052 * <p> 053 * The caller is responsible for closing the input stream after this 054 * method has returned. 055 */ 056 private void load(InputStream s) throws IOException { 057 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 058 byte[] buf = new byte[256]; 059 for(;;) { 060 int i = s.read(buf); 061 if (i == -1) 062 break; 063 baos.write(buf, 0, i); 064 } 065 input = baos.toByteArray(); 066 } 067 068 /** 069 * Add the rules previously loaded from the input stream into the 070 * specified digester. 071 */ 072 @Override 073 public void addRules(Digester d, String path) throws PluginException { 074 Log log = d.getLogger(); 075 boolean debug = log.isDebugEnabled(); 076 if (debug) { 077 log.debug( 078 "LoaderFromStream: loading rules for plugin at path [" 079 + path + "]"); 080 } 081 082 // Note that this input-source doesn't have any idea of its 083 // system id, so it has no way of resolving relative URLs 084 // such as the "include" feature of xmlrules. This is ok, 085 // because that doesn't work well with our approach of 086 // caching the input data in memory anyway. 087 088 InputSource source = new InputSource(new ByteArrayInputStream(input)); 089 FromXmlRuleSet ruleSet = new FromXmlRuleSet(source); 090 ruleSet.addRuleInstances(d, path); 091 } 092 } 093