001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.scxml.env.servlet; 018 019 import javax.servlet.ServletContext; 020 021 import org.apache.commons.scxml.PathResolver; 022 023 /** 024 * A wrapper around ServletContext that implements PathResolver. 025 * 026 * @see org.apache.commons.scxml.PathResolver 027 */ 028 public class ServletContextResolver implements PathResolver { 029 030 /** Cannot accept a null ServletContext, it will just throw 031 * NullPointerException down the road. */ 032 private static final String ERR_SERVLET_CTX_NULL = 033 "ServletContextResolver cannot be instantiated with a null" 034 + " ServletContext"; 035 036 /** The SevletContext we will use to resolve paths. */ 037 private ServletContext ctx = null; 038 039 /** 040 * Constructor. 041 * 042 * @param ctx The ServletContext instance for this web application. 043 */ 044 public ServletContextResolver(final ServletContext ctx) { 045 if (ctx == null) { 046 throw new IllegalArgumentException(ERR_SERVLET_CTX_NULL); 047 } 048 this.ctx = ctx; 049 } 050 051 /** 052 * Delegates to the underlying ServletContext's getRealPath(String). 053 * 054 * @param ctxPath context sensitive path, can be a relative URL 055 * @return resolved path (an absolute URL) or <code>null</code> 056 * @see org.apache.commons.scxml.PathResolver#resolvePath(java.lang.String) 057 */ 058 public String resolvePath(final String ctxPath) { 059 return ctx.getRealPath(ctxPath); 060 } 061 062 /** 063 * Retrieve the PathResolver rooted at the given path. 064 * 065 * @param ctxPath context sensitive path, can be a relative URL 066 * @return returns a new resolver rooted at ctxPath 067 * @see org.apache.commons.scxml.PathResolver#getResolver(java.lang.String) 068 */ 069 public PathResolver getResolver(final String ctxPath) { 070 return this; 071 } 072 073 } 074