001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry.engine.encoders; 016 017import org.apache.tapestry.Tapestry; 018import org.apache.tapestry.asset.AssetService; 019import org.apache.tapestry.engine.ServiceEncoder; 020import org.apache.tapestry.engine.ServiceEncoding; 021import org.apache.tapestry.services.ServiceConstants; 022 023/** 024 * Encoder for the {@link org.apache.tapestry.asset.AssetService} that uses servlet path info 025 * to store the resource digest and the path to the resource. 026 * 027 * @author Howard M. Lewis Ship 028 * @since 4.0 029 */ 030public class AssetEncoder implements ServiceEncoder 031{ 032 private String _path; 033 034 public void setPath(String path) 035 { 036 _path = path; 037 } 038 039 public void encode(ServiceEncoding encoding) 040 { 041 if (!encoding.getParameterValue(ServiceConstants.SERVICE).equals(Tapestry.ASSET_SERVICE)) 042 return; 043 044 String path = encoding.getParameterValue(AssetService.PATH); 045 String digest = encoding.getParameterValue(AssetService.DIGEST); 046 047 // _path ends with a slash, path starts with one. 048 049 String fullPath = _path + "/" + digest + path; 050 051 encoding.setServletPath(fullPath); 052 encoding.setParameterValue(AssetService.PATH, null); 053 encoding.setParameterValue(AssetService.DIGEST, null); 054 encoding.setParameterValue(ServiceConstants.SERVICE, null); 055 } 056 057 public void decode(ServiceEncoding encoding) 058 { 059 if (!encoding.getServletPath().equals(_path)) 060 return; 061 062 String pathInfo = encoding.getPathInfo(); 063 064 // The lead character is a slash, so find the next slash (the divider between the 065 // digest and the path). 066 int slashx = pathInfo.indexOf('/', 1); 067 068 encoding.setParameterValue(ServiceConstants.SERVICE, Tapestry.ASSET_SERVICE); 069 encoding.setParameterValue(AssetService.DIGEST, pathInfo.substring(1, slashx)); 070 encoding.setParameterValue(AssetService.PATH, pathInfo.substring(slashx)); 071 } 072 073}