001/* 002 * Copyright (c) 2006-2011 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * All rights reserved. This program and the accompanying materials 005 * are made available under the terms of the Eclipse Public License v1.0 006 * which accompanies this distribution, and is available at 007 * http://www.eclipse.org/legal/epl-v10.html 008 * 009 * Contributors: 010 * Nuxeo - initial API and implementation 011 * 012 * $Id$ 013 */ 014 015package org.nuxeo.ecm.core.convert.extension; 016 017import java.io.Serializable; 018import java.util.ArrayList; 019import java.util.List; 020import java.util.Map; 021 022import org.nuxeo.ecm.core.api.blobholder.BlobHolder; 023import org.nuxeo.ecm.core.convert.api.ConversionException; 024import org.nuxeo.ecm.core.convert.service.ConversionServiceImpl; 025import org.nuxeo.ecm.core.convert.service.MimeTypeTranslationHelper; 026import org.nuxeo.runtime.api.Framework; 027 028/** 029 * Specific {@link Converter} implementation that acts as a converters chain. 030 * <p> 031 * The chain can be: 032 * <ul> 033 * <li>a chain of mime-types 034 * <li>a chain of converter names 035 * </ul> 036 * <p> 037 * This depends on the properties of the descriptor. 038 * 039 * @author tiry 040 */ 041public class ChainedConverter implements Converter { 042 043 protected boolean subConvertersBased = false; 044 045 protected List<String> steps = new ArrayList<String>(); 046 047 protected List<String> subConverters = new ArrayList<String>(); 048 049 public ChainedConverter() { 050 subConvertersBased = false; 051 subConverters = null; 052 } 053 054 public ChainedConverter(List<String> subConverters) { 055 subConvertersBased = true; 056 this.subConverters = subConverters; 057 steps = null; 058 } 059 060 @Override 061 public BlobHolder convert(BlobHolder blobHolder, Map<String, Serializable> parameters) throws ConversionException { 062 063 if (subConvertersBased) { 064 return convertBasedSubConverters(blobHolder, parameters); 065 } else { 066 return convertBasedOnMimeTypes(blobHolder, parameters); 067 } 068 } 069 070 protected BlobHolder convertBasedSubConverters(BlobHolder blobHolder, Map<String, Serializable> parameters) 071 throws ConversionException { 072 String srcMT = blobHolder.getBlob().getMimeType(); 073 BlobHolder result = blobHolder; 074 for (String converterName : subConverters) { 075 ConverterDescriptor desc = ConversionServiceImpl.getConverterDescriptor(converterName); 076 if (!desc.getSourceMimeTypes().contains(srcMT)) { 077 throw new ConversionException("Conversion Chain is not well defined"); 078 } 079 Converter converter = ConversionServiceImpl.getConverter(converterName); 080 result = converter.convert(result, parameters); 081 srcMT = desc.getDestinationMimeType(); 082 } 083 return result; 084 } 085 086 /** 087 * Tries to find a chain of converters that fits the mime-types chain. 088 */ 089 protected BlobHolder convertBasedOnMimeTypes(BlobHolder blobHolder, Map<String, Serializable> parameters) 090 throws ConversionException { 091 String srcMT = blobHolder.getBlob().getMimeType(); 092 BlobHolder result = blobHolder; 093 for (String dstMT : steps) { 094 String converterName = Framework.getService(MimeTypeTranslationHelper.class).getConverterName(srcMT, dstMT); 095 if (converterName == null) { 096 throw new ConversionException( 097 "Chained conversion error : unable to find converter between " + srcMT + " and " + dstMT); 098 } 099 Converter converter = ConversionServiceImpl.getConverter(converterName); 100 result = converter.convert(result, parameters); 101 srcMT = dstMT; 102 } 103 return result; 104 } 105 106 @Override 107 public void init(ConverterDescriptor descriptor) { 108 if (!subConvertersBased) { 109 steps.addAll(descriptor.getSteps()); 110 steps.add(descriptor.getDestinationMimeType()); 111 } else { 112 ConverterDescriptor fconv = ConversionServiceImpl.getConverterDescriptor(subConverters.get(0)); 113 ConverterDescriptor lconv = ConversionServiceImpl.getConverterDescriptor(subConverters.get(subConverters.size() - 1)); 114 115 descriptor.sourceMimeTypes = fconv.sourceMimeTypes; 116 descriptor.destinationMimeType = lconv.destinationMimeType; 117 } 118 } 119 120 public List<String> getSteps() { 121 return steps; 122 } 123 124 /** 125 * Returns the sub converters of this chained converter. 126 * 127 * @since 5.9.2 128 */ 129 public List<String> getSubConverters() { 130 return subConverters; 131 } 132 133 /** 134 * Returns true if this chained converter is sub converters based, false otherwise. 135 * 136 * @since 5.9.4 137 */ 138 public boolean isSubConvertersBased() { 139 return subConvertersBased; 140 } 141}