com.itextpdf.styledxmlparser.resolver.resource.ResourceResolver Maven / Gradle / Ivy
/*
This file is part of the iText (R) project.
Copyright (c) 1998-2023 Apryse Group NV
Authors: Apryse Software.
This program is offered under a commercial and under the AGPL license.
For commercial licensing, contact us at https://itextpdf.com/sales. For AGPL licensing, see below.
AGPL licensing:
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see
* If empty string or relative URI string is passed as base URI, then it will be resolved against current
* working directory of this application instance.
*
* @param baseUri base URI against which all relative resource URIs will be resolved
*/
public ResourceResolver(String baseUri) {
this(baseUri, null);
}
/**
* Creates a new {@link ResourceResolver} instance.
* If {@code baseUri} is a string that represents an absolute URI with any schema except "file" - resources
* url values will be resolved exactly as "new URL(baseUrl, uriString)". Otherwise base URI will be handled
* as path in local file system.
*
* If empty string or relative URI string is passed as base URI, then it will be resolved against current
* working directory of this application instance.
*
* @param baseUri base URI against which all relative resource URIs will be resolved
* @param retriever the resource retriever with the help of which data from resources will be retrieved
*/
public ResourceResolver(String baseUri, IResourceRetriever retriever) {
if (baseUri == null) {
baseUri = "";
}
this.uriResolver = new UriResolver(baseUri);
this.imageCache = new SimpleImageCache();
if (retriever == null) {
this.retriever = new DefaultResourceRetriever();
} else {
this.retriever = retriever;
}
}
/**
* Gets the resource retriever.
*
* The retriever is used to retrieve data from resources by URL.
*
* @return the resource retriever
*/
public IResourceRetriever getRetriever() {
return retriever;
}
/**
* Sets the resource retriever.
*
* The retriever is used to retrieve data from resources by URL.
*
* @param retriever the resource retriever
* @return the {@link ResourceResolver} instance
*/
public ResourceResolver setRetriever(IResourceRetriever retriever) {
this.retriever = retriever;
return this;
}
/**
* Retrieve image as either {@link PdfImageXObject}, or {@link com.itextpdf.kernel.pdf.xobject.PdfFormXObject}.
*
* @param src either link to file or base64 encoded stream
* @return PdfXObject on success, otherwise null
*/
public PdfXObject retrieveImage(String src) {
if (src != null) {
if (isContains64Mark(src)) {
PdfXObject imageXObject = tryResolveBase64ImageSource(src);
if (imageXObject != null) {
return imageXObject;
}
}
PdfXObject imageXObject = tryResolveUrlImageSource(src);
if (imageXObject != null) {
return imageXObject;
}
}
if (isDataSrc(src)) {
logger.error(MessageFormatUtil.format(
StyledXmlParserLogMessageConstant.UNABLE_TO_RETRIEVE_IMAGE_WITH_GIVEN_DATA_URI, src));
} else {
logger.error(MessageFormatUtil.format(
StyledXmlParserLogMessageConstant.UNABLE_TO_RETRIEVE_IMAGE_WITH_GIVEN_BASE_URI,
uriResolver.getBaseUri(), src));
}
return null;
}
/**
* Retrieve a resource as a byte array from a source that
* can either be a link to a file, or a base64 encoded {@link String}.
*
* @param src either link to file or base64 encoded stream
* @return byte[] on success, otherwise null
*/
public byte[] retrieveBytesFromResource(String src) {
byte[] bytes = retrieveBytesFromBase64Src(src);
if (bytes != null) {
return bytes;
}
try {
URL url = uriResolver.resolveAgainstBaseUri(src);
return retriever.getByteArrayByUrl(url);
} catch (Exception e) {
logger.error(MessageFormatUtil.format(
StyledXmlParserLogMessageConstant.UNABLE_TO_RETRIEVE_STREAM_WITH_GIVEN_BASE_URI,
uriResolver.getBaseUri(), src), e);
return null;
}
}
/**
* Retrieve the resource found in src as an InputStream
*
* @param src path to the resource
* @return InputStream for the resource on success, otherwise null
*/
public InputStream retrieveResourceAsInputStream(String src) {
byte[] bytes = retrieveBytesFromBase64Src(src);
if (bytes != null) {
return new ByteArrayInputStream(bytes);
}
try {
URL url = uriResolver.resolveAgainstBaseUri(src);
return retriever.getInputStreamByUrl(url);
} catch (Exception e) {
logger.error(MessageFormatUtil.format(
StyledXmlParserLogMessageConstant.UNABLE_TO_RETRIEVE_STREAM_WITH_GIVEN_BASE_URI,
uriResolver.getBaseUri(), src), e);
return null;
}
}
/**
* Checks if source is under data URI scheme. (eg data:[<media type>][;base64],<data>).
*
* @param src string to test
* @return true if source is under data URI scheme
*/
public static boolean isDataSrc(String src) {
return src != null && src.toLowerCase().startsWith(DATA_SCHEMA_PREFIX) && src.contains(",");
}
/**
* Resolves a given URI against the base URI.
*
* @param uri the uri
* @return the url
* @throws MalformedURLException the malformed URL exception
*/
public URL resolveAgainstBaseUri(String uri) throws MalformedURLException {
return uriResolver.resolveAgainstBaseUri(uri);
}
/**
* Resets the simple image cache.
*/
public void resetCache() {
imageCache.reset();
}
protected PdfXObject tryResolveBase64ImageSource(String src) {
try {
String fixedSrc = src.replaceAll("\\s", "");
fixedSrc = fixedSrc.substring(fixedSrc.indexOf(BASE64_IDENTIFIER) + BASE64_IDENTIFIER.length() + 1);
PdfXObject imageXObject = imageCache.getImage(fixedSrc);
if (imageXObject == null) {
imageXObject = new PdfImageXObject(ImageDataFactory.create(Base64.decode(fixedSrc)));
imageCache.putImage(fixedSrc, imageXObject);
}
return imageXObject;
} catch (Exception ignored) {
}
return null;
}
protected PdfXObject tryResolveUrlImageSource(String uri) {
try {
URL url = uriResolver.resolveAgainstBaseUri(uri);
String imageResolvedSrc = url.toExternalForm();
PdfXObject imageXObject = imageCache.getImage(imageResolvedSrc);
if (imageXObject == null) {
imageXObject = createImageByUrl(url);
if (imageXObject != null) {
imageCache.putImage(imageResolvedSrc, imageXObject);
}
}
return imageXObject;
} catch (Exception ignored) {
}
return null;
}
/**
* Create a iText XObject based on the image stored at the passed location.
*
* @param url location of the Image file.
* @return {@link PdfXObject} containing the Image loaded in.
* @throws Exception thrown if error occurred during fetching or constructing the image.
*/
protected PdfXObject createImageByUrl(URL url) throws Exception {
byte[] bytes = retriever.getByteArrayByUrl(url);
return bytes == null ? null : new PdfImageXObject(ImageDataFactory.create(bytes));
}
private byte[] retrieveBytesFromBase64Src(String src) {
if (isContains64Mark(src)) {
try {
String fixedSrc = src.replaceAll("\\s", "");
fixedSrc = fixedSrc.substring(fixedSrc.indexOf(BASE64_IDENTIFIER) + BASE64_IDENTIFIER.length() + 1);
return Base64.decode(fixedSrc);
} catch (Exception ignored) {
}
}
return null;
}
/**
* Checks if string contains base64 mark.
* It does not guarantee that src is a correct base64 data-string.
*
* @param src string to test
* @return true if string contains base64 mark
*/
private boolean isContains64Mark(String src) {
return src.contains(BASE64_IDENTIFIER);
}
}