/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.citrus.service.resource.filter;
import static com.alibaba.citrus.service.resource.ResourceLoadingService.*;
import static com.alibaba.citrus.util.Assert.*;
import static com.alibaba.citrus.util.StringUtil.*;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Set;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import com.alibaba.citrus.service.resource.Resource;
import com.alibaba.citrus.service.resource.ResourceFilter;
import com.alibaba.citrus.service.resource.ResourceFilterChain;
import com.alibaba.citrus.service.resource.ResourceLoadingOption;
import com.alibaba.citrus.service.resource.ResourceLoadingService;
import com.alibaba.citrus.service.resource.ResourceMatchResult;
import com.alibaba.citrus.service.resource.ResourceNotFoundException;
import com.alibaba.citrus.service.resource.support.ByteArrayResource;
import com.alibaba.citrus.service.resource.support.FileResource;
import com.alibaba.citrus.util.StringUtil;
import com.alibaba.citrus.util.io.StreamUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 将xml resource变换格式的filter。
*
* @author Michael Zhou
*/
public class XsltResourceFilter implements ResourceFilter {
private static final Logger log = LoggerFactory.getLogger(XsltResourceFilter.class);
private ResourceLoadingService resourceLoadingService;
private String xslt;
private String saveTo;
private File saveToDir;
private boolean failIfNotFound = true;
public void setXslt(String xslt) {
this.xslt = trimToNull(xslt);
}
public void setFailIfNotFound(boolean failIfNotFound) {
this.failIfNotFound = failIfNotFound;
}
public void setSaveTo(String saveTo) {
this.saveTo = StringUtil.trimToNull(saveTo);
}
public void init(ResourceLoadingService resourceLoadingService) {
this.resourceLoadingService = assertNotNull(resourceLoadingService, "resourceLoadingService");
assertNotNull(xslt, "missing xslt");
}
private File getSaveToDir() {
if (saveToDir != null) {
return saveToDir;
}
if (saveTo == null) {
return null;
}
File dir;
try {
dir = resourceLoadingService.getResourceAsFile(saveTo, FOR_CREATE);
if (!dir.exists()) {
dir.mkdirs();
}
} catch (ResourceNotFoundException e) {
throw new IllegalArgumentException("Specified saveTo dir is not exist: " + saveTo, e);
}
if (!dir.exists()) {
throw new IllegalArgumentException("Specified saveTo dir is not exist: " + saveTo);
}
saveToDir = dir;
log.debug("Transformed resource will be saved into directory: {}", dir.getAbsolutePath());
return saveToDir;
}
public Resource doFilter(ResourceMatchResult filterMatchResult, Set<ResourceLoadingOption> options,
ResourceFilterChain chain) throws ResourceNotFoundException {
String resourceName = filterMatchResult.getResourceName();
String xsltName = filterMatchResult.substitute(xslt);
Resource xsltRes;
try {
xsltRes = resourceLoadingService.getResource(xsltName);
} catch (ResourceNotFoundException e) {
xsltRes = null;
}
if (xsltRes == null && failIfNotFound) {
throw new ResourceNotFoundException("Could not find XSLT file for " + this + ", resourceName="
+ filterMatchResult.getResourceName());
}
Resource resource = chain.doFilter(filterMatchResult, options);
resource = transformDocument(resource, resourceName, xsltRes, xsltName);
if (getSaveToDir() != null) {
resource = saveToDir(resource, resourceName);
}
return resource;
}
/** 用XSLT转换XML资源。 */
private Resource transformDocument(Resource xmlRes, String xmlResName, Resource xsltRes, String xsltResName)
throws ResourceNotFoundException {
log.debug("Applying XSLT \"{}\" to resource \"{}\"", xsltResName, xmlResName);
try {
TransformerFactory factory = TransformerFactory.newInstance();
Source xsltSource = new StreamSource(xsltRes.getInputStream(), xsltResName);
Transformer transformer = factory.newTransformer(xsltSource);
Source source = new StreamSource(xmlRes.getInputStream(), xmlResName);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Result result = new StreamResult(baos);
transformer.transform(source, result);
return new ByteArrayResource(baos.toByteArray());
} catch (Exception e) {
throw new ResourceNotFoundException("Could not apply XSLT \"" + xsltResName + "\" to resource \""
+ xmlResName + "\"", e);
}
}
/** 将资源保存到目录中。 */
private Resource saveToDir(Resource resource, String resourceName) {
File fileToSave = new File(saveToDir, resourceName);
File parentDir = fileToSave.getParentFile();
if (!parentDir.exists()) {
parentDir.mkdirs();
}
if (!parentDir.exists()) {
log.warn("Directory to save is not exist: " + parentDir.getAbsolutePath());
return resource;
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(fileToSave);
StreamUtil.io(resource.getInputStream(), fos, true, true);
} catch (IOException e) {
log.warn("Could not save to file: " + fileToSave.getAbsolutePath(), e);
return resource;
}
Resource transformed = new FileResource(fileToSave);
if (log.isDebugEnabled()) {
log.debug("Transformed resource is saved to " + fileToSave.getAbsolutePath());
}
return transformed;
}
@Override
public String toString() {
return getClass().getSimpleName() + "[" + xslt + "]";
}
}