如何将pdf附加到另一个pdf中?露天

Question

如何将一个pdf附加到另一个中？

我尝试过使用这段代码，但当我尝试获取ContentInputStream时，会得到java.lang.NullPointerException。我做错了什么？如何将一个pdf附加到另一个？

PDDocument pdfTarget = null;
InputStream is = null;
InputStream tis = null;
for (ChildAssociationRef file: quotationsFiles) {
try {
NodeRef toAppend = file.getChildRef(); //workspace://SpacesStore/11bce382-45bf-4c67-95bc-a65361b323ef
ContentReader append = getReader(toAppend);
is = append.getContentInputStream(); // Here iam getting java.lang.NullPointerException 
NodeRef targetNodeRef = reportFile.getNodeRef();
ContentReader targetReader = getReader(targetNodeRef);
tis = targetReader.getContentInputStream();
String fileName = String.valueOf(serviceRegistry.getNodeService().getProperty(targetNodeRef, ContentModel.PROP_NAME));
// stream the document in
pdf = PDDocument.load(is);
pdfTarget = PDDocument.load(tis);
// Append the PDFs
PDFMergerUtility merger = new PDFMergerUtility();
merger.appendDocument(pdfTarget, pdf);
merger.setDestinationFileName(fileName);
merger.mergeDocuments();
} catch (Exception e) {
//throw new AlfrescoRuntimeException("IOException", e);
ColorLogUtil.debug(LOGGER, "IOException Error caused by :" + e);
}
}

private ContentReader getReader(NodeRef nodeRef) {
if (serviceRegistry.getNodeService().exists(nodeRef) == false) {
throw new AlfrescoRuntimeException("NodeRef: " + nodeRef + " does not exist");
}
QName typeQName = serviceRegistry.getNodeService().getType(nodeRef);
if (serviceRegistry.getDictionaryService().isSubClass(typeQName, ContentModel.TYPE_CONTENT) == false) {
throw new AlfrescoRuntimeException("The selected node is not a content node");
}
ContentReader contentReader = serviceRegistry.getContentService().getReader(nodeRef, ContentModel.PROP_CONTENT);
if (contentReader == null) {
throw new AlfrescoRuntimeException("The content reader for NodeRef: " + nodeRef + "is null");
}
return contentReader;
}

Answer 1

查看此代码是否适用于您：

public NodeRef mergePdfs(List<NodeRef> nodeRefList, String fileName,NodeRef destinationNode) 
throws FileNotFoundException,FileExistsException,Exception {
InputStream originalInputStream = null;
ContentReader reader = null;
NodeRef newDocNoderef = null;
PDFMergerUtility PDFmerger = new PDFMergerUtility();
ByteArrayOutputStream outputstream = new ByteArrayOutputStream();
try {
LOGGER.debug("Merging of Doc Started");
for (NodeRef node : nodeRefList) {
reader = contentService.getReader(node, ContentModel.PROP_CONTENT);
originalInputStream = reader.getContentInputStream();
PDFmerger.addSource(originalInputStream);
}
PDFmerger.setDestinationStream(outputstream);
PDFmerger.mergeDocuments();
if(originalInputStream!=null) {
originalInputStream.close();
}
newDocNoderef = writeContentToAlfresco(outputstream, nodeRefList, fileName,destinationNode);
LOGGER.debug("Documents are merged and new pdf is created at "+newDocNoderef);
} finally {
if(outputstream!=null)
outputstream.close();
}
return newDocNoderef;
}
public NodeRef writeContentToAlfresco(ByteArrayOutputStream outputstream, List<NodeRef> childRefList,
String fileName,NodeRef destinationNode) throws FileExistsException,IOException,Exception {
NodeRef pdf = null;
Map<QName, Serializable> props =  new HashMap<>();
Map<Date, NodeRef> dateMap = new HashMap<Date, NodeRef>();
NodeRef parentNodeRef=null;
try {
LOGGER.debug("Upload to Alfresco Started");
for(NodeRef noderef : childRefList) {
Date date = (Date) nodeService.getProperty(noderef, ContentModel.PROP_MODIFIED);
dateMap.put(date, noderef);
}
Map<Date, NodeRef> m1 = new TreeMap<Date, NodeRef>(dateMap);
Map.Entry<Date, NodeRef> entry = m1.entrySet().iterator().next();
NodeRef finalnodeRef = entry.getValue();
if(destinationNode!=null) {
parentNodeRef = destinationNode;
}else {
parentNodeRef = nodeService.getPrimaryParent(finalnodeRef).getParentRef();
}

QName[] myModelProps = CommonConstants.myModelProps;
for (QName myModelProp : myModelProps) {
Serializable object = nodeService.getProperty(finalnodeRef, myModelProp);
props.put(myModelProp, object);
}
FileInfo pdfInfo = fileFolderService.create(parentNodeRef, fileName + ".pdf",
MyModel.TYPE_CUSTOM_MYMODEL_TYPE);
pdf = pdfInfo.getNodeRef();
nodeService.setProperties(pdf,props);
nodeService.setProperty(pdf, ContentModel.PROP_TITLE,
nodeService.getProperty(finalnodeRef, ContentModel.PROP_TITLE));
nodeService.setProperty(pdf, ContentModel.PROP_DESCRIPTION, 
nodeService.getProperty(finalnodeRef, ContentModel.PROP_DESCRIPTION));
nodeService.setProperty(pdf,ContentModel.PROP_NAME,fileName + ".pdf");
ContentWriter writer = contentService.getWriter(pdf, ContentModel.PROP_CONTENT, true);
writer.setMimetype(MimetypeMap.MIMETYPE_PDF);
writer.setEncoding("UTF-8");
writer.putContent(new ByteArrayInputStream(outputstream.toByteArray()));
LOGGER.debug("Upload to Alfresco Ended");
}  catch(FileExistsException fee) {
ExceptionUtils.printRootCauseStackTrace(fee);
throw new FileExistsException(parentNodeRef, fileName);
}
catch (Exception e) {
ExceptionUtils.printRootCauseStackTrace(e);
throw new Exception(e);
} finally {
if (outputstream != null)
outputstream.close();
}
return pdf;
}

Answer 2

这似乎是我们在开箱即用的alfresco pdf工具包中支持的功能之一。你可以使用这个插件，也可以从支持它的代码中获得一些灵感