ContentService - Alfresco Content Services - 23.4 - 23.4 - Ready - Alfresco - external

The ContentService provides an API for setting, accessing, and transforming content. You may want to read the content associated with a node, or transform the content from one format to another, for example from .ppt to .pdf. Methods provided by the API includes functionality to:

• Get obtainable transformers (to convert one mimetype to another)
• Get a suitable reader for a content type. The returned ContentReader will have a getContent method to actually read the content to a specified file.
• Get a suitable writer for a content type. The returned ContentWriter will have a putContent method to write the content to a specified file.
• Transform content from one mimetype to another.
• Get a transformer suitable for transforming images.
• Utility methods (for example to check size of content and free space in the content store).

Read plain text associated with a content NodeRef:

ContentReader reader = serviceRegistry.getContentService().getReader(nodeRef, ContentModel.PROP_CONTENT);

Reading binary content of a NodeRef:

ContentReader reader = serviceRegistry.getContentService().getReader(nodeRef, ContentModel.PROP_CONTENT);
InputStream originalInputStream = reader.getContentInputStream();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
finalint BUF_SIZE = 1 << 8; //1KiB buffer
byte[] buffer = newbyte[BUF_SIZE];
int bytesRead = -1;
while((bytesRead = originalInputStream.read(buffer)) > -1) {
    outputStream.write(buffer, 0, bytesRead);
}
originalInputStream.close();
byte[] binaryData = outputStream.toByteArray();

Writing data to a node’s content:

ContentWriter writer = serviceRegistry.getContentService().getWriter(nodeRef, ContentModel.PROP_CONTENT, true);
writer.putContent(new ByteArrayInputStream(content));

Writing a file’s data to a node’s content:

ContentWriter writer = serviceRegistry.getContentService().getWriter(nodeRef, ContentModel.PROP_CONTENT, true);
writer.setLocale(CONTENT_LOCALE);
File file = new File("c:/temp/images/BigCheese1.bmp");
writer.setMimetype("image/bmp");
writer.putContent(file);

Transforming a PPT to PDF (also works for other file formats):

ContentReader srcReader = serviceRegistry.getContentService().getReader(srcNodeRef, ContentModel.PROP_CONTENT);
ContentWriter pdfWriter = serviceRegistry.getContentService().getWriter(pdfNodeRef, ContentModel.PROP_CONTENT, true);
pdfWriter.setMimetype("application/pdf"); // new mimetype
pdfWriter.setEncoding(srcReader.getEncoding()); // original encoding
serviceRegistry.getSynchronousTransformClient().transform(srcReader, pdfWriter, Collections.emptyMap(), null, null);

Example of creating a new node and setting provided text content:

/**
* Creates a new content node setting the content provided.
*
* @param  parent   the parent node reference
* @param  name     the name of the newly created content object
* @param  text     the content text to be set on the newly created node
* @return NodeRef  node reference to the newly created content node
*/
private NodeRef createContentNode(NodeRef parent, String name, String text) {
    // Create a map to contain the values of the properties of the node
    Map<QName, Serializable> props = new HashMap<QName, Serializable>(1);
    props.put(ContentModel.PROP_NAME, name);
    
    // use the node service to create a new node
    NodeRef node = serviceRegistry.getNodeService().createNode(parent, ContentModel.ASSOC_CONTAINS, 
        QName.createQName(NamespaceService.CONTENT_MODEL_1_0_URI, name), ContentModel.TYPE_CONTENT, props).getChildRef();
    
    // Use the content service to set the content onto the newly created node
    ContentWriter writer = serviceRegistry.getContentService().getWriter(node, ContentModel.PROP_CONTENT, true);
    writer.setMimetype(MimetypeMap.MIMETYPE_TEXT_PLAIN);
    writer.setEncoding("UTF-8");
    writer.putContent(text);
    
    // Return a node reference to the newly created node
    return node;
}