8ba4ae9c11
- code refactoring:
if successful -> return the object ( Optional.ofNullable(request) )
if not successful -> throw an exception (instead of sending an error message on the queue)
- when calling 'convert()' method, catch this exception and send a T-Reply with error message on the queue
- add correlationID to error logs
Common code for Docker based ACS transformers
This project contains code that is common between all the ACS transformers that run within their own Docker containers. It performs common actions such as logging, throttling requests and handling the streaming of content to and from the container. It also provides structure and hook points to allow specific transformers to simply check request parameter and perform the transformation using either files or a pair of InputStream and OutputStream.
A transformer project is expected to provide the following files:
src/main/resources/templates/transformForm.html
src/main/java/org/alfresco/transformer/<XXX>Controller.java
src/main/java/org/alfresco/transformer/Application.java
- transformerForm.html - A simple test page using thymeleaf that gathers request parameters so they may be used to test the transformer.
<html xmlns:th="http://www.thymeleaf.org">
<body>
<div>
<h2>Test Transformation</h2>
<form method="POST" enctype="multipart/form-data" action="/transform">
<table>
<tr><td><div style="text-align:right">file *</div></td><td><input type="file" name="file" /></td></tr>
<tr><td><div style="text-align:right">targetFilename *</div></td><td><input type="text" name="targetFilename" value="" /></td></tr>
<tr><td><div style="text-align:right">width</div></td><td><input type="text" name="width" value="" /></td></tr>
<tr><td><div style="text-align:right">height</div></td><td><input type="text" name="height" value="" /></td></tr>
<tr><td><div style="text-align:right">allowPdfEnlargement</div></td><td><input type="checkbox" name="allowPdfEnlargement" value="true" /></td></tr>
<tr><td><div style="text-align:right">maintainPdfAspectRatio</div></td><td><input type="checkbox" name="maintainPdfAspectRatio" value="true" /></td></tr>
<tr><td><div style="text-align:right">page</div></td><td><input type="text" name="page" value="" /></td></tr>
<tr><td><div style="text-align:right">timeout</div></td><td><input type="text" name="timeout" value="" /></td></tr>
<tr><td></td><td><input type="submit" value="Transform" /></td></tr>
</table>
</form>
</div>
<div>
<a href="/log">Log entries</a>
</div>
</body>
</html>
- TransformerNameController.java - A Spring Boot Controller that extends AbstractTransformerController to handel a POST request to "/transform".
...
@Controller
public class AlfrescoPdfRendererController extends AbstractTransformerController
{
...
@PostMapping("/transform")
public ResponseEntity<Resource> transform(HttpServletRequest request,
@RequestParam("file") MultipartFile sourceMultipartFile,
@RequestParam("targetFilename") String targetFilename,
@RequestParam(value = "width", required = false) Integer width,
@RequestParam(value = "height", required = false) Integer height,
@RequestParam(value = "allowPdfEnlargement", required = false) Boolean allowPdfEnlargement,
@RequestParam(value = "maintainPdfAspectRatio", required = false) Boolean maintainPdfAspectRatio,
@RequestParam(value = "page", required = false) Integer page,
@RequestParam(value = "timeout", required = false) Long timeout)
{
try
{
File sourceFile = createSourceFile(request, sourceMultipartFile);
File targetFile = createTargetFile(request, targetFilename);
// Both files are deleted by TransformInterceptor.afterCompletion
StringJoiner args = new StringJoiner(" ");
if (width != null)
{
args.add("--width=" + width);
}
if (height != null)
{
args.add("--height=" + height);
}
if (allowPdfEnlargement != null && allowPdfEnlargement)
{
args.add("--allow-enlargement");
}
if (maintainPdfAspectRatio != null && maintainPdfAspectRatio)
{
args.add("--maintain-aspect-ratio");
}
if (page != null)
{
args.add("--page=" + page);
}
String options = args.toString();
LogEntry.setOptions(options);
Map<String, String> properties = new HashMap<>();
properties.put("options", options);
properties.put("source", sourceFile.getAbsolutePath());
properties.put("target", targetFile.getAbsolutePath());
executeTransformCommand(properties, targetFile, timeout);
return createAttachment(targetFilename, targetFile);
}
catch (UnsupportedEncodingException e)
{
throw new TransformException(500, "Filename encoding error", e);
}
}
}
- TransformerNameController#processTransform(File sourceFile, File targetFile, Map<String, String> transformOptions, Long timeout)
/transform (Consumes: application/json, Produces: application/json)
The new consumes and produces arguments have been specified in order to differentiate this endpoint from the previous one (which consumes multipart/form-data)
The endpoint should always receive a TransformationRequest and should always respond with a TransformationReply.
As specific transformers require specific arguments (e.g. transform for the Tika transformer) the request body should include this in the transformRequestOptions via the Map<String,String> transformRequestOptions.
Example request body
var transformRequest = {
"requestId": "1",
"sourceReference": "2f9ed237-c734-4366-8c8b-6001819169a4",
"sourceMediaType": "pdf",
"sourceSize": 123456,
"sourceExtension": "pdf",
"targetMediaType": "txt",
"targetExtension": "txt",
"clientType": "ACS",
"clientData": "Yo No Soy Marinero, Soy Capitan, Soy Capitan!",
"schema": 1,
"transformRequestOptions": {
"targetMimetype": "text/plain",
"targetEncoding": "UTF-8",
"transform": "PdfBox"
}
}
Example response body
var transformReply = {
"requestId": "1",
"status": 201,
"errorDetails": null,
"sourceReference": "2f9ed237-c734-4366-8c8b-6001819169a4",
"targetReference": "34d69ff0-7eaa-4741-8a9f-e1915e6995bf",
"clientType": "ACS",
"clientData": "Yo No Soy Marinero, Soy Capitan, Soy Capitan!",
"schema": 1
}
processTransform method
public abstract class AbstractTransformerController
{
void processTransform(File sourceFile, File targetFile, Map<String, String> transformOptions, Long timeout) { /* Perform the transformation*/ }
}
The abstract method is declared in the AbstractTransformerController and must be implemented by the specific controllers.
This method is called by the AbstractTransformerController directly in the new /transform endpoint which consumes application/json and produces application/json.
The method is responsible for performing the transformation. Upon a successful transformation it updates the targetFile parameter.
- Application.java - Spring Boot expects to find an Application in a project's source files. The following may be used:
package org.alfresco.transformer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application
{
public static void main(String[] args)
{
SpringApplication.run(Application.class, args);
}
}
Building and testing
The project can be built by running the Maven command:
mvn clean install
Artifacts
The artifacts can be obtained by:
- downloading from the Alfresco repository
- Adding a Maven dependency to your pom file.
<dependency>
<groupId>org.alfresco</groupId>
<artifactId>alfresco-transformer-base</artifactId>
<version>1.0</version>
</dependency>
and the Alfresco Maven repository:
<repository>
<id>alfresco-maven-repo</id>
<url>https://artifacts.alfresco.com/nexus/content/groups/public</url>
</repository>
The build plan is available in TravisCI.
Contributing guide
Please use this guide to make a contribution to the project.