Tratar Envio de PDF
Nesta parte, criaremos um servlet simples que é executado no AEM Publish para lidar com o envio de PDF do Acrobat/Reader. Esse servlet, por sua vez, fará uma solicitação HTTP POST para um servlet em execução em uma instância de autor AEM responsável por salvar os dados enviados como um nó nt:file no repositório do autor AEM.
Veja a seguir o código do servlet que processa o envio do PDF. Neste servlet, fazemos uma chamada de POST para um servlet montado em /bin/startworkflow em uma instância de Autor AEM. Esse servlet salva os dados do formulário no repositório do autor do AEM.
Servlet Publish para AEM
package com.aemforms.handlepdfsubmission.core.servlets;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.Servlet;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.osgi.service.component.annotations.Component;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@Component(
service={Servlet.class},
property={
"sling.servlet.methods=post",
"sling.servlet.paths=/bin/handlepdfsubmit"
}
)
public class HandlePDFSubmission extends SlingAllMethodsServlet {
private static Logger logger = LoggerFactory.getLogger(HandlePDFSubmission.class);
protected void doPost(SlingHttpServletRequest request,SlingHttpServletResponse response) {
ByteArrayOutputStream result = new ByteArrayOutputStream();
try {
ServletInputStream is = request.getInputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) != -1) {
result.write(buffer, 0, length);
}
logger.debug(result.toString(StandardCharsets.UTF_8.name()));
} catch (IOException e1) {
logger.error("An error occurred", e1);
}
HttpPost postReq = new HttpPost("http://localhost:4502/bin/startworkflow");
// This is the base64 encoding of the admin credetnials. This call should be made over HTTPS in production scenarios to avoid leaking credentials.
postReq.addHeader("Authorization", "Basic YWRtaW46YWRtaW4=");
CloseableHttpClient httpClient = HttpClients.createDefault();
List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
logger.debug("added url parameters");
try {
urlParameters.add(new BasicNameValuePair("xmlData", result.toString(StandardCharsets.UTF_8.name())));
postReq.setEntity(new UrlEncodedFormEntity(urlParameters));
httpClient.execute(postReq);
logger.debug("Sent request to author instance");
ServletOutputStream sout = response.getOutputStream();
sout.print("Your form was successfully submitted");
} catch (UnsupportedEncodingException | ClientProtocolException | IOException e) {
logger.error("An error occurred", e)
}
}
Servlet de autor AEM
A próxima etapa é armazenar os dados enviados no repositório do autor do AEM. O servlet montado em /bin/startworkflow salva os dados enviados.
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.UUID;
import javax.jcr.Binary;
import javax.jcr.Node;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.servlet.Servlet;
import javax.servlet.ServletOutputStream;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.mergeandfuse.getserviceuserresolver.GetResolver;
@Component(
service = {Servlet.class},
property = {
"sling.servlet.methods=get",
"sling.servlet.paths=/bin/startworkflow"
}
)
public class StartWorkflow extends SlingAllMethodsServlet {
private static Logger logger = LoggerFactory.getLogger(StartWorkflow.class);
@Reference
private GetResolver getResolver;
protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) {
String xmlData = null;
System.out.println("in start workflow");
response.setContentType("text/html;charset=UTF-8");
if (request.getParameter("xmlData") != null) {
logger.debug("The form was submitted from Acrobat/Reader");
xmlData = request.getParameter("xmlData");
System.out.println("in start workflow" + xmlData);
} else {
logger.debug("Mobile Form submission");
StringBuffer stringBuffer = new StringBuffer();
String line = null;
try {
InputStreamReader isReader = new InputStreamReader(request.getInputStream(), "UTF-8");
BufferedReader reader = new BufferedReader(isReader);
while ((line = reader.readLine()) != null)
stringBuffer.append(line);
} catch (Exception e) {
logger.debug("Error" + e.getMessage());
}
xmlData = new String(stringBuffer);
}
Resource r = getResolver.getFormsServiceResolver().getResource("/content/pdfsubmissions");
Session session = r.getResourceResolver().adaptTo(Session.class);
logger.debug("Got reosurce pdfsubmissions" + r.getPath());
UUID uidName = UUID.randomUUID();
Node xmlDataFilesNode = r.adaptTo(Node.class);
InputStream is = new ByteArrayInputStream(xmlData.getBytes());
Binary binary;
try {
Node xmlFileNode = xmlDataFilesNode.addNode(uidName.toString(), "nt:file");
logger.debug("Added nt file node");
Node jcrContent = xmlFileNode.addNode("jcr:content", "nt:resource");
logger.debug("Added jcr content");
binary = session.getValueFactory().createBinary(is);
jcrContent.setProperty("jcr:data", binary);
session.save();
} catch (RepositoryException e) {
logger.error("Unable to store data to JCR", e);
}
response.setContentType("text/plain;charset=UTF-8");
try {
ServletOutputStream sout = response.getOutputStream();
sout.print("Your form was successfully submitted");
} catch (IOException e) {
logger.error("Unable write response", e);
}
}
}
Um iniciador de fluxo de trabalho AEM é configurado para disparar sempre que um novo recurso do tipo nt:file for criado no nó /content/pdfsubmissions. Esse fluxo de trabalho criará um PDF não interativo ou estático ao mesclar os dados enviados com o modelo xdp. O pdf gerado é então atribuído a um usuário para análise e aprovação.
Para armazenar os dados enviados no nó /content/pdfsubmissions, usamos o serviço OSGi GetResolver, que nos permite salvar os dados enviados usando o usuário do sistema fd-service, disponível em cada instalação do AEM Forms.