File upload in JSF2 using base class

Surfing the net for JSF2 resources can be a tedious task. Actually for file upload I actually found a couple of blogs describing how to do it the firs I found actually only (FileUpload with JSF 2 and Servlet 3.0) made a taglib based on the second one. And it includes maven which I do not use.

I had to remake the example a bit since I got question to provide a sample application. When extracting the code I noticed it did not work anymore. The reason is probably the one mentioned at this blog: http://mcatr.blogspot.com/2010/01/multipart-requests-and-jsf.html.To make it work again, I did a solution that I am not happy with but it works. It takes the idea from this blog, joined with some from the other blogs mentioned. The former blog states that a multipart request to JSF 2 do not work, because it can not extract parameters from that kind of request.

The problem is that for what I actually wanted it was not right and one was a little bit overkill. So as usual I took another approach. I got some helf from Uploading files with JSF 2.0 and Servlet 3.0 but that solution includes making a custom component and renderer, and is dependant on classes found in Uploading files in Servlet 3.0. I actually copied all the code and tried it...but I got a failure when loading the page. So I wanted something with less code. and simpler to use, and I have a case when I am going to store vCards in a database so a solution to save the file on disk means I have to modify code anyway.

I took the following approach:

• Use standard html <input type="file" />
• Use @ManagedBean
• I first had a base class to handle the file and extended the Managed bean with this one, but since this stopped working I had to add:
• A Wrapper to wrap multipart requests
• A Filter to catch multipart request and transform them to the Wrapper type.
• I also have a FacesUtil class to simplify getting request and parameters

Here is the code:

In the view (vCardForm.xhtml)

<h:form enctype="multipart/form-data"> <input type="file" name="vcardFile"/> <h:commandButton action="#{vcardBean.uploadVCard}" value="Upload"/> </h:form>

Class to represent the uploaded file (UploadFile.java)

I created a class to store some information about the file being upload, I can later choose if I want to store to disk or in a database, for example sending this to an EJB and the EJB descides what to do.
package theironicprogrammer.model; public class UploadFile { private String fileName; private String contentType; privte byte[] fileData; public UploadFile(String fileName, String contentType, byte[] fileData){ this.fileName = fileName; this.contentType = contentType; this.fileData = fileData; } public String getFileName(){ return fileName; } public String getContentType(){ return contentType; } public byte[] getFileData(){ return fileData; } public void setFileName(String fileName){ this.fileName = fileName; } public void getContentType(String contentType){ this.contentType = contentType; } public void setFileData(byte[] fileData){ this.fileData = fileData; } }

The managed bean (VCardBean.java)

The interesting thing going on here is that i initialize the base class with the request for use of the request. Probably I could have done this in the constructor of the baseclass, but something you have to have to refactor.
package theironicprogrammer.model; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.Serializable; import java.util.logging.Level; import java.util.logging.Logger; import javax.annotation.PostConstruct; import javax.ejb.EJB; import javax.faces.bean.ManagedBean; import javax.faces.bean.RequestScoped; import javax.servlet.ServletOutputStream; import theironicprogrammer.session.PersonUpdaterLocal; import theironicprogrammer.http.MultiPart; /** * * @author theironicprogrammer@gmail.com */ @ManagedBean(name="vcardBean") @RequestScoped public class VCardBean implements Serializable{ @EJB PersonBean personBean; public String uploadVCard(){ System.out.println("uploadVCard..."); HttpServletRequest req = FacesUtil.getRequest(); if(req instanceof MultipartRequestWrapper){ MultipartRequestWrapper multi = (MultipartRequestWrapper)req; UploadFile uf = multi.findFile("vcardFile"); if(uf != null){ String fileExt = uf.getFileName().substring(uf.getFileName().lastIndexOf(".")); System.out.println("Extension" + fileExt); // should actually check the extension, but no big deal for example personBean.saveVCard(uf, "testuser"); FacesUtil.getFlash().put("messageCode", "vcard.upload.ok"); FacesUtil.getFlash().put("fileName", uf.getFileName()); } } return "vCardForm"; } public String findVCard(){ UploadFile uf = personBean.findVCard("testuser"); if(uf == null) { FacesUtil.getFlash().put("messageCode", "vcard.upload.err.load"); FacesUtil.getFlash().put("messageType", "errors"); } else { ServletOutputStream output = null; try { output = FacesUtil.getResponse().getOutputStream(); FacesUtil.getResponse().setHeader("Content-disposition", "attachment; filename=" + uf.getFileName()); FacesUtil.getResponse().setContentType(uf.getContentType()); ByteArrayOutputStream baos = new ByteArrayOutputStream(); baos.write(uf.getFileData()); FacesUtil.getResponse().setCharacterEncoding("UTF-8"); FacesUtil.getResponse().setContentLength(baos.size()); baos.writeTo(output); output.flush(); } catch (IOException ex) { FacesUtil.getFlash().put("messageCode", "vcard.upload.err.load"); FacesUtil.getFlash().put("messageType", "errors"); Logger.getLogger(VCardBean.class.getName()).log(Level.SEVERE, null, ex); } finally { try { output.close(); } catch (IOException ex) { FacesUtil.getFlash().put("messageCode", "vcard.upload.err.load"); FacesUtil.getFlash().put("messageType", "errors"); Logger.getLogger(VCardBean.class.getName()).log(Level.SEVERE, null, ex); } } } return "vCardForm"; } public String removeVCard(){ personBean.removeVCard("testuser"); FacesUtil.getFlash().put("messageCode", "vcard.remove.ok"); FacesUtil.getFlash().put("messageType", "messages"); return "vCardForm"; } }

MultipartRequestWrapper

package ironicprogrammer.http; import ironicprogrammer.model.UploadFile; import java.io.IOException; import java.util.Enumeration; import java.util.Hashtable; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.Part; /** * * @author theironicprogrammer@gmail.com */ public class MultipartRequestWrapper extends HttpServletRequestWrapper { private static final String CONTENT_DISPOSITION = "content-disposition"; private static final String CONTENT_DISPOSITION_FILENAME = "filename"; private Hashtable<String, String> params = new Hashtable<String, String>(); public MultipartRequestWrapper(HttpServletRequest request) { super(request); System.out.println("Created multipart wrapper...."); try { System.out.println("Looping parts"); for (Part p : request.getParts()) { System.out.println(String.format("Part name: %1$s, contentType : %2$s", p.getName(), p.getContentType())); for(String header : p.getHeaderNames()){ System.out.println("Header name : " + header + ", value : " + p.getHeader(header)); } byte[] b = new byte[(int) p.getSize()]; p.getInputStream().read(b); params.put(p.getName(), new String[]{new String(b)}); } } catch (IOException ex) { Logger.getLogger(MultipartRequestWrapper.class.getName()).log(Level.SEVERE, null, ex); } catch (ServletException ex) { Logger.getLogger(MultipartRequestWrapper.class.getName()).log(Level.SEVERE, null, ex); } } public UploadFile findFile(String attrName){ UploadFile uf = null; try { Part p = findPart(attrName); if(p != null){ String fileName = getFilename(p); System.out.println("Filename : " + fileName + ", contentType " + p.getContentType()); byte[] b = new byte[(int) p.getSize()]; p.getInputStream().read(b); params.put(p.getName(), new String[]{new String(b)}); uf = new UploadFile(fileName, p.getContentType(), b); } } catch (IOException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } return uf; } private Part findPart(String name){ HttpServletRequest request = (HttpServletRequest)getRequest(); Part p = null; try { for (Part part : request.getParts()) { if(part.getName().equals(name)){ p = part; break; } } } catch (IOException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } catch (ServletException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } return p; } private String getFilename(Part part) { for (String cd : part.getHeader(CONTENT_DISPOSITION).split(";")) { if (cd.trim().startsWith(CONTENT_DISPOSITION_FILENAME)) { return cd.substring(cd.indexOf('=') + 1).trim().replace("\"", ""); } } return null; } @Override public String getParameter(String name) { String [] values = getParameterValues(name); if(values == null || values.length == 0) { return null; } return values[0]; } @Override public Map<String, String> getParameterMap() { return params; } @Override public Enumeration<String> getParameterNames() { return params.keys(); } @Override public String[] getParameterValues(String name) { return params.get(name); } }

MultipartRequestFilter

package ironicprogrammer.http; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; /** * * @author theironicprogrammer@gmail.com */ @WebFilter(urlPatterns="/*") public class MultipartRequestFilter implements Filter{ private static final String REQUEST_METHOD_POST = "POST"; private static final String CONTENT_TYPE_MULTIPART = "multipart/"; public void init(FilterConfig filterConfig) throws ServletException { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest httpRequest = (HttpServletRequest) request; if(isMultipartRequest(httpRequest)){ System.out.println("Is multipart request.... wrapping it."); request = new MultipartRequestWrapper(httpRequest); } chain.doFilter(request, response); } public void destroy() { } public static final boolean isMultipartRequest(HttpServletRequest request) { return REQUEST_METHOD_POST.equalsIgnoreCase(request.getMethod()) && request.getContentType() != null && request.getContentType().toLowerCase().startsWith(CONTENT_TYPE_MULTIPART); } }

Session bean for handling the storage.

For the example this only stores it in the session.
package ironicprogrammer.session; import ironicprogrammer.model.UploadFile; import ironicprogrammer.utils.FacesUtil; import java.util.HashMap; import java.util.Map; import javax.ejb.Stateless; /** * * @author theironicprogrammer@gmail.com */ @Stateless public class PersonBean { /** * Saves a vcard for the person with supplied username */ public void saveVCard(UploadFile file, String username){ // Make use of session for example. No need to complicate with connection to filesystem or database System.out.println("Saving vcard for " + username); getVcards().put(username, file); } public UploadFile findVCard(String username){ System.out.println("Getting vcard for" + username); return getVcards().get(username); } public void removeVCard(String username){ System.out.println("Removing vcard for" + username); getVcards().remove(username); } private Map<String, UploadFile> getVcards(){ Map<String, UploadFile> vcards = (Map<String, UploadFile>)FacesUtil.getRequest().getSession().getAttribute("vcards"); if(vcards == null){ vcards = new HashMap<String, UploadFile>(); FacesUtil.getRequest().getSession().setAttribute("vcards", vcards); } return vcards; } }

Finally the class to inherit to make it all work

This is now obsolete, but I keep it in case JSF will handle the mutlipart form in the future. But even then it may not be needed.
package theironicprogrammer.http; import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.IOException; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.Part; import theironicprogrammer.model.UploadFile; /** * * @author theironicprogrammer@gmail.com */ public class MultiPart { private static final String CONTENT_DISPOSITION = "content-disposition"; private static final String CONTENT_DISPOSITION_FILENAME = "filename"; private HttpServletRequest request; protected MultiPart(){ } public UploadFile findFile(String attrName){ UploadFile uf = null; try { Part p = findPart(attrName); if(p != null){ String fileName = getFilename(p); System.out.println("Filename : " + fileName + ", contentType " + p.getContentType()); byte[] b = new byte[(int) p.getSize()]; p.getInputStream().read(b); uf = new UploadFile(fileName, p.getContentType(), b); } } catch (IOException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } return uf; } public HttpServletRequest getRequest() { return request; } public void setRequest(HttpServletRequest request) { this.request = request; } private Part findPart(String name){ Part p = null; try { for (Part part : request.getParts()) { if(part.getName().equals(name)){ p = part; break; } } } catch (IOException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } catch (ServletException ex) { Logger.getLogger(MultiPart.class.getName()).log(Level.SEVERE, null, ex); } return p; } private String getFilename(Part part) { for (String cd : part.getHeader(CONTENT_DISPOSITION).split(";")) { if (cd.trim().startsWith(CONTENT_DISPOSITION_FILENAME)) { return cd.substring(cd.indexOf('=') + 1).trim().replace("\"", ""); } } return null; } }
The only thing needed in the Managed bean is to call findFile("vcardFile") on the multipart request to get the file that is being uploaded and take action on that.

A sample project (for netbeans) can be found here: http://sites.google.com/site/ironicprogrammer/home/jsf-file-upload-example