Develop Reference

Why File uploading by custom java tag returns null

I am trying to write a java custom tag to uploaded file.But while uploading file it returns null as output.any help can appreciated
Tag Handler class:
public class SavePostTag extends SimpleTagSupport {
boolean isMultiPart;
public void doTag() throws JspException, IOException {
PageContext ctx = (PageContext)getJspContext();
HttpServletRequest request = (HttpServletRequest)ctx.getRequest();
try {
final Part tmpFile = request.getPart("file");
String fileName = request.getHeader("content-disposition");
ir.mahdiii.entity.File file = new ir.mahdiii.entity.File(Constant.repositoryPath + fileName, UrlGenerator.getInstance().generateRndUrl());
DbManager.getInstance().saveFileInfo(file);
FileOutputStream fileOutputStream = new FileOutputStream(file);
int tmp = 0;
FileInputStream fileInputstream = (FileInputStream)tmpFile.getInputStream();
while ((tmp = fileInputstream.read(new byte[1024])) != -1) {
fileOutputStream.write(tmp);
}
fileOutputStream.close();
} catch (ServletException | ClassNotFoundException | SQLException | NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
getJspContext().getOut().write("SUCCESS");
}
JSP file:
<c:if test="${param.status eq 'success'}">
<j:savepost/>
</c:if>
<div class="row">
<form action="/web/?page=admin&status=success" method="post" enctype="multipart/form-data">
<input type="file" name="file">
<input type="submit">
</form>
</div>
but at the line final Part **tmpFile = request.getPart("file"); it returns null.
any idea?

Retrieving values from a hash map in my JSP

Some background information of what I'm trying to achieve is a user hits the submit button on my JSP page it needs to send the message submitted to a text file and then I need to access the file and retrieve all the messages in the file in my JSP page. Please help me out, I have spent too long and I'm not sure what I need to do to be able to iterate over the hash map to show all the messages.
This is what my code looks like right now:
Controller:
public class TwitServlet extends HttpServlet {
#Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
String twits = "";
String path = getServletContext().getRealPath("/WEB-INF/twit.txt");
HttpSession session = request.getSession();
String tweet = request.getParameter("tweet");
System.out.print(tweet);
String usern = (String) session.getAttribute("user");
String alias = (String) session.getAttribute("uname");
twitDB.insert(tweet, usern, alias, path);
Map test = twitDB.getTwit("/Users/emilio/Desktop/twit.txt");
session.setAttribute("test",test);
getServletContext()
.getRequestDispatcher("/home.jsp").forward(request, response);
}
}
Database(using txtfile for now):
ublic class twitDB {
public static void insert (String twit, String user, String uname, String path) throws IOException {
Date date = new Date();
SimpleDateFormat ft = new SimpleDateFormat ("yyyy/MM/dd");
String dateString = ft.format(date);
File file = new File ("/Users/emilio/Desktop/twit.txt");
try ( PrintWriter out = new PrintWriter(new FileWriter(file, true))){
out.println("[#"+uname+"]:" + " " + dateString);
out.println(user);
out.println(twit);
out.println(".");
out.close();
}
catch (IOException iox) {
//do stuff with exception
iox.printStackTrace();
}
}
public static Map<String,Tweet> getTwit(String filename) throws IOException {
Map<String,Tweet> tweets = new HashMap<String,Tweet>();
File file = new File ("/Users/emilio/Desktop/twit.txt");
Scanner in = new Scanner(file);
while (in.hasNextLine()) {
String uname = in.nextLine();
String name = in.nextLine();
String twit = in.nextLine();
String filler = in.nextLine();
Tweet tweet = new Tweet(uname, name, twit);
tweets.put(uname, tweet);
tweets.put(name, tweet);
tweets.put(twit,tweet );
}
in.close();
return tweets;
}
}
Part of my JSP:
<button type="submit" method="post" class="btn btn-twitter">
<span class="glyphicon glyphicon-pencil"/>Tweet
</button>
</div>
</form>
</div>
</div>
<div class = "row feed">
<p>
<c:forEach items="${test}" var="test">
</c:forEach>
</p>

You are missing tag to do print if you are really getting data from the server.
<c:forEach items="${test}" var="test">
<c:out value="${test}"/>
</c:forEach>

How to receive info to put in HTML/JSP from post servlet

Basically my goal for this page I'm working on is for users to type in a stock symbol and this information goes to a post method and send back the data to put on the same html/jsp page. I have been able to get this to work where the form leads to another JSP page, but that has to be a separate page, I'd like to be able to stay on the same page and have the info come up. If you have a resource that could teach me how to deal with this problem, I would appreciate that just as much as a solution. I have been using the Gradle Build Tool.
Here is the form(in index.jsp):
<h1>Search Stock</h1>
<form method="POST" action="DataPage.jsp">
<input type = "text" name = "Symbol">
<input type = "submit" name = "getData">
</form>
Here is the functioning JSP code(DataPage.jsp):
<%
String Ticker = request.getParameter("Symbol");
PrintWriter write = response.getWriter();
if((Ticker == null)){
String message = "Please enter a stock symbol";
write.println(message);
}else{
try{
Company object = Serializing.getCompany(Ticker);
object.updateData();
write.println("data last added" + object.getLastUpdate());
write.println(object.getSentiment());
}catch(NullPointerException x){
Company object = Serializing.getCompany(Ticker);
}
}%>
Here is the servlet I tried writing(DataServlet.java), I have very little experience with servlets, I scavenged this from different sources and questions on stackoverflow:
package Default;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/**
* Created by Ceyer on 9/3/2015.
*/
#javax.servlet.annotation.WebServlet(name = "DataServlet", urlPatterns = ("/"))
public class DataServlet extends javax.servlet.http.HttpServlet {
private static final long serialVersionUID = 1L;
public DataServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {
String Ticker = request.getParameter("Symbol");
if ((Ticker == null)||Ticker.trim().isEmpty()) {
String message = "Please enter a stock symbol";
request.setAttribute("data", message);
getServletContext().getRequestDispatcher("/login.jsp").forward(request, response);
} else {
PrintWriter write = response.getWriter();
try {
Company object = Serializing.getCompany(Ticker);
object.updateData();
request.setAttribute("data", object.getSentiment() + "updated last" + object.getLastUpdate());
getServletContext().getRequestDispatcher("/login.jsp").forward(request, response);
} catch (NullPointerException x) {
Company object = Serializing.getCompany(Ticker);
request.setAttribute("data", "We do not have info on this stock");
getServletContext().getRequestDispatcher("/login.jsp").forward(request, response);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

If you want to use only one page and with a servlet, I think you can use session and response.sendRedirect() to do it.
This is index.jsp page
<h1>Search Stock</h1>
<form method="POST" action="DataServlet" onsubmit="dataCheck()">
<input type="text" name="Symbol">
<input type="submit" value="getData">
</form>
<%
if(session.getAttribute("data") != null) {
out.print("<p>" + session.getAttribute("data"));
session.removeAttribute("data");
}
%>
<script>
function dataCheck() {
if(document.getElementsByName[0].value == ""){
alert("Symbol is null!");
return false;
}
return true;
}
</script>
This is DataServlet class
public class DataServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String Ticker = request.getParameter("Symbol");
Company object = Serializing.getCompany(Ticker);
if (object != null) {
object.updateData();
request.getSession().setAttribute("data", object.getSentiment() +
"updated last" + object.getLastUpdate());
} else {
request.getSession().setAttribute("data", "We do not have info on this stock");
}
response.sendRedirect("index.jsp");
}
}

How to upload file in relative directory

I have made a application where we can upload any file which will save in our local given directory. I want to modify it, i want to add a drop down (with multiple option i.e floor, store, section) for department. i.e if we want to upload a file in 'Store' folder, we can choose 'Store' option and the file will uploaded to the 'Store' folder. Same for 'Floor' and 'Section'.
I just need any example link for that.
i have made it in liferay.
import org.apache.commons.io.FileUtils;
import com.liferay.portal.kernel.upload.UploadPortletRequest;
import com.liferay.portal.util.PortalUtil;
import com.liferay.util.bridges.mvc.MVCPortlet;
public class UploadDirectory extends MVCPortlet {
private final static int ONE_GB = 1073741824;
private final static String baseDir = "/home/xxcompny/workspace";
private final static String fileInputName = "fileupload";
public void upload(ActionRequest request, ActionResponse response)
throws Exception {
UploadPortletRequest uploadRequest = PortalUtil.getUploadPortletRequest(request);
long sizeInBytes = uploadRequest.getSize(fileInputName);
if (uploadRequest.getSize(fileInputName) == 0) {
throw new Exception("Received file is 0 bytes!");
}
File uploadedFile = uploadRequest.getFile(fileInputName);
String sourceFileName = uploadRequest.getFileName(fileInputName);
File folder = new File(baseDir);
if (folder.getUsableSpace() < ONE_GB) {
throw new Exception("Out of disk space!");
}
File filePath = new File(folder.getAbsolutePath() + File.separator + sourceFileName);
FileUtils.copyFile(uploadedFile, filePath);
}
}
JSP is here
<%# taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %>
<%# taglib uri="http://liferay.com/tld/aui" prefix="aui"%>
<%# taglib uri="http://liferay.com/tld/ui" prefix="liferay-ui"%>
<portlet:defineObjects />
<portlet:actionURL name="upload" var="uploadFileURL"></portlet:actionURL>
<aui:form action="<%= uploadFileURL %>" enctype="multipart/form-data" method="post">
<select name="folder">
<option value="store">Store</option>
<option value="floor">Floor</option>
<option value="department">Department</option>
</select>
<aui:input type="file" name="fileupload" />
<aui:button name="Save" value="Save" type="submit" />
</aui:form>
i want the file will upload in the belonging folder.

I had somewhat similar task to upload files to specified folders, so following is bit modified code as per your requirement:
public void upload(ActionRequest request, ActionResponse response)
throws Exception {
UploadPortletRequest uploadRequest = PortalUtil.getUploadPortletRequest(request);
long sizeInBytes = uploadRequest.getSize(fileInputName);
if (sizeInBytes == 0) {
throw new Exception("Received file is 0 bytes!");
}
File uploadedFile = uploadRequest.getFile(fileInputName);
String sourceFileName = uploadRequest.getFileName(fileInputName);
/* selected folder from UI */
String paramFolder = uploadRequest.getParameter("folder");
byte[] bytes = FileUtil.getBytes(uploadedFile);
if (bytes != null && bytes.length > 0) {
try {
/* Create folder if doesn't exist */
File folder = new File(baseDir + File.separator + paramFolder);
if (!folder.exists()) {
folder.mkdir();
}
/* Write file to specified location */
File newFile = new File(folder.getAbsolutePath() + File.separator + sourceFileName);
FileOutputStream fileOutputStream = new FileOutputStream(newFile);
fileOutputStream.write(bytes, 0, bytes.length);
fileOutputStream.close();
newFile = null;
} catch (FileNotFoundException fnf) {
newFile = null;
/* log exception */
} catch (IOException io) {
newFile = null;
/* log exception */
}
}
}

You can use the below code
String user_selected_option=request.getParameter("userSel")
realPath = getServletContext().getRealPath("/files");
destinationDir = new File(realPath+"/"+user_selected_option);
// save to destinationDir

Apache File upload, FileItemIterator is empty

I want a simple image capture/upload on mobile devices. For the actual file upload, i use Apache Commons. Now I encountered the same problem as described here: Apache commons fileupload FileItemIterator hasNext() returns false, but I can't find out where the request might have been consumed before my post method.
I tested it on my development machine, when i put in any file (image or not), the iterator is simpy empty.
Here is everything I have, I marked the actual file upload code so you don't have to sift through everything.
Thanks for the help!
#WebServlet("/scanner")
public class MyServiceServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final int maxFileSize = 50 * 1024;
private static final int maxMemSize = 4 * 1024;
private static final String saveFolder = "/";
private final String repoFolder;
private final DiskFileItemFactory factory;
public MyServiceServlet() {
final String os = System.getProperty("os.name");
if (os.contains("Windows"))
repoFolder = "C:\\temp";
else
repoFolder = "/tmp";
factory = new DiskFileItemFactory();
factory.setSizeThreshold(maxMemSize);
// Location to save data that is larger than maxMemSize.
factory.setRepository(new File(this.repoFolder));
}
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("get");
request.getRequestDispatcher("MyService/start.html").forward(request, response);
}
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("Post");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>MyService</title>");
out.println("</head>");
out.println("<body>");
if (!ServletFileUpload.isMultipartContent(request)) {
out.println("<p>Nothing uploaded</p>");
} else {
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// maximum file size to be uploaded.
upload.setSizeMax(maxFileSize);
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!FILE UPLOAD HERE
try {
FileItemIterator it = upload.getItemIterator(request);
while (it.hasNext()) {
FileItem item = (FileItem) it.next();
if (!item.isFormField()) {
String fileName = item.getName();
String contentType = item.getContentType();
boolean isInMemory = item.isInMemory();
long sizeInBytes = item.getSize();
file = new File(saveFolder + fileName);
item.write(file);
System.out.println(file);
}
}
} catch (Exception e) {
e.printStackTrace();
}
this.printUserForm(out);
}
out.println("</body>");
out.println("</html>");
}
}
start.html file, I may have missed something here
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>MyService</title>
</head>
<body>
<form enctype="multipart/form-data" method="post" name="input" action="/MySercice/scanner">
<input type="file" accept="image/*;capture=camera"></input>
<input type="submit" value="upload">
</form>
</body>
</html>
web.xml, if it helps. But there is nothing here, really
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name>MyService</display-name>
<welcome-file-list>
<welcome-file>start.html</welcome-file>
</welcome-file-list>
</web-app>

Try with this:
if (ServletFileUpload.isMultipartContent(request)) {
try {
List<FileItem> multiparts = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);
for (FileItem item : multiparts) {
if (!item.isFormField()) {

For those who use Seam:
Following #CR7 suggestion, I could make it work by adding the below config to the components.xml
<web:multipart-filter create-temp-files="true"
max-request-size="1024000" url-pattern="*"/>
Ps: I don't know why, but for me, any other value I put in url-pattern makes the list returns empty.