I would like to understand how does multipart/form-data works during file upload scenario's, Does it chunks the data from client to server while transferring the files ?
View RepliesI am using apache-commons-fileupload to get file from client to the server.(using JSP and Servlet).
JSP/HTML
<form method="POST" action="GetFile" enctype="multipart/form-data">
<input type="file" name="datafile">
<input type="text" name="text1">
<input type="submit" value="Next">
</form>
Servlet: GetFile
System.out.println(request.getParameter("text1"));
I am able to upload the file to the server, but I am not able to get the value of text1 in the servlet (I am getting null value of text1 in the servlet), I need this textfield in the form to submit some additional information while uploading it to the server.
--> Is enctype="multipart/form-data" option of form doesn't allow other form data to be submited? if it doesn't allow it then what are the other options I have to send this additional textfield to the server.
--> Or is there any other problem in my code?
I am learning few concepts in servlets. And i came across this doubt. We used to send data over network using httpsession as below.
HttpSession session = request.getSession();
Object obj = new Object();
session.setAttribute("object", obj);
And get the data in JSP with below code
<%= session.getAttribute("object")%>
However I am not sure whether HTTPSession is serializable or not.
How HTTPSession works?
I want to understand how is it possible to send data (image + text) along a single form. Here is my code:
<form method="post" action="updateAccount"
encType="multipart/form-data">
<input type="file" name="file" value="Select image ..." /> <input
type="submit" value="Start Upload" /> <br>
<textarea rows="8" cols="54" name="about">Yes
Iam trying to upload jpeg image.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
[Code] ....
In servlet the below code
DataInputStream din = new DataInputStream(request.getInputStream());
byte[] data = new byte[0];
byte[] buffer = new byte[50];
int bytesRead;
while ((bytesRead = din.read(buffer)) > 0 ) {
byte[] nData = new byte[data.length + bytesRead];
System.arraycopy(data, 0, nData, 0, data.length);
System.arraycopy(buffer, 0, nData, data.length, bytesRead);
data = newData;
}
What i see is servletinput stream does't have any values.It does't even enter while loop.
I'm new to json and the web. My purpose is to use json data from a server and parse it and show meaningful data to the user. I am aware of json parsing, so no sweat there. However, I would like to know how json data is sent to the front end after which it can be parsed.
Usually in my json parsing examples, I have a variable like var data = ]OR I do a getJSON on a data.json file which I have stored in the project folder. However, I want this data to come real time from a servlet. How to go about this?
So, basically my question is, how do I send real time json data from a servlet backend, say some records which I have extracted from the database using jdbc?
Our client has a user facing web application running on Jboss. There is a separate admin application (in its own ear) but deployed on same Jboss server on which user facing web application is running.
They need a screen to upload large amount of data into database. Their original files were in excel with size > 60 mb. We suggested following to them:
a. Change upload format to CSV - this brought down file sizes to 25-30 mb
b. Upload process will be MDB - asynchronous processing of data so that admin web app does not stop responding
We also suggested following to them:
a. Host admin app on a different machine so that user facing site does not respond slow during data processing
b. We can provide incremental upload feature and they should upload files in the chunks of 4-5 mb, specifically if they have user a web page to upload such files - they don't buy this argument though.
c. Data processing can be a separate script instead of a part of admin web application. They can FTP files to a designated location and this script will process those files.
I have following questions:
Q1 - Have you seen upload of such large datafiles to a web application? I see sites like Zoho CRM or Salesforce do not support such data imports and mostly fail or not respond.
Q2 - Is there a set of guidelines/best practices to upload large data files of this nature? How do insurance companies or others with enormous set of data accomplish such tasks (what is the architecture of such programs)?
I have an html form with 200 input fields of type text. The first input field contains the name of a book author and the remaining 199 fields hold each a title of a book that he or she has written. I also have a servlet that processes the form data and sends it to a file. The entered data is restricted to a combination of the characters "a...z A...Z". how do i go about with creating my html page. The input fields are just too many, how to retrieve the 200 values in servlet.
<html>
<head>
<script>
var k;
function testField(Expression){
k=1;
var str1="abcdefghijklmnopqrstuvwxyz ";
var sor=Expression;
[code]....
I have a very simple HTML form with a textField for a name, and add button to add the name to a MySQL database, and a sort button to sort the names in the database and display them. I almost have it working, however when I hit the "sort" button; I get the message that appears after a user clicks the add button along with the sorted list of names. It looks like this:
Please go back and add a name or sort.
Bill Jones
David G
Debbie Downer
Jane Doe
Joe Smith
John Doe
Mike Jones
Paul Smith
Susan Jones
What I have to change on my code to make just the list show up by itself when the user clicks sort?
My servlet code:
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
[Code] .....
I am currently working on a module where huge amount of data needs to be sent to the weblogic server. The limit on Weblogic-> Server - > Protocols is 10MB.
The huge data is coming when i try to add more than 20 rows to the Ajax request.
There are possible two solutions for this
1) Increase the limit on Weblogic server to 1Gb which might lead to server crash when two or more users are trying to add 100 records at the same time.
2) Send memory in the form of chunks of (length of a row) every time I add a row. Store this in session and upon form submission retrieve from session. This cannot work if there are more than 20 users doing load testing as increase in session data decrease performance gradually.
I need that data passed to my server without any performance or errors.Currently its showing weblogic.socket.MaxMesssageSizeExceededException and RequestURI too long errors.
I am not able to send large binary data from Java WebSocket client to Java WebSocket server. However, 1KB data transfer is working. Below is my code:
Client:
RandomAccessFile aFile = new RandomAccessFile
("c: est.txt", "r");
FileChannel inChannel = aFile.getChannel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
while(inChannel.read(buffer) > 0)
{
session.getBasicRemote().sendBinary(buffer, false);
[code]...
Give me an example of WebSocket sample for large binary data transfer.
I got my first project in which i need to receive some data from multiple client on network regularly(say every second) and then process that data and stored it to the database and then GUI needs to be created which display data accordingly.
While thinking for the design i thought blocking queue to implement the same. Like producer receive data from the port into a string builder and put that into the LinkedBlockingQueue. Consumer will take this data , process some work on it and store it into the database.I am using sybase ase 15 as a database.
My question is as i am receiving data very frequently which require insertion , updation and search almost every second into the database. What is the best way to improve the performance.
say i have 2 types of data is coming one having keyword 'Alarm' and other having 'ceased' so i need to use something like this
common fields in both is name and number.
if (ceased)
search into the database for particular event for which this ceased receive using name and numbe rand update the another field into it Also make separate entry for it
else
make a entry
Also as i am using 2-3 thread for consumers and thread = Number of client for the producer. So i thought to use synchronization at the consumer side which writes data into the database such that only 1 thread can write it.
I need to get the html in string when i hit the hit the jsp in servlets basically i need to put the output of jsp in pdf file when i hit one link i need to download that data in pdf file. I am using itextpdf.
Sample code
pResponse.setContentType("application/pdf");
((HttpServletResponse) pResponse).setHeader("Content-Disposition", "attachment; filename=report.pdf");
//Get the output stream for writing PDF object
OutputStream outStream=pResponse.getOutputStream();
ByteArrayOutputStream baosPDF = new ByteArrayOutputStream();
[Code] ....
I need to convert the sample download.jsp to html so that i can parse
// XMLWorkerHelper.getInstance().parseXHtml(docWriter, document,new FileInputStream(jspPath),new FileInputStream(csspath) ,null ,new XMLWorkerFontProvider());
In my web application i want to upload file to drop-box. I am getting file name from browser.Is it possible to upload file to drop-box with only file name.
Below the drop-box upload code with java.
File inputFile = new File("New Text Document.txt");
System.out.println("inputFile.getAbsoluteFile(): " + inputFile);
FileInputStream inputStream = new FileInputStream(inputFile);
try {
DbxEntry.File uploadedFile = client.uploadFile("/magnum-opus.txt",
DbxWriteMode.add(), inputFile.length(), inputStream);
System.out.println("Uploaded: " + uploadedFile.toString());
} finally {
inputStream.close();
}
In the above code the place New Text Document.txt we have to provide total path of file.
By using FileReader, FileWriter and their constituents, I am creating a file to contain employee information ( name, age, hours, etc. ). The user is to input all of the data on a single line and we were asked to implement StringTokenizer to assign that data to the file. I have never used the StringTokenizer before, but I have a rough idea how it is to function. I used pw.println to test what I have so far, now I would like to let the user build the initial file with the "first employees" of the company, and then view the file, and then go back and append new employee data to that same file. My question is, how can I take the user input as a StringTokenizer and add that to the file?
In the for loop below, I thought I would see if it would work, but it does not. The loop only executes once and does not allow me to enter data.
public class Records {
public static void main(String [] args) throws IOException {
Scanner input = new Scanner(System.in);
FileWriter fw = new FileWriter("dbs3.java");
BufferedWriter bw = new BufferedWriter(fw);
PrintWriter pw = new PrintWriter(bw);
System.out.println("NEW EMPLOYEE DATA SHEET");
System.out.print("Number of new employees: ");
int number = input.nextInt();
[Code] ....
Recently we got an issue about file download. We are using below code to fetch the data from backend(DB2) and export to excel.
Before Jan 15 it use to take 2 minutes to download the file (2 MB size). But now its taking half an hour to download.
response.setContentType("application/vnd.ms-excel");
response.setHeader("content-disposition","attachment; filename=Attendance_Report.xls");
We have restarted server, system but still problem exists. We found that there is no code level or data base level or network level issues.
Now we have to see server level issue. What are the factors which effects the file downloading at server level.
We are using websphere 6.1 ,java1.4
How to upload file to google drive using java. my java code is.
HttpTransport httpTransport = new NetHttpTransport();
JsonFactory jsonFactory = new JacksonFactory();
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
httpTransport, jsonFactory, CLIENT_ID, CLIENT_SECRET, Arrays.asList(DriveScopes.DRIVE))
.setAccessType("online")
.setApprovalPrompt("auto").build();
[Code] ....
So in that file object(java.io.File fileContent = new java.io.File("document.txt");) asking complete file path. But in file upload we can get only file name not path.
I am creating a program where it reads the data inside a file and then places this data into arrays. The file I created has numbers 1-30 in it, file named, testing1.txt .
Java Code:
public static void main(String[] args) {
// TODO Auto-generated method stub
// Variables Declaration Section
//******************************
BufferedReader br;
String sCurrentLine;
String str;
[Code] ....
My issue is that the 'str' value is not initialized, but if I initialize it, it ruins the code. I'm not sure what to do in the situation.
I have a requirement where a large file (100 -200MB) is uploaded from the client to a content management system. I am using a servlet with Apache Commons File Upload API. Apache FileUpload has 2 ways of handling files,
1) Non-Streaming
2) Streaming
Currently I use the Non-Streaming approach where the servlet stores the file in a temp location and upload the same into the content management system - This is taking lot of time so I am trying to implement Streaming API.
Content Management API supports streaming in 2 methods,
a) SetContent - Takes the file's ByteArrayOutputStream as input -> This gives OutOfMemoryException because the file being large
b) AppendContent - Takes the file's ByteArrayOutputStream as input -> This method can be called multiple times to upload the large file but I dont know how to do this. The Apache File Upload gives InputStream of the file and I need to split that into chuncks and append into the content management system.
How to convert InputStream to 4KB ByteArrayOutputStream so that I can use the AppendContent method in content management API?
I am trying to connect to a local service over UDP - the simulator works fine, but my code does not... The sender is a separate thread and I have tried blocking, non-blocking, connecting, not connection, reading and re-reading the Oracle docs,
Java Code:
package my.comm;
import my.myMethods;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
[code]....
I have a code that uploads files in server after browsing folders and files then get the paths of files but I have a problem in getting the paths
List items = upload.parseRequest(request);
Iterator iterator = items.iterator();
while (iterator.hasNext()) {
FileItem item = (FileItem) iterator.next();
if (!item.isFormField())
{ fileName = item.getName();
root = getServletContext().getRealPath("/");
path = new File(root + "/uploads");
[Code]...
list1 must has paths that I want but I do not get the paths of upload files
I'm using netbeans to develop an application to send and receive data via RS 232 standard. I can send data but I can't read it.what can I do? I have this message in the console: Underlying input stream returned zero bytes. (I must use also threads to have application in real time but I don't understand very well....
View Replies View RelatedI'm creating a web applicaion. for that i want to create a registration page. and this registration details have to be stored in the database.
I'm getting the below error while trying to send the data ...
The requested resource (/cmd/InsertRegtodb) is not available.
Here cmd is project name and InsertRegtodb is servlet name.
Actually the servlet is present is the mentioned address. but it is not connecting to it
There is one more servlet in the same folder and which is accessible from another jsp. But this servlet is not accessible even though i have used same code as it is used for the servlet which worked for me previously...
I written java code in JSP to display data. I know it is bad practice. Actually my Business-service communicates with DB and returning data in the form of MAP. I don't have beans Because the fields in DB is dynamically changing. So, for now I'm retrieving Data by writing Java code in JSP. Is there any other way to display data without writing java code in JSP?
View Replies View RelatedI am trying to develop a new web application which takes in data from a form and stores data in a database.I have included all the three files join.jsp(the form which takes in data),reg.java(servlet) and JavaConncetDb(method which connects db and servlet). I get a 404 error when i try load the web application.
My file structure in eclipse
The error I am getting
join.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
[Code] .....
I'm getting ready to code a program that takes record of items loaned and return in a table. I want more than one user to access the program to be able to update the data in the table. For instance, if one user added 5 new items to the table, all other users would be able open the program to see a modified table with 5 new items. Was looking for some advice and was wondering if implementing a database would work best.
View Replies View Related