I have been trying to implement custom request method in HTTP header while posting my data to the server URL. My application specific URL accepts -X parameter and -d for the data and it is mandatory for that url. Basically I am trying to dump JSON data into my influx DB using CURL command which is working fine from the shell. But the issue is, if I am implementing the same in java with proper approach, it is not supported or working. My CURL command is :
curl -X POST -d '<my_json_data>' '<my_url>'
How can I implement the same in java using HttpUrlConnection or other available approach?
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 ?
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.
I have a servlet that adds entries to a table and when there is a duplicate it redirects to an error page and I'd like to make it display the duplicate entry id.The problem is when I try to get the parameter and show the error (the duplicate entry id) on my jsp error page it shows null instead of the appropriate number.this is my servlet:
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;
I have a basic HTML calculator that asks the user to input 2 integers and select from a dropdown their desired math operation:
The servlet will process the calculation and counts how many times a certain operation has been used:
The counter for Multiplication has incremented accordingly.
HTML: <form action = "processcalc.html" method = "post"> <table> <tr> <td>First Operand:</td> <td><input type = "text" name = "firstOperand" required></td>
[Code] ....
Question: However, when I press "Go Back" and process a new computation, all counters reset to 0. Is there a way without using HttpSession to persist the counter values? (It has not been taught to us, so we are not allowed to use it yet.)
For example, going back and having below input... First Operand: 4 Operator: + Second Operand: 5
...will result to... Addition: 1 Subtraction: 0 Multiplication: 1 (counter from previous computation maintained) Division: 0
I can insert data to table by using JSP Scriptlet easily but I have a hard time with servlet.
public class UsertToDatabase() { public boolean inserUser(String name, String email, String pwd) throws SQLException { PreparedStatement pstmt = null; boolean flag = false; System.out.println("start"); openConn(); System.out.println("start_1"); if(conn == null) {
[code]....
I am positive that the above code function fine. The problem is whenever I call UserToDB() class inside the servlet, and I got this error: java.lang.ClassNotFoundException: org.postgresql.
Driver which mean that my conn (connection) is not connected to the database but I have ensure to do so by calling openConn() before start the transaction.
Now I want to store those username and age(in .html) somewhere and I want those information in welcome.jsp. Now, I'm storing all those in session itself(In doGet method(servlet)).
2 Doubt) Also, when I get the session in servlet HttpSession session = request.getSession(); line No. 27. The session value is org. apache. catalina. session. StandardSessionFacade@69a8bf4f...I'm expecting that session is to be empty. Because, I dint store anything until that line.
I am trying to use hidden variable in project.When I launch my project i am able to get the welcome page.But when submit login values i am getting HTTP 404 error- Resource not found error.
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?
What is better and easier approach for exchanging data (in my case list of objects) between servlets in different nodes in same cluster? I thought about RMI or just direct url servlet call. But it seems that I'm missing something here.
My problem is the following:
I have to create some kind of diagnostic storage for each cluster member. It will collect all information and errors during application work.
And If I need to check application status I do web request and it will show me that these servers (cluster members) are okay and that node has an issue.
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 dynamic web project has a java class that captures a session variable with the following code.
HttpSession LoginSession = request.getSession(); String VAR = LoginSession.getAttribute("myVar").toString(); //This is the row 127
If i test the app in local (Mac + Java 1.8 + Tomcat 8) all works. In my remote cloud server (Ubuntu 14.10 + Java 1.8 + Tomcat 8) all works, except this class, that has this code. I copy the complete error here. Note that the row 127 of the error message is the second row of the previous code; and, if i comment this row with // and assign a fix variable all works. So, the problem is that 127^ row.
14-Dec-2014 08:15:23.923 SEVERE [http-nio-8080-exec-14] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [srvNavigation.SrvPT] in context with path [/myapp] threw exception java.lang.NullPointerException at srvNavigation.SrvPT.doGet(SrvPT.java:127) at javax.servlet.http.HttpServlet.service(HttpServlet.java:618) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
I am stuck with my application. I have jsp, servlet application with jasper report server. When I run the application through eclipse, everything works perfectly. But When I try to run it in Tomcat (without eclipse) it gives me the "Unable to resolve the class file " error. I tried all the solutions I got through the google, but still I am unable to come over it.
I m new to programming and am working on the college project. I have MySQL 5.6.20, Eclipse Kepler and Apache Tomcat 7.0.54. I m trying to retrieve the whole table from MySQL schema into a jsp. All the possible things i can do, i have already tried, but none of them are working.
The following attachment contains the whole project. I have my sql connection code in Sample.java file, which i want to get working in Fetch.jsp on the Submit button click. But it shows the tomcat error as localhost:8080/Sample HTTP Status 404-/Sample ; type Status report; message /Sample; Description The requested resource is not available.
<%@ 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">
Is it possible to get the list/ values in html/jsp from servlet?
I have a table inside an html/jsp page and when the user clicks a button I need to refresh the whole page with some additional text message.
Currently what I am doing is that I am using a java bean for the jsp page that contains a list of values inside the table then store it in session but I think there is a better way without storing it in session.
I tried using request.getParameter() but it only returns string.
i am newbie to servlet and m working on a project like online shopping. I have list of data items in my database and i am able to fetch and display the data from database but i want to know that how can i store these data items in ServletContext so that i can use use it frequently in other pages.