If I change the servlet and have "request.getRequestDispatcher("/pages/ViewCompletedWWDocs.jsp").forward(request, response);" un commented, I get exception "java.lang.IllegalStateException: Cannot forward a response that is already committed".
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.
The program contains username and password which on submission checks with the database if the details entered are right or wrong....on right details it Displays Welcome (name) and (lastname) parameters from database.
I am very new to multithreading thus the code below reeks of ignorance,but i guess thats a place to start from.I am trying to obtain values that are already in my db and send them to a database by creating a new thread as follows:
//ADDED JUL 15 2014 12:07, LISTITEMS SO public void getList() throws SQLException { String sql = "select * from PRODUCTS"; out.print(m_Stmt); ResultSet rs = m_Stmt.executeQuery(sql); ExecutorService es=Executors.newCachedThreadPool(); es.execute(new Runnable(){ @Override
package signup; /* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates
I have two programs that I'll post below, one is a Server and the other is a Client. The ChatServer runs once and many clients can run ChatClient from separate computers and talk together in their GUI's. The the client program comes with two buttons, one that's simulates the sending of a message to a single user ; "Send Message To User", and one that just generally sends a message ; "Send Message To All". Although now the Clients on the server seem to be able to selectively send messages to an individual by giving the recipient name, all the clients can see that message, which is not exact what I am aiming for. What I am going for is having the "Send Message To User" button click to send a message to the named user without all other users seeing the message.
Now I have tried thing like having various input output streams and trying to connect those, but no luck. Tried fiddling with having the names arraylist directing the messages to one client versus all but that did not work out either. How I what I would need to do to go about doing this?
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 want to retrieve file from database which is stored with blob datatype and i am passing manually id associated with in code. Its not retrieving the file.
public class retrieve_image extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ResultSet rs = null;
I am trying to make a simple login using netbeans, derby database included in netbeans and tomcat server. I made everything nice and separated: I have a model package with a class called DbConnector that has the following method:
Then i have another class, an userDAODB that has a password check method:
public boolean checkPassword(String user, String password) { try (Connection con = new DbConnector().connect(); Statement stmt = con.createStatement()) { //checks the password in the database
In the main method of this class i tested everything, it works very nice, logs me in, other methods work too, no problem what so ever.But then i go to my servlet:
public class LoginTest extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { String username = request.getParameter("username"); String pass = request.getParameter("pass"); UserDAODB userDAO = new UserDAODB(); boolean authe = userDAO.checkPassword(username, pass);
[code]....
So when i start the webpage and i try to click on the login button I get a NullPointerException com.model. UserDAODB. check Password (User DAODB. java:14) - so line 2 here
I have been googling a bit, i placed the derby.jar and the derbyclient.jar in the lib directory of tomcat, i tried to modify the context.xml of my application, but then it wouldn't even start anymore.
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.
ResultSet rs = result.executeQuery(selectsql); int columns = rs.getRow(); while(rs.next()){
[Code].....
I can print out the result correctly, there are three rows of result from the database, but they are shown in one row on the browser, how could i show the result one row after another to let it looks pretty?
I'am new to java, this question may have been asked earlier but I'm not getting the exact answer.I want to add data from database into at and display it through jsp. But empty or null values is shown i.e no data is being displayed and when I execute the same sql query which is used in code in sql server then required output is displayed. My java code is:
Java Code:
public List < Alarm_Bean > get_Count(String system_Name) { if (system_Name.equals("MPS")) { try { con = getConnection(); stmt = con.createStatement();
I need to implement an editable JComboBox. It should display a list of rivers from a database. However since the number of rivers is very large, the entries must be dynamically filled after the user has typed in three or more letters.
I have tried to solve this using a KeyAdapter. Everythings works. However after the user has typed in three characters, these three characters are selected in the Combobox. Of course when the user continues to type these chars will be replaced. I have so far not found a solution to deselect the characters and place the cursor at the end.
this.fliessgewaesserComboBox = new JComboBox<UisFliessgewaesser>(); this.fliessgewaesserComboBox.setEditable(true); this.add(this.fliessgewaesserComboBox, c); FliessgewaesserSuchenKeyAdapter fliessgewaesserSuchenKeyAdapter = new FliessgewaesserSuchenKeyAdapter(this); this.fliessgewaesserComboBox.getEditor().getEditorComponent().addKeyListener(fliessgewaesserSuchenKeyAdapter);
I'm working on a consulting training project to create a eCommerce online shopping application. Nothing big, just something functional and simple. That's why I want to structure it with the easiest maintainability possible. I've already ironed out the the database entities and how they'll relate to one another and even managed to establish connection to the database from my java application class. NOW I need to configure a user session on the web.xml, from what I've learned so far in my consulting, I can easily use jsp and servlets to have httpsession objects receive and send the information needed to and from the database, but the question is, how many do I need for a client's session?
Would maintainability be easier if I divide each entity's class actions to different servlets(a customer servlet, order servlet, product servlet, etc...), or can a single servlet handle an entire session without any complication?
