I implemented the new DB, I have changed all the variables accordingly. When I execute the website, I get errors and it keeps referring to the old db.
Using sql langauge, the website has been implemented in Java.
I am trying to make a for loop using an iterator that refers to an object of a class that hasnt been made yet. The class is called MyArrayList but it does not have a Main. A MyArrayList object is made externally so I am unsure how to refer it to the object from within the class. Is there a place holder I could use such as Object.Iterator() or something similar. I have created an inner class that implements the Iterator interface. Here is the code that I need to adjust to do this:
public class ListIterator<E> implements Iterator<E> {
public myIterator() {
Iterator it = MyArrayList.iterator();
while (it.hasNext()) {
System.out.println(it.next());
}
}
}
If a method is overridden but you use a polymorphic (supertype) reference to refer to the subtype object with the overriding method, the compiler assumes you're calling the supertype version of the method.
is this true? maybe i'm misunderstanding it, but i thought the JVM looks at the object at run time and checks the object type. the context of the quote is about checked exceptions, but it seems like the statement should stand regardless of context. but this doesn't back up my experience. for example:
public class Test{
public void print(){
System.out.println("Super");
} public static void main(String[] args){
Test t = new SubTest();
[Code] ....
Will invoke the subclass method. like i said, maybe i'm missing something.
I want to set the values coming from database with multiple field's Through AJAX and Custom XML. How to do ???
View Replies View Relatedi am stucked with a little error in servlets
this is my jsp page
form.jsp
<form action="InsertData" method="post" >
username:<input type="text" name="username">
Password :<input type="password" name="password">
[Code]....
i am getting wroor page not foung 404
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;
[Code] .....
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:
public Connection connect() {
try {
return DriverManager.getConnection(url, user, pass);
} catch (SQLException ex) {
return null;
}
}
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 am trying to insert data using servlet but it is not getting into database.
I have a two JSP's form from which i enter the data and using servelt trying to insert the data into database.
JSP page code:
1.add_question_list.jsp
<script language="JavaScript">
function validate(form) {
if (form.question.value == "") {
[code]...
How can we insert data through java servlet?
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.
This is my servlet code:
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String email = request.getParameter("email");
String password = request.getParameter("password");
List<String> errList = new ArrayList<String>();
[code]....
here is the code,
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?
How we can get the list of records from database my sql using jsp pages and servlets so that it show results on webpage.
View Replies View RelatedI am trying to display a list fetched from DB in a JSP.
My servlet mapping is:
<servlet>
<description></description>
<display-name>DocumentsServlet</display-name>
<servlet-name>DocumentsServlet</servlet-name>
<servlet-class>com.xyz.servlet.DocumentsServlet</servlet-class>
[Code] ...
The code in the servlet is:
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List<Doc> docs = null;
Connection con = null;
[Code] ....
The code in JSP is:
<%
List<WWDoc> completedDocsList = (List)request.getAttribute("completedDocs");
System.out.println("In JSP == "+completedDocsList.size());
%>
The request is not coming back to the JSP page.
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".
1) I will have to create two columns in MYSQL database and insert data in that, each column contain 8-9 k data.
2) Then i need to plot this data in chosen GUI in three separate plots on one screen as shown in attached image.
3) Time interval for X-axis for plotting individual graph is 0.001.
4) Then i need to plot these two waveform data against each other as XY graph as shown in graph.
How to do this or what language and technique i need to choose.
I am trying to output data but get empty table. What am I doing wrong? Here is my code:
Class Item:
package com.store.util;
public class Item {
private Long id;
private String name;
private String description;
private String category;
private Double price;
[Code]...
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?
My query retrieves more than 5000 records from Oracle database. I want to display the records 100 per page. I know it is called pagination. Any detailed styp-by-guide or tutorial or example available?
View Replies View Relatedi 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.
View Replies View RelatedI am trying to display rows from my database from servlet by passing it to a JSP, but nothing is displayed. I checked the syntax and even the source of the page shows that it gets the data but the rows are not displayed!
My servlet (serv.jsp)
package Pack1;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
[Code]....
My JSP (SP.jsp)
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Search Page</title>
</head>
<body>
<h1>TITLE</h1>
[Code]....
My servlet file is in the Pack1 package under Source Packages and jsp file is under Web Pages.
I have a HTML table whose rows are getting generated through javascript function. I want to save this data in the table rows.
**HTML Code**
<div style="width:100%;height:100%;border:1px solid black; overflow-x:scroll; overflow-y:scroll; padding:0">
<table border=0>
<tr>
<td>
<input type="button" name="add_details" id="add_details" value="Add" onclick="AddDetails()">
<input type="button" name="delete_details" id="delete_details" value="Delete" onclick="DeleteDetails()">
[Code] .....
When i press submit button in my form of JSP, how can i access table data?
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">
[Code] ....
So, there's a new requirement to log which user issues what database operations. The dumb way is to pass the session object around, but I hope said dumb way is not the only way to achieve this. Hopefully there's another cleaner and smarter way to do this.
View Replies View RelatedI want to retrieve the data from this table given below and insert that data in the database in the next servlet
package com.sk;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
[Code] .....
why my program doesn't work. Here's the code :
public test5 {
public boolean test(int grille[][]){
for (int i = 0 || i < grille.length || i++){
int max = grille[i][0];
for (int e = 1 || e < grille[i].length || j++){
if (grille[i][e]== max && max !=0){
solution = false;
System.exit(1);
[code]....
I get quite a few errors while trying to compile the BeerSong from the Head First Java book. I copied the text from another person that did the beer song on this forum and it worked as expected. What I can't figure out is why mine is not working when it looks like the text is exactly the same between the two versions. His works, but mine doesn't.
Here is the text and errors that I get:
public class BeerSong
{
public static void main (String[] args)
{
int beerNum = 99;
String word = "bottles";
[code]...
It's probably really obvious, like it usually is, but I can't figure out why I am getting these errors on multiple functions.
if (!client.lowMem) {
for (int l = this.onDemandFetcher.getVersionCount(2), i2 = 1; i2 < l; ++i2) {
if (this.onDemandFetcher.method569(i2)) {
this.onDemandFetcher.method563(1, 2, i2); //Error
[Code] ....
The error I get on this line of code is 'Custom may not have been initialized', but no matter what I do, the error sticks.
Custom.cacheIndex = (Custom.cacheIndex + 1) % 10;
final Custom Custom = Custom.cache[Custom.cacheIndex];
//^^^^^
I am making a simple mod/hack for a game programmed in Java. I located the .class file I needed and deobfuscated it and then decompiled it. After that I went in and made a very simple adjustment that I wanted to make. Unfortunately I can across a problem when trying to compile the file! The file won't compile because there are errors. The reason there are errors is because this is just one file out of an entire game. I know this my seem weird, but is there some way I can compile the file with the errors.
View Replies View Related