I have multiple classes in one package and was wondering how to I use one class while in another?
What I mean is I have one sheet with a class and another sheet with another class. (Separate tabs in Eclipse).
I'm having problems with this I've code like:
Java Code:
Public Class{
Objects
Constructor(){}
ActionListener Method(){}
Main Function()}
[Code]....
but I cannot declare variables in this method, how can I do this what can be the simplest method?
In addition: I've a marksheet class, a calculator class, & in main class I've 2 buttons one for marksheet & one for calculator, how can I make it so that if user clicks on marksheet button that class should be called & so?
My working directory is e:ajava. in package p1 i create two classes c1 and c2. net beans creates three files e:ajavap1srcp1, e:ajavap1srcc1, e:ajavap1srcc2. package runs without a hitch. i create another package p2 under e:ajava. i want to use class c1 in p2. pray what on earth should be my import statement in the p2 source code after the first statement 'package p2'. another related querry what should i include in my class path so as to gain access to c1 and c2 in source code of p2.
View Replies View RelatedI have a folder of classes that I am packaging together. Some classes are being packaged and compiling just fine. My other classes in the same package, however, are saying that they cannot find these classes.
View Replies View Relatedpackage demoServlet4;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ListenerTest extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
[Code] ....
Above is the code for three classes. class Dog compiles fine but other two classes cannot find Dog.
Following is the classpath and the JAVA_HOME
classpath = .;C:Program FilesApache Software FoundationTomcat 8.0libservlet-api.jar;C:Program FilesApache Software FoundationTomcat 8.0libjsp-api.jar
JAVA_HOME= C:Program FilesJavajdk1.8.0_25bin;
I am using javac -d WEB-INFclasses WEB-INFclassesdemoServlet4ListenerTest.java and javac -d WEB-INFclasses WEB-INFclassesdemoServlet4MyServletContextListener.java to compile the classes.
Is there any command to find all the classes inside a package?
E.g. : To find all the properties and methods inside a class String we use "javap java.lang.String" ....
I'm very new to Java, and I am creating a program that takes multiple user input to create one face. I have a class for the eyes, nose, lips, and headshape. For some reason, my program is not drawing the graphics. ***for question purposes, I have only included my head shape class and my test class****
my "test" class:
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class FaceTest
{
public static void main(String[] args)
{
String head = JOptionPane.showInputDialog("Would you like a circle, square, rectangle shaped head?: ");
[Code] ....
I have to make a retail item class that has description, price and quantity. I then have to make a CashRegister class that calculates subtotal, tax, total and displays it (toString). I also have to make a driver class to call the methods from main. I have no clue what I am doing and what I have done does not work. I am trying to make it sort of like a cart, in the CashRegister it should ask the user to enter the description, quantity purchased and the price. Then it would send that to the arraylist of retailitem. I am having trouble using those items in my other methods and then do not know how to call those in the driver class.. So here are my classes:
public class RetailItem {
private String description;
private int quantity;
private double price;
public RetailItem(){
description = "";
quantity = 0;
[Code] ....
I was trying to play around a little bit after learning creating multiple classes and stuff.However,i encountered a strange problem with reading a value from the user and then storing it in a variable.The usual way i do it is
Scanner variableName=new Scanner(System.in);
System.out.println(variableName.nextLine());
But when i trying to print the contents of the variable "variableName" the compiler throws a lot of errors .I am attaching how i have tried that out in my code
import java.util.Scanner;
class laptop{
private String modelNumber;
private boolean hasFan;
private float ramSpeed;
protected int numCores;
//private String input;
[code]....
Without the setInfo() in the laptop class the program functions as desired but i intend to ask the user if he wants to modify something and then reflect the same.
I have recently start learning about objects and classes in java. I understand that in order to use multiple classes in one file you need one class to be public and the rest are private. But after that I don't understand how to invoke the private class in the public class. I thought if I tried programming on my own I can have a better understanding of it, but had no success.
View Replies View RelatedAlright.. So I have to make a retail item class that has description, price and quantity. I then have to make a CashRegister class that calculates subtotal, tax, total and displays it (toString). I also have to make a driver class to call the methods from main. I have no clue what I am doing and what I have done does not work. I am trying to make it sort of like a cart, in the CashRegister it should ask the user to enter the description, quantity purchased and the price. Then it would send that to the arraylist of retailitem. I am having trouble using those items in my other methods and then do not know how to call those in the driver class...
So here are my classes: [URL] ....
I have multiple Java classes that holds lots of time based parameters, e.g.: (simplified):
Java Code: class Engine {
float rpm;
boolean enabled;
int runningTime;
[code]....
Is there any simply solution to map all these parameters from my TimeRecord to one list(vector,map) of params that user can choose from and see the value in proper form (floating type, boolean type) ?
I just want that user can pick a paremter's name from list or combobox and choose parameter that he wants to see. I don't want to duplicate the data - just some kind of mapping algorithm between list of parameters names and my TimeRecord. eg. some collection class that holds all names and connections: Parameters params; fill combo/list from this class for ( String name : params ) { combo.add(name);}, then when user picks some field from combo: params.getValue( myTimeRecord, name ) return correct parameter value (just my first thought)
Later, I want to replace all floats,ints,booleans with some kind of templated class eg. Value which will hold all kinds of measurement unit with conversion support - but it's only a plan now.
I was reading the book, "Head First Java" and it was talking about how there may be multiple classes in a large application, but there will be only one main method.how does it work that way? How can you have multiple classes, but only one main method?
View Replies View RelatedI'm trying to create a Java swing chess application, but would like to divide the GUI part of it into at least two different classes (possibly more later, but I'm not sure yet). Currently I have a mainGUI class and a ChessBoard class, both of which extend JFrame. I want the main GUI class to contain a JPanel which will house several components, including a JPanel originating from the chessboard class that contains the actual board.
Is there any way to do this? I tried just creating a ChessBoard object in my main GUI class and then adding it to the component, but I got an illegal argument exception, because apparently you can't add one JFrame to another. How to do what I'm trying to do, or just how to split GUIs into multiple classes in general?
I studied that java does not support multiple inheritance using classes. It is fine practically, but I have still a question in mind:Lets see the below code.
class Test{
------
------
}
class MyTest extends Test{
---------
---------
}
Here, as we know that that Object is Super class for every class in java. and I have already extends a Test class in MyTest.My question is: How is it possible to extend features of two class at the same time?
Theoretically,
MyTest extends Object &
MyTest extends Test.
Let's say hypothetically you're making a huge program and use a lot of imports (ex import java.util). If you only need a few specific things from java.util, will it use more memory importing java.util.* compared to only importing lets say java.util.Scanner, java.util.ArrayList, etc. Basically does importing a whole package use more (if any at all) memory than only importing specific package parts?
View Replies View RelatedI know that Servlets are meant to do the JDBC tasks, JSP are only for displaying the final information forwarded by the Servlet.
JSP are Servlets too, but I heard an idea that it is safer to make database operations in a Servlet.
The idea is that I have a few JSP that use JSTL tags to retrieve some database information. By doing this I was concerned that this may be bad design, though I really wanted to get in fit with the JSTL tags.
Are there any security weaknesses if doing some JDBC stuff in a JSP, by using JSTL or plain Java code in <%...%>?
P.S. In my JSP I only retrieve data, not modifying it.
I've created a Dynamic Web Project in Eclipse Kepler EE, connected it to a Tomee plus 1.7.1 server and created a servlet and a POJO. So after opening the browser and trying to do something with the classes, the servlet worked as expected, but the POJO returns error 404.
The actual code is something like this:
// The servlet
public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("I'm a servlet.");
[Code] ......
So when I type "localhost:8080/<project_name>/MyServlet" I get the expected "I'm a servlet." message. The problem is with the POJO:
//The POJO
@Path("/MyPOJO")
public class MyPOJO {
@GET
public String get() throws IOExeption {
return "I'm a POJO.";
}
}
I have nothing about that class in the web.xml file. I have this class, that I don't really know what it does:
@ApplicationPath("/sth")
public class ApplicationConfig extends Application {
@Override
public Set<Class<?>> getClasses() {
return new HashSet<Class<?>>(Arrays.asList(MyPOJO.class));
}
}
Application is a class from M2_REPOjavaxws
sjavax.ws.rs-api2.0.1javax.ws.rs-api-2.0.1.jar
So when I enter "localhost:8080/<project_name>/sth/MyPOJO", I get error 404, no exceptions no logs. I've tried to debug but it doesn't hit any breakpoints.
Maybe it has something to do with the exception I get when I start the server:
Nov 19, 2014 6:44:50 PM org.apache.myfaces.ee6.MyFacesContainerInitializer onStartup
INFO: Added FacesServlet with mappings=[/faces/*, *.jsf, *.faces]
Nov 19, 2014 6:44:51 PM org.apache.myfaces.config.DefaultFacesConfigurationProvider getStandardFacesConfig
INFO: Reading standard config META-INF/standard-faces-config.xml
[code]....
I've tried to add the line that is missing in the server.xml file but then the server doesn't start at all.
When my college tries to run it on his PC, it work with both the POJO and the Servlet. We can't find any reason why it's not running on my PC.
May I know what it means when you say "What is the OOP mechanism is used to link the library and the swing framework?"
What are the examples of OOP mechanisms? Is there a website explaining this in detail?
Question 1: Upon importing the Play Framework content in Eclipse there's a default codes as localhost:9000 is immediately routed to play framework website controllers, checked and running fine test, checked and running fine conf, checked and running fine the problem is the views under app on all youtube tutorials and other websites, the contents of views is editable but when my brother tried to, he cant edit it
Question 2: Is there an easy tutorial on POST, PUT, GET, and DELETE for eclipse-playframework
Question 3:my brother is using POSTMAN - RESTCLIENT to test his HTTP METHODS (post, put, get, and delete)and is there a tutorial where they also test the HTTP METHODS using POSTMAN?
I am new to Java Stored Procedures. There is a PL/SQL package in our legacy application(Oracle 9i) which pulls data from Oracle 8i source database through a DB link. Now we have upgraded our databas to Oracle 11g R2 from 9i. So the DB lint to Oracle 8i will no longer work in 11g. Hence I have created a Java stored procedure that establishes JDBC thin connection to the source 8i database. I have loaded the java stored procedure in the database using loadjava and have created a call specifaction.
I have called this java stored procedure inside the PL/SQL package. Now while executing the PL/SQL package, it takes the default driver ojdbc6.jar to establish JDBC connection and fails to connect to the 8i database giving ArrayIndexOutOfBounds Exception. While running the code in the linux application server with classes12.jar the code succeeds. But when the same is called in the database it fails.
1. How can I make my PL/SQL call use classes12.jar while calling the Java Stored Procedure?
2. How can I load the jar file(which includes my classes and the classes12.jar) into the datase as one object? (When I tried to load the whole jar, in database the classes and dependent jar loaded separately)
3. Is there a way to use classpath while calling the Java Stored Procedure like how we do from Unix?
I am trying to connect to Sql Server database using Oracle UCP with sqljdbc4-3.0 JDBC driver for Sql Server,with different ports and instances.
– the issue is with the port being ignored in the server string.
For example, using port 1440 connects to the default instance (which is on port 1433) rather than MSSQLINSTANCE1 which is on 1440.
Below are Server hosts used.
sql005.sqlasoftware.com (connects correctly to the default instance)
sql005.sqlasoftware.com:1440 (connects incorrectly to the default instance on port 1433)
sql005.sqlasoftware.comMSSQLINSTANCE1 (connects correctly to the named instance)
.
.
.
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/MyServletPDF?username=TEST");
response.setContentType("application/pdf");
dispatcher.include(request,response);
%>
While debugging everything is going through... even it passes through the last line. But the pdf is not launching... showing only a blank screen in its status bar as "Connecting"... Earlier it was launching.. but suddenly this issue is raising up. Is there any IE settings need to be checked?
I get the following error when trying to run code.
java.lang.NullPointerException
at conntecttoDB8.SSHCommandExecutor.main(SSHCommandEx ecutor.java:26)
package conntecttoDB8;
import java.io.InputStream;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
[Code] ....
We currently have an application which uses JDBC to connect to the backend database (DB version - 11.2.0.3 ). The application uses a properties file in which the password for the db schema is hardcoded in plain text format. Due to security restrictions we have been asked to make sure the password is encrypted in the file and no direct access is made to the schema using the plain text password. Best options we can use to make this password encrypted both at Oracle DB side and Java side.
View Replies View RelatedI have developed a code to connecting remote windows M/C from local M/C by using SSH2 (ganymed-ssh2-build209.jar) API. when I run the code its giving below error. Is there any other way to connect remote windows system using java code.
Exception.
java.io.IOException: There was a problem while talking to <host name>:22
at ch.ethz.ssh2.Connection.connect(Connection.java:642)
at ch.ethz.ssh2.Connection.connect(Connection.java:460)
at Connect.RemoteServer.ConnectWindowsServer.runCommand(ConnectWindowsServer.java:55)
at Connect.RemoteServer.ConnectWindowsServer.main(ConnectWindowsServer.java:27)
Caused by: java.net.ConnectException: Connection refused: connect
[Code] ....
JAVA Code
import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
public void setAuthenticationInfo(String hostname, String username,String password) {
this.host = hostname;
this.userid = username;
this.password = password;
this.recentCommand = "";
System.out.println("setting authentication info completed for host=" + host );
[Code] .....