I have an int array that has information read from a file. Now i want to display this int on a jtable but ofcourse i cant display primitive data types.. and also you cannot cast an int[] to an Object[], so I am stuck...
View RepliesTrying to find a way to use primitive data types to overload sound()method. I can't seem to warp my head around using an int or a double to overload the method. And if I did, how do you call them in the main afterwards?
View Replies View RelatedHow I'm supposed to write out the statement.
I am fairly certain that I should be making variable "b" and "c" a float. But beyond that I'm confused.
uploadfromtaptalk1407333378833.jpg
I get an error when I try to divide 500 miles by 25.5 gallons
Exception in thread "main" java.lang.NumberFormatException: For input string: "25.5"
at java.lang.NumberFormatException.forInputString(Num berFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at Mileage.main(Mileage.java:42)
Java Result: 1
[Code] .....
I need to write a simple program that displays up to 5 pairings of data types (int, string) (string, long) ect. I need to have at least two classes, a Pair class (generic) and an PairTest class.
View Replies View RelatedWhy the following is happening.
For the below code, when I execute it, it prints
Short method 10 //result 1
Sub class short method 10 //result 2
Which is as expected but if I comment out line 3, then it prints
Integer method 10 //result 3
Integer method 10 //result 4
I can understand result 3 is because of an upcast from short to int, since FunWithOverloading will not have a overloaded method with short now. However, what is happening with result 4? Shouldn't it call methodA of the subclass with the argument type short? If its because I have declared the reference variable, derived, of the type FunWithOverloading, then how come the first result correctly picks the overloaded method of the sub class?
class FunWithOverloading{
void methodA(int x){System.out.println("Integer method " + x);}
void methodA(short x){System.out.println("Short method " + x);} //line 3
} class OverloadedSubClass extends FunWithOverloading{
void methodA(short x){System.out.println("Sub class short method " + x);}
[Code] ....
I've got a question to ask.
public class AutoBoxingExample {
public void add(Integer intVal){
System.out.println("Wrapper");
}
public void add(int value){
System.out.println("Primitive");
}
public static void main(String[] args) {
AutoBoxingExample auto = new AutoBoxingExample();
auto.add(12);
}
}
The output is "Wrapper". What would be the reason behind it?
Why is it necessary to implement the comparable interface for primitive types and not for classes such as Integer, String etc . . . ?
View Replies View RelatedI was trying to run an sql query to display onto my jtable. However, i got this as a result:
oracle.sql.CLOB@11876a2
When I run the same SQL query on Toad i get the field hugeclob and one is then able to see whats inside the field. I want to basically either have a hugeclob on my jtable or perhaps to display on a textarea the data
I am totally new to Java. What is the purpose of this method?
Flow of the int x=3; like where does the 3 go step by step?
Passing Primitive Data Type Arguments (from oracle java tutorials)
Primitive arguments, such as an int or a double, are passed into methods by value. This means that any changes to the values of the parameters exist only within the scope of the method. When the method returns, the parameters are gone and any changes to them are lost. Here is an example:
public class PassPrimitiveByValue {
public static void main(String[] args) {
int x = 3;
// invoke passMethod() with
// x as argument
passMethod(x);
[Code] ....
I have doubt in generics,
List<int> c=new ArrayList<int>();
why we cannot use primitive data type like int,double.
I have a code in which I am reading input from System.in and Destination is some where else
Here is my code
File file=new File("D:/output.txt");
OutputStream os=new java.io.FileOutputStream(file);
Scanner scanner=new Scanner(System.in);
System.out.println("Enter Data to write on File");
String text=scanner.nextLine();
int c=Integer.parseInt(text);
int a;
while((a=c.read())!=-1)
os.write(a);
System.out.println("File Written is Successful");
In the line while((a=c.read())!=-1)
a compile time error is shown "cannot invoke read on primitive data type int"
Where I am going wrong?
I have declared an array list that will store data type of 1 Character and 2 integer. The data that will be store in this list is
1. A = {0 3}
2. B = {0 5}
3. C = {0 3}
4. D = {0 3}
5. E = {0 5}
6. F = {0 6}
Now here the alphabets are routers and integers are there con1 and con2 respectively. I have a set of router={ A,B,C,D,E,F}.
Step 1:I have to subtract con1 from con2 i.e. (3-0) of all the routers and
Step 2: then put the router having largest value in new set 1 and
Step 3: then this router will be subtract from the router set.
Step 4:then again I have to repeat the step 1 until the value of routers become <= 1.
Now what I did is I defined 3 arrays first is String array that stores names of routers, 2nd array that stores the first value and 3rd array that stores the second value. I can find the largest value but how to store the name of router against the largest value in the set.
I have to read data from a text file and print it in a new text file. An example of one line is like this:
Johnson 85 98 75 89 82
I then have to take the average of all the numbers and assign a "grade" to the numbers for each line of the text file and make a new file so it looks like this for 10 lines:
Name 1 2 3 4 5 Average Grade
Johnson 85 98 75 89 82 85.80 B
My problem is extracting the data from the file so I can use it.
I have seen many ways of describing what objects are, one being that objects are a user-defined datatype. However, if objects are datatypes, then what does that make classes? To me, it seems as though classes should be the "types" of data defined by the programmer, and objects should be the specific "values" of that user defined data type. As an example, an integer would be a class, while 1 would be a "value" of that class, i.e. an object. From this point of view, I don't see why a specific number would be a data type... Therefore, why do we say that objects are user defined data types rather than classes?
View Replies View RelatedI would like to create an ArrayList from data types stored in a text file.The ArrayList would be multidimensional with two data types; int, String.
Example text file could be:
4 cahiers grand format
3 stylots bic bleu
5 gommes
I find it very difficult for multiple data types i don't see how its possible.
I am trying to remove the duplicate elements from ArrayList using .contains() if elements are primitive datatype it works but user-defined datatype does not work.
public class UserBean {
String name;
String address;
public String getName() {
return name;
[code]....
I am creating a calculator in which a user will directly input the numbers and the operator...
Here is my code:
int answer = 0;
int num1, num2;
char operator;
System.out.print("Enter calculation: ");
num1 = kb.nextInt();
operator = kb.next().charAt(0);
num2 = kb.nextInt();
The code above will accept the user input when there are spaces like this: 1 + 1
So the program will give an answer which is 2...BUT
if i input 1+1 it will give an error...Exception in thread "main" java.util.InputMismatchException
How can i do that it will separate integer to character? because i set the operator as character....
So that it will accept one digit to several digit numbers... like 500+84 or 1520+872??
I have created a JTable which does not display. When I run the program I can see that a line appears around the edge of the panel indicating the JScrollPane is added to MyJPanel, however, the table is missing. This is the table
public class MyJTable extends JTable {
private Object[][] data;
private Object[] columns;
private MyTableModel model = new MyTableModel(data, columns);
public MyJTable(Object[] columns, ArrayList<Data> data) {
this.columns = columns;
for(Data d:data){
[code] ....
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class DisplayFinal_Panel extends JPanel {
private JLabel label1, label2, label3;
private JTextField box;
[code]....
I only want Listener 1 to work right now. Also, user input is in TextField.
I want to display a Hash Map to a GUI..my hashmap contains data as follows:
BC111S04=[22, 17302, 50, 17485], BC111S03=[22, 17302, 50, 17485], BC111S02=[22, 17302, 50, 17485], BC111S01=[22, 17302, 50, 17485], BC111SV1=[22, 17302, 50, 17485], BC111SV2=[22, 17302, 50, 17485], BC111M01=[22, 17302, 50, 17485]
in above BCXXXXXX is the Url of DB and the ones in Square bracket are results of some query.I want to display them in format as in below picture:my code for GUI is as follows
package gui;
/**
* Class that takes a query as input from GUI and fetches the required output from Database and display it on GUI.
*/
import java.sql.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import com.POS;
[code]....
HTML Code:
import java.util.Scanner;
public class BellmanFord {
private int distances[];
private int numberofvertices;
public static final int MAX_VALUE = 999;
[Code] ....
I am trying to display two types of table one with initial cost and another one with new cost. Based on the java code here i already have one table but don't know how to display another table.
Attached is the sample output that i am aiming for. The output table for the above code is:
Enter the number of vertices
6
Enter the adjacency matrix
0 4 0 0 -1 0
0 0 -1 0 -2 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 -5 0 3
0 0 0 0 0 0
Enter the source vertex
1
distance of source 1 to 1 is 0
distance of source 1 to 2 is 4
distance of source 1 to 3 is 3
distance of source 1 to 4 is -6
distance of source 1 to 5 is -1
distance of source 1 to 6 is 2
I'm trying to display the data from database in a jtable by following the jtable demo example in Java Tutorials Sample Code; but, I couldn't output the data to the jtable. The following code is what I've done so far.
import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;
public class Patient { static String szJdbcURL = "jdbc:oracle:thin:@129.78.110.188:1521:MyDB";
static String szUser = "...";
static String szPasswd = "...";
static String szModelName = "...";
[Code] .....
I am trying to get the data entered in a JTextField into a JTable but not clear on how. The LeftPanel is where the button is located and the RightPanel is where the JTable is. I want the actionPerformed to update the row of the JTable but I can't figure out how. There is another class that controls the GUI but did not think it was necessary to include. Also, I am aware that I am getting an error at the addRow line, can't seem to alleviate it.
public class LeftPanel extends JPanel {
private static final long serialVersionUID = -2311952438693382407L;
private RightPanel rPanel;
public LeftPanel(){
Dimension size = getPreferredSize();
size.width = 250;
setPreferredSize(size);
[code]....
I have been trying to learn a bit about JTables for a project I want to undertake. I have created a new JFrame in netbeans and added a button. Onclicking the button I want add some data to a JTable model and then output the JTable with the data. When I click the button again I want the same process to happen again and overwrite the previous table being displayed.
I have written the following code below:
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
[code].....
The problem I have is that when I click the button for a second time the table stays on the screen exactly as it did following the first click. I can see that the data in the model is changing so I am not sure why a new JTable is not drawn.
I am developing a quotation generator application using Java. I am using a JTable to capture user input(this input is taken from a database i.e. each cell of the tale will have a combobox where the user can select an input value). when the user is done he/she has to print the quotation as A4 page.
My issue is: Is there a way of doing it besides using the JTable?