I am trying to read contents from a file and display them to the user. However, when I enter the file into the program I get the following error: "exception in thread 'main' java.util.MismatchException. What am i doing wrong?
import java.util.Scanner;
import java.io.*;
public class Project1{
public static void main(String[] args) throws FileNotFoundException {
double balance;
double item1Price;
[code]....
import java.util.*;
public class CalculatorProjectVincent {
public static void main(String[] args) {
System.out.println("Welcome to this incredibly uneeded and redundant calculator program!");
breaker();
Scanner kb = new Scanner(System.in);
System.out.print("Enter an expression or EXIT to end the program. > ");
[Code] ....
When I run the program and input "v 100", it gives me the following:
----jGRASP exec: java CalculatorProjectVincent
Welcome to this incredibly uneeded and redundant calculator program!
- - - - - - - - - -
Enter an expression or EXIT to end the program. > v 100
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
[Code] ............
I have written the following code to calculate tax payments based on income and filing status :
import java.util.Scanner;
public class computeTax {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// prompt for filing status
System.out.println("enter '0' for single filer,");
[Code] ....
The while loop initiated on line 21 is there so that in case the wrong input is given at the prompt given in line 24, the program outputs "please type the right answer" with the command on line 254 before looping back to line 24 and prompting the user to enter his status number. The program works as long as the input at line 28 is an integer. Not surprisingly if the erroneous input here is not an integer, the program outputs the following error message :
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at computeTax.main(computeTax.java:28
To try to solve this I used the Try / Catch technique with the following version of the code :
import java.util.Scanner;
public class computeTax {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// prompt for filing status
System.out.println("enter '0' for single filer,");
[Code] ....
I am trying my code which catches exception when mismatch variable is inputed as i read it with Scanner. It seems right for me but whenever i run it, it keeps leaking memory or something like that
Code :
import java.util.*;
public class Exercise10_1 {
static Scanner scanner = new Scanner(System.in);
public static void main(String[] args) {
boolean exception;
do
[Code] .....
My program is user input 20 char and the program will print the most common. So I use another int arr which count the number appears in the original array. i know its not so Effective but I don't know why it run but it stop in the middle. I got this code :
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 20
at Ex2.common(Ex2.java:39)
at Ex2.main(Ex2.java:23)
import java.util.Scanner;
class Ex2 {
public static void main(String[] arg) {
Scanner reader = new Scanner (System.in);
char[] arr=new char[20];
System.out.println("Please enter 20 chars:");
for (int i=0;i<20;i++)
[Code] ....
I've got a nasty nullpointer that I have tried to resolve to no avail as of yet. The program should prompt for a listings.txt file and take its info and write to a report file. Here's the stacktrace:
run:
Input file: listings
Exception in thread "main" java.lang.NullPointerException
at java.io.Writer.<init>(Writer.java:88)
at java.io.PrintWriter.<init>(PrintWriter.java:113)
at java.io.PrintWriter.<init>(PrintWriter.java:100)
at kettask2b.PropertyListingsReport.main(PropertyListingsReport.java:34)
Java Result: 1
Some adjustments that I have attempted are:
BufferedWriter pwfo = null;
for (int i = 0; i < args.length; i++) {
String string = args[i];
pwfo = null;
[Code] ....
Here's the code:
package kettask2b;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
[Code] ....
I'm creating a program that will compile and run another java program:Lets say I have a program in directory
D:HelloWorldsrc
and compiled program will be in
D:HelloWorldin
inside src and bin is a folder hello (that's a package)
package hello;
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
System.out.println("Hello World");
}
}
This program will be run by another program (that's the program that I am creating).Here is the code of my program:
package runnercompiler;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
public final class RunnerCompiler {
[code]....
I decided to code this quiz I took in class about asking the user to input a string and the code is suppose to check for upper case letters. If a upper case letter is found, it should increase a count by one. Once the check is done, it should display the number of uppercase letters. For some reason I am getting this weird compile error stating that symbols can't be found...
Java Code:
import java.util.*;
import java.lang.*;
public class StringCheck{
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("please enter a string: " );
String s = input.nextLine();
[Code] ......
I created Myproject folder. Inside I have 3 folders:
/lib
/src
/bin
Inside src there is a .java file:
public class hello_world{
public static void main(String[] args){
System.out.println("Hi, from hello_world");
seba.st.hello_world_package test1 = new seba.st.hello_world_package();
test1.packFunc();
}
}
inside lib is a packEx.jar file which I created from this .java file:
package seba.st;
public class hello_world_package{
public void packFunc(){
System.out.println("hi from pack_func!");
}
}
I am trying to run this program from terminal with this command
javac -d bin -sourcepath src -cp lib/packEx.jar src/hello_world.java
and I get this error:
src/hello_world.java:11: error: cannot find symbol
test1.packFunc();
^
symbol: method packFunc()
location: variable test1 of type hello_world_package
1 error
What am I doing wrong ? How can I compile and run this program from terminal?
i wrote this program:
class hellojava
{
public static void main(string[] args)
{
system.out.println("hello java");
}
}
Then i saved this file with name hellojava.java(notepad) in C drive in separate folder c:myjavaapp(not in c:java folder).
When I am compiling(with javac hellojava.java) it shows following error:
cannot find symbol public static void main(string[] args), and also says package system doesnot exists system.out.println("hello java");
I have installed software Net-bean 7.4 and it's working, Now i want to compile and run individual program through command line, I mean where i can find java & javac file under the netbean software, so i am able to do this.
View Replies View RelatedI am trying to compile multiple jar files into one jar file from inside a java program. I know how to do this with shell scripts but I would rather have a universal application than one that will only run on Mac, Windows, or Linux. This is my current compiler code:
if(System.getProperty() == "Mac OS X"){
Runtime.getRuntime().exec("javac -classpath jar1.jar; jar2.jar");
}
I would then continue this on for Linux and Windows, but this limits my application.
Here are the errors I am getting:
SlotMachine.java:21: error: illegal start of expression
public static void getNums(int [] slots)
^
SlotMachine.java:21: error: illegal start of expression
public static void getNums(int [] slots)
[code]....
i keep fixing small things and cannot get it to compile. Below is the original code,
import java.util.Scanner;
import java.util.Random;
public class SlotMachine
{
public static void main (String args[]) {
int userMoney;
Scanner input = new Scanner(System.in);
System.out.print("How much money to start with?
[code]....
The first 4 class below are the main classes while the last class is the testing class. I got it all to compile but for whatever reason there are several runtime errors. I have spent hours trying to figure out what they are, but I was only able to eliminate a few.
import java.util.*;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Set;
import java.lang.*;
public class PhoneNetwork {
[Code] .....
Netbeans do not detect any syntax errors, but I when I check the build it retuned areas they were a few; It's a simple program name 5 people, gade them then do final calulatoins it's called "grade tool.
heres the code
package gradingapplication;
import java.util.Scanner;
public class GradingApplication {
public static double score(double score){
if(score >= 90){
System.out.println("A");
[code]...
~Problems~
1. It has no gui, I don't know java fx, is java groove used? awt is useful for creating spam bots in robot class, I know it's not very useful but it's so much fun.
2. the sections where I use the scanner.
[ATTACH=CONFIG]27j.jpg49[/ATTACH]Hello,
I'm having the hardest time getting a program to compile. I'm beginning to think I've downloaded the incorrect version of turtle graphics. This symbol looks foreign and I'm unsure how to find a solution. I have fixed some of the errors since this last picture but I will write out my code. The program takes a photo and converts to gray scale then to sepia
import images.APImages;
import images.Pixel;
import java.util.Scanner;
public class sepia{
public static void main(String [] args){
[Code] ....
So I was going to try to create a program that prompts input and creates a file (That didn't exist before) with that input as name.Then, the program prompts inputs after stating questions such as 1 + 1, then if the user inputs an answer, put "Question # = Correct "or" Wrong.Code SO Far:
Java Code:
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
public class File_Read {
public File_Read() {//File_Read is the Interactive object
[code]....
So that it puts the Correct or Wrong into the file.
I am trying to learn how to use file input/output in addition to exception handling... The problem is my textbook wrote this chapter for a version of Java that hasn't come out yet, so everything I do "according to the textbook" doesn't work. any feedback on correcting these exception errors because I am not sure what is causing them or how to fix them.
I was able to have it display the name of the book in the Book.txt file, but when I added the second part if the file doesn't exist, that's when the errors came up and it wouldn't compile.
import java.io.*;
import java.util.*;
public class DisplayBook
{
public static void main(String[] args) {
try {
File book = new File("Book.txt");
FileInputStream in = new FileInputStream(book);
[Code]...
These are the compilation error messages I am receiving: (I have managed to get it down from 7 errors to just 4, but now I'm stuck)
DisplayBook.java:15: error: unreported exception IOException; must be caught or declared to be thrown
while ((letter = in.read()) != -1) //if file exists, displays book title
^
DisplayBook.java:24: error: unreported exception FileNotFoundException; must be caught or declared to be thrown
[Code] ....
4 errors
I'm developing an application to track the status of a production flow-line and have hit a bit of a snag. When attempting to read saved data I run into this:
Exception in thread "main" java.lang.ClassCastException: flowline.End_Of_File cannot be cast to flowline.Operation
at flowline.Station.checkLoadPreviousStationStatus(Station.java:91)
at flowline.Station.main(Station.java:212)
Java Result: 1
I've been reading up on different methods to saving and retrieving data and have decided ObjectInputStream would be the best option.
The save method works fine, I opted to use a EndOfFile class to determine when I've reached the end of the input stream. The problem is, when my loop encounters this object, it doesn't terminate the loop.
public void checkLoadPreviousStationStatus() throws FileNotFoundException, IOException,
ClassNotFoundException, EOFException, TempArrayOutOfBoundsException{
Object loadOpn = null;
End_Of_File eof = new End_Of_File();
File f = new File(fileName);
[Code] .....
The Operation cast is a cast to the objects my LinkedList contains. The highlighted line is where the exception occurs.
My GUI class:
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
[Code] ....
Eclipse error message:
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
Type mismatch: cannot convert from void to JTextField
at GUI.<init>(GUI.java:58)
at Apples.main(Apples.java:7)
I copied this from a thenewboston tutorial and he uses an old version of java but im pretty sure ive copied character for character!
I know I can calculate the sum of squares as such:
// SumSquares.java: calculate the sum of two squares
class SumSquares {
static int sumSquares(int a, int B)/>/> {
int asquare;
int bsquare;
[Code] .....
But how can I modify the code so that it inputs a list of integer values in the range of -100 to 100 from the keyboard and computes the sum of the squares input values. And how would I go about using exception handling to ensure that the input values are in range and are legal integers.
I'm trying to make a puzzle that gets the user input and moves the rows either to the left or right, the columns move either up or down depending on what the user wants. The problem I'm getting is a type mismatch for my RL method which moves the rows to the left.
import java.util.*;
import java.io.*;
public class Numbrosia {
static int [][] board = new int [5][5];
public static void main(String[]args){
Scanner scan = null;
try{
[code]....
I have a simple doubt
float k = 0;
k+=0.2;
k=k+0.2; // here compilation error
compliation error Type mismatch: cannot convert from double to float
My question is why not a complilation error at k+=0.2;
I'm trying to read lines from a textfile and count all the words using String Tokenizer. However I keep getting an error "Unhandled exception type FileNotFoundException" on my IDE(Eclipse) referring to lines 13 and 8. When I let the IDE automatically, and I've even tried typing this manually, insert a try-catch block more errors show up concerning inputFile. When I insert the throws FileNotFoundException for each method it compiles but after running it gives me a FileNotFoundException for textfile.txt. What's even more interesting is that when I copy the .java file out of the IDE project folder, place it in a random empty folder on the Desktop with the textfile.txt, and try running it through command line, it gives a NoSuchElementException: No line found.
import java.util.Scanner;
import java.util.StringTokenizer;
import java.io.*;
[Code].....
I want to catch the exception in my program is the below way:
class Temp
{
public static void main(String s[])
{
try
{
int x=10/s.length;
System.out.println(x);
[Code] ....
I am expecting my program should give output as "java.lang.ArithmeticException: / by zero" but is giving
Temp.java:11: error: ')' expected
catch (ArithmeticException e | ArrayIndexOutOfBoundsException e)
^
Temp.java:11: error: ';' expected
catch (ArithmeticException e | ArrayIndexOutOfBoundsException e)
^
Temp.java:16: error: 'catch' without 'try'
catch (Exception e)
^
Temp.java:22: error: reached end of file while parsing
}
^
4 error
How should null pointer exception be avoided in a program. Should each and every place of access of a variable be checked for null and if null is there own customized exception should be thrown. Is this approach correct for avoiding null pointer exception.
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