Error Cannot Find Symbol In Java

Java error: cannot find symbol IoException?

I am enrolled in a Java class, we are working on Writing and Reading information to/from a file. I am having issues with my WriteData.java code. I receive the following error:

WriteData.java:5: error: cannot find symbol
public static void main(String[] args) throws IoException {
^

symbol: class IoException
location: class WriteData
1 error


My code is as follows:

public class WriteData {

public static void main(String[] args) throws IoException {
java.io.File file = new java.io.File("scores.txt");
if (file.exists()) {
System.out.println("File already exists");
System.exit(1);

}

// create a file
java.io.PrintWriter output = new java.io.PrintWriter(file);

// write formatted output to the file
output.print("John T Smith ");
output.println(90);
output.print("Eric K Jones ");
output.println(85);

// close the file
output.close();

}

}


Any help will be appreciated. I am not understanding WHY the IoException is not recognized.

Java Error...Cannot find symbol - class?

JPanel is in javax.swing

You need to add:

import javax.swing.JPanel;

You could just use:

import javax.swing.*;

Cannot find symbol class Pause? Java 5?

I can't find a way to call the Pause method and insert the symbol class to make this work. I have to input that I'm looking for a number between 1 and 20 and I have to make the program wait five seconds before giving the number.

It's the Pause wait, instantiating and calling the method that's messing me up.

Can someone help please?

LinkedList in java cannot find symbol?

i dont know how to solve this error please help me

import java.io.*;

public class Lk
{
public static void main(String[] args)
{
LinkedList names = new LinkedList();
names.add("A");
names.add("B");
names.add("C");
names.add("D");
names.add("E");
names.add("F");
names.addfirst("Q");
names.addlast("S");
System.out.println("Value of LinkedList:" + names);
names.remove(2);
names.remove(1);
System.out.println();
System.out.print("The value of LinkedList:" + names);

}
}




error :
C:\mywork\LinkedList\Lk.java:7: cannot find symbol
symbol : class LinkedList
location: class Lk
LinkedList names = new LinkedList();
^
C:\mywork\LinkedList\Lk.java:7: cannot find symbol
symbol : class LinkedList
location: class Lk
LinkedList names = new LinkedList();
^
2 errors

Java error:cannot find symbol variable output label?

I have tried many things, and since I'm new to java I really don't know what to try.

Here is my code:
/*
Chapter 3: The Body Mass Index Calculator
Programmer: J. Starks
Date: October 20, 2007
Filename: BodyMassApplet.java
Purpose: This project calculates the body mass index based
on a person's height and weight.
*/

import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class BodyMassApplet extends Applet implements ActionListener
{
//declare variables
Image logo; //declare an Image object
int inches, pounds;
double meters, kilograms, index;

//construct components
Label companyLabel = new Label("THE SUN FITNESS CENTER BODY MASS INDEX CALCULATOR");
Label heightLabel = new Label("Enter your height to the nearest inch: ");
TextField heightField = new TextField(10);
Label weightLabel = new Label("Enter your weight to the nearest pound: ");
TextField weightField = new TextField(10);
Button calcButton = new Button("Calculate");
Label outputlabel = new Label("Click the Calculate button to see your body mass index.");

public void init()
{
setForeground(Color.red);
add(companyLabel);
add(heightLabel);
add(heightField);
add(weightLabel);
add(weightField);
add(calcButton);
calcButton.addActionListener(this);
add(outputLabel);
logo = getImage(getDocumentBase(), "logo.gif");
}

public void actionPerformed(ActionEvent e)
{

inches = Integer.parseInt(heightField.getText());
pounds = Integer.parseInt(weightField.getText());
meters = inches / 39.36;
kilograms = pounds / 2.2;
index = kilograms / Math.pow(meters,2);
outputLabel.setText("YOUR BODY MASS INDEX IS " + Math.round(index) + ".");
}

public void paint(Graphics g)
{

}
}

and the error is:
F:\BodyMassApplet.java:40: cannot find symbol
symbol : variable outputLabel
location: class BodyMassApplet
add(outputLabel);
^
F:\BodyMassApplet.java:52: cannot find symbol
symbol : variable outputLabel
location: class BodyMassApplet
outputLabel.setText("YOUR BODY MASS INDEX IS " + Math.round(index) + ".");
^
2 errors

Cannot find symbol error in Java program? help please!?

this error keeps showing up when i compile my program:

pg2a.java:23: cannot find symbol
symbol : method substring(java.lang.String)
location: class java.lang.String
String character = input.charAt(0, input.substring(" "));

can anyone help me figure out whats wrong with it? It points to the period between input and substring. Here is the rest of the program:

import java.util.Scanner;

public class pg2a {

public static void main(String[] args) {

Scanner keyboard = new Scanner(System.in);

String userName;

System.out.print("Enter your name:");
userName = keyboard.next();
System.out.println("Choose a character: Pikachu, Charmander, Squirtle, or Bulbasaur. Capitaliza the first letter. Enter a level between 1 and 15.");
String input = keyboard.next();
String character = input.charAt(0, input.substring(" "));
int level = input.indexOf(" ");
System.out.println("Added level " + level + character + " for " + userName);

boolean change = false;

if (level > 1 || level < 15) {
System.out.println("Invalid level!");
change = true;
}





}
}