if(false){}
but this is not
for(;false;){}
both will in theory never go in more interestingly this will compile
for(;false == false;){}
To me it seems like this is a parsing issue that could have been solved by the people who originally wrote the parser but they made a decision that there must be a relational operator in the condition declaration.
I am trying to print a loop inside an array of a greater size than the loop itself. Like for example I have an array of size 7 but it has only 3 elements.
int[] array=new int[7]
array[0]=2;
array[1]=3;
array[2]=4;
now what I want to do is print these three numbers in a loop so that my array[3]=2;array[4]=3;array[5]=4 ...... till the last one. Also the array could be any size and not just 7.
Here's the code: it's while loop inside a for loop to determine the proper length of a variable:
for (int i = 0; i < num; i++) {
horse[i]=new thoroughbred();
boolean propernamelength = false;
while (propernamelength==false){
String name = entry.getUserInput("Enter the name of horse "
[code]....
I was just wondering what was going on here -- I've initialized the variable, so why do I get this message? (actually the carat was under the variable name inside the parentheses.
I have everything else working. My problem is that when i type "quit" to close the outer loop. It still runs the inner loop. The National Bank manager wants you to code a program that reads each clients charges to their Credit Card account and outputs the average charge per client and the overall average for the total number of clients in the Bank.
Hint: The OUTER LOOP in your program should allow the user the name of the client and end the program when the name entered is QUIT.In addition to the outer loop, you need AN INNER LOOP that will allow the user to input the clients charge to his/her account by entering one charge at a time and end inputting the charges whenever she/he enters -1 for a value. This INNER LOOP will performed the Add for all the charges entered for a client and count the number of charges entered.
After INNER LOOP ends, the program calculates an average for this student. The average is calculated by dividing the Total into the number of charges entered. The program prints the average charge for that client, adds the Total to a GrandTotal, assigns zero to the Total and counter variables before it loops back to get the grade for another client.Use DecimalFormat or NumberFormat to format the numeric output to dollar amounts.
The output of the program should something like this:
John Smith average $850.00
Maria Gonzalez average $90.67
Terry Lucas average $959.00
Mickey Mouse course average $6,050.89
National Bank client average $1,987.67
Code:
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String name = "";
int charge = 0;
int count = -1;
int total = 1;
int grandtotal = 0;
int average = 0;
[code]....
I'm doing a project and my code won't compile.
import javax.swing.*;
import java.awt.event.*;
public class BookStore extends JFrame{
private JPanel panel;
private JLabel question; //This will be where the question is.
private JTextField NumofBooks; //this is where the user will enter the number of books
private JButton OKButton,ClearButton,ExitButton; //Will give the user the points, cancel the points, and exit
private final int WINDOW_WIDTH = 310; //Need to make it visible
private final int WINDOW_HEIGHT = 100;
[code]....
i would like to ask what does exactly do the command mvn compile. What is happening with the code, when i write this command? And why is it necessary for running the code?
View Replies View RelatedThis is my TagHandler class
package foo;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.SimpleTagSupport;
import java.io.IOException;
[Code] ....
But it is not able to find all the classes referenced in the code. While compiling I am mentioning the servlet-api.jar
My compilation statement is this
C:Tomcat 7.0webappsSimpleCustomTagsWEB-INF>javac -cp "C:Tomcat 7.0libservlet-api.jar;.;" classesfoo*.java
It says package javax.servlet.jsp.JspException and javax.servlet.jsp.tagext.SimpleTagSupport does not exist.
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?
import java.util.Calendar;
import java.util.GregorianCalendar;
public class CalendarCalc {
public CalendarCalc (){}
private static void printCalendarMonthYear (int month, int year)
[Code] .....
IDE is telling me this:
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The method printCalendarMonthYear(int, int) is undefined for the type CalendarDisplay
at CalendarDisplay.main(CalendarDisplay.java:46)
Btw, I have a main class. This is just the class responsible for doing calculations.
i am trying to work through the Murach's Java Servlets and JSP book. I am stuck however. I keep getting a HTTP Status 500 - Unable to compile class for JSP.
I am using Eclipse Kepler, JDK 1.7, and Tomcat v7.0 server.
Its a fairly simple program that takes in user information, first name, last name, and an email and processes the information, saving the data to a text file.
------------------------------------------------
I have two Java classes: User and UserIO
-------------------------------------------------
//User.java
package business;
public class User {
private String firstName;
private String lastName;
private String emailAddress;
public User(String firstName, String lastName, String emailAddress){
[code]....
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 RelatedThe MyCircle class won't compile.
QUESTION: A class called MyCircle, which models a circle with a center (x, y) and a radius, is designed as shown in the class diagram. The MyCircle class uses an instance of MyPoint class (created in the previous exercise) as its center.
The class contains:
-Two private instance variables: center (an instance of MyPoint) and radius (int).
-A constructor that constructs a circle with the given center's (x, y) and radius.
-An overloaded constructor that constructs a MyCircle given a MyPoint instance as center, and radius.
-Various getters and setters.
-A toString() method that returns a string description of this instance in the format "Circle @ (x, y) radius=r".
-A getArea() method that returns the area of the circle in double.
Write the MyCircle class. Also write a test program (called TestMyCircle) to test all the methods defined in the class.
My code:
public class MyCircle{
private MyPoint center;
private int radius=1;
public MyCircle(int x, int y, int radius){
this.x = x;
this.y = y;
this.radius = radius;
[code]....
I am a C# developer but need to do some java development. The code produces the following error.
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
...
HashMap<String, String > myMap = new HashMap<String, String>(){{
put("a","b");
}};
myMap.put("foo", "bar");
myMap.put("Sna", "foo");
...
Generates this error
C:/FSC/apache-tomcat-6.0.41/webapps/aspen/temp/x2_8656248460570782763/x2_5214718769032742331/StudentExport.java:47: error: <identifier> expected
myMap.put("foo", "bar");
^
What am I missing?
"Because X is a compile time constant, the compiler will Y"... But what exactly is a compile time constant? And how can we determine whether something is treated as such?Obviously, a compile time constant is a constant value that is known at compile time... ... Literals are, by definition, compile time constants -- as they are constants, known at compile time.
But the definition of a compile time constant is a bit more complex. To start, let's examine section 15.28 of the Java language specification.A compile-time constant expression is an expression denoting a value of primitive type or a String that is composed using only the following:
Literals of primitive type and literals of type String Casts to primitive types and casts to type StringThe unary operators +, -, ~, and ! (but not ++ or --)The multiplicative operators *, /, and %The additive operators + and - The shift operators <<, >>, and >>>The relational operators <, <=, >, and >= (but not instanceof)The equality operators == and !=The bitwise and logical operators &, ^, and |The conditional-and operator && and the conditional-or operator ||The ternary conditional operator ? : Simple names that refer to final variables whose initializers are constant expressions Qualified names of the form TypeName . Identifier that refer to final variables whose initializers are constant expressions
This is the full definition of a compile time constant. And as you can see, it contains more than just literals. In fact, literals are merely the first bullet point on the list. Also, note that a compile time constant can apply to any literal that is of primative or String type.The next few bullet points are the operations that can be applied to a constant at compile time. This list is actually pretty long, as it is possible to apply most of the operations at compile time. It may actually be easier to remember what can't be apply at compile time -- pre and post increment and decrement, instanceof operator, or any method calls, are not on the list.
The last few bullets are the most interesting. It is possible to use a variable in the expression -- provided that the variable is a compile time constant variable. So... what is a constant variable? Going back to the JLS (section 4.12.4 to be exact)..4.12.4 final Variables.A variable can be declared final. A final variable may only be assigned to once. It is a compile time error if a final variable is assigned to unless it is definitely unassigned (§16) immediately prior to the assignment.
We call a variable, of primitive type or type String, that is final and initialized with a compile-time constant expression (§15.28) a constant variable. Whether a variable is a constant variable or not may have implications with respect to class initialization (§12.4.1), binary compatibility (§13.1, §13.4.9) and definite assignment (§16).The last part of the definition is the relevant part (I still find it amazing that this is that well hidden in the specification). To be a variable that is a compile time constant, the variable needs to be...declared as finalhave a primative or String typeinitialized (on the same line as the declaration)assigned to a compile time constant expression.
I'v tried everything, i'v tried to create new path in enviornment variables i tried adding this path -->(C:Program FilesJavajdk1.8.0_20bin) to the end of the default path doesnt work i uninstalled and reinstalled and did the same thing over and it didnt work am i editing the files wrong ? what i do is write the hello world program in eclipse to make sure there arent any errors then copy and paste in note pad++ save it as a .java file and it doesnt work i tried save it in regular notepad as .java laso and it doesnt work iv done every thing i could possibly find on youtube is this stuff outdated ? is there a new way? this one one of the errors ill get
C:javat>javac helloworld.java
helloworld.java:1: error: '{' exp
public class helloworld.java {
^
And this is the code for that file im trying to compile
public class helloworld.java {
public static void main (String args[]){
System.out.println("hello world");
}
}
so i followed a tutorial on youtube called "Java Game Development with Slick" - by thenewboston,URL....okay, so i have made my game / program, and now i just want to export it to a jar file that people can double click and play..unfortunately when i double click the .jar file nothing happens...i get the little "loading" thingy on my courser but it disappears after about 5 seconds and then nothing happens :(the way i made it into a jar file is by doing the following:
-right clicked my java project..
-clicked on "export"..
-clicked on java / Runnable JAR file
-filled in the stuff, (JARs destination ect..)
-pressed finish..
-then i got a jar file on my desktop and double clicked it....but as i said....nothing happens
Since I done a recent git pull on my project, for some reason now Im getting an error when starting Tomcat and rendering the index.jsp, but I dont understand whats changed, as this was working before.
The error:
org.apache.jasper.JasperException: /index.jsp (line: 4, column: 42) File "/blog.postTags" not found
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:42)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:443)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:133)
org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:168)
org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1427)
The index.jsp:
<!DOCTYPE html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="p" uri="blog.postTags" %>
<html>
<head><title>Blog Home</title></head>
<body>
<h1>Blog Home</h1>
<br />
<% out.println("Your IP address is " + request.getRemoteAddr()); %>
[code]....
I really am unsure as to why this has stopped working, I even rolled back to an earlier commit and this was definitely working before, but I havent changed anything, Initially when you start Tomcat is shows another error in the browser, but on a refresh its a null on this tag library?
I have set the CLASSPATH
(C:Program FilesApache-Tomcat-7apache-tomcat-7.0.53libservlet-api.jar,
PATH(C:Program FilesJavajdk1.7.0_51in)
and JAVA_HOME
(C:Program FilesJavajdk1.7.0_51) environmental variable on my windows XP.
I installed tomcat server and its running fine. I made my first servlet(DemoServlet.java) in
C:Program FilesApache-Tomcat-7apache-tomcat-7.0.53webappsDEMOWEB-INFclasses folder.
I made the XML file (web.xml) in C:Program FilesApache-Tomcat-7apache-tomcat-7.0.53webappsDEMOWEB-INF folder. In command prompt I went to the classes folder
(C:Program FilesApache-Tomcat-7apache-tomcat-7.0.53webappsDEMOWEB-INFclasses).
And tried to compile my servlet(javac DemoServlet.java) but it is showing file not found error. I am new to servlets.
I am totally new to programming in every way, shape or form, and I'm working my way through the Head First Java book (2nd ed). I have just finished copying the code for the initial BeatBox app, the one starting on page 420. When I try to compile it, I get these errors:
BeatBox.java:36: cannot find symbol
symbol : constructor Box(int)
location: class Box
Box buttonBox = new Box(BoxLayout.Y_AXIS);
^
BeatBox.java:40: cannot find symbol
symbol : method add(javax.swing.JButton)
location: class Box
buttonBox.add(start);
[code]....
I doubt that this is relevant, but I'm running Mac OS X, coding in TextWrangler and compiling with Terminal. Java version is 1.6.0_24.
programming altogether and after almost reaching half way in the 'Head first java' book I decided to try and apply some of what I've learnt so far and write my first 'Object orientated' program. As this is pretty much the first program I've ever written, I decided to write a program to ask for two integers and add them both together and then present them to the user (the goal eventually being a basic fully working command line calculator with +,-,* and /. I'm expecting many compile errors but not the following errors below.
I have three .java files contained within a folder and after trying to figure out how to compile all three files (as they use one another) all at once, I came across this ---> javac *.java
so I typed this in the command line whilst in the directory containing the three files assuming *.java is the best approach and then I receive the following errors:
inputOutput.java:10: error: cannot find symb
c.addition() = intIn.nextInteger();
^
symbol: variable c
location: class inputOutput
[Code].....
import java.util.*;
import java.lang.*;
class Bank {
String name;
float acc_no,balance;
void accept(String str, float no, float bal)
[code]....
error: cannot find symbol Place
I'm trying to use the javac -sourcepath option to compile superclasses without explicitly naming them. I've been looking at examples, other posts, and trying variations for a while without success.
I have:
package ActorBase0.classes;
public class Bridge extends Place {
......
Place is also in package ActorBase0.classes and the source files are in the same directory .... ActorBase0sources
javac -d ActorBase0classes -sourcepath ActorBase0sources -cp . -Xlint:unchecked -verbose ActorBase0sourcesBridge.java
is one of the variations that gets error: cannot find symbol Place.
How do I set the class path, the path, compile and run java programs using jdk and jcreator?
View Replies View RelatedI made just a simple hello world class and i can not seam to make eclipse run it in any way not even the console.
View Replies View RelatedI'm writing basically my first program for school. I've written small ones, following instructions, but this is the most vague. I'm having issues. I can't figure out what the error means. I'm not done with the code, but I think the ArrayList is throwing me off. I'm trying to gather user input and sum the total. Here's the code:
package graduationplanner;
import java.util.ArrayList;
import java.util.Scanner;
import java.lang.Double;
public class GraduationPlanner {
public static void main(String[] args) {
[Code] ....
I am having a pretty bad time with this y goto to classes one form labels with a certain image and the other for another images of the same kind but what i have to do is to use a third class in which both classes have to compile and appear in the right place. Ineed an example or something because i don't get it what to do?
View Replies View Related