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.
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I have two Java classes: User and UserIO
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//User.java
package business;
public class User {
private String firstName;
private String lastName;
private String emailAddress;
public User(String firstName, String lastName, String emailAddress){
below is my code and this exception was thrown in another page so I created a new page and only imported just a single package still its throwing an exception? Any reasons why?
In reference to the book "Head First Servlets and JSP, 2nd edition", chapter-3(), page-81, the command to compile the servlet file to the desired location is
(from the same directory as can be confirmed from the attachment of screenshot of error). this code is in accordance to the location of the respective files in my system, in particular the servlet-api.jar file.
After doing this, my computer is showing the error : file not found.
How do I resolve this? Actually, I don't understand completely what this code is trying to accomplish.
I'm trying to compile one of my Selenium WebDriver .java files to run from the command line. Since it's just one file, I only need to compile the file into a .class file to run it from the cmd line. I don't need to make a .jar file.
The .java file runs fine inside Eclipse, so now I need to make it run from the windows command line.
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;
class SubB{ public void foo(){ System.out.println(" x"); } } public class X extends SubB { public void foo() throws RuntimeException{ super.foo(); if(true) throw new RuntimeException(); System.out.println(" B"); } public static void main(String [] args){ new X().foo(); } }
Why the foo method of class X is not throwing a compile error because according to the override rule, if the superclass method has not declared exception, the subclass method can't declare a new exception...
I am trying to create a program for class the uses two dimensional arrays. I am stuck on the second step that states Use two parallel arrays. One is a two-dimensional array -- a row of this array will hold six values in this order: [0] number of hours worked, [1] hourly pay rate, [2] gross pay, [3] net pay, [4] federal withholding, and [5] state withholding.
This is what I have so far:
Java Code:
double [][] data = new double [30][6]; String [] names = new String [30]; String str = null; String detail = null; int n = input(data, names, inputFile); mh_sh_highlight_all('java'); (there's more but i don't believe it pertains to this question)
My question is how would I create this array. Or, is that right above? I've searched online and in my book and I just don't understand.
I've been trying to pull data from another class file "Calculations.java" and have it be displayed in a TextField in "DataAnalyzerGUI.java". Here is how the hierarchy is broken down for my assignment:
I am stuck with my application. I have jsp, servlet application with jasper report server. When I run the application through eclipse, everything works perfectly. But When I try to run it in Tomcat (without eclipse) it gives me the "Unable to resolve the class file " error. I tried all the solutions I got through the google, but still I am unable to come over it.
again i am facing problem i am able to run Listener class also the ContextListener is initialised but it is giving me error on Tomcat 6.0 command prompt
Here is my Listener Class Sample.java i am able to compile the code but it is giving java.lang.nullpointer exception at runtime on Tomcat.exe Is there is problem in my code
I'm trying to load a class file into Oracle using loadjava and I get the following error:
ORA-29552: verification warning: java.lang.UnsupportedClassVersionError: helloworld (Unsupported major.minor version 51.0)
Presumably this is related to an inconsistency between the jdk that I used to compile helloworld and the Oracle JVM? Or something like that?
My JAVA_HOME is C:Program Files (x86)Javajre7bin My javac version used to compile the code is javac 1.7.0_15 java -version is "1.7.0_15" When I do a find on java.exe in the oracle installation directory (I'm running 11.2) I get
Trying to deploy the application with webService project fails with below error
weblogic.j2ee.dd.xml.AnnotationProcessException: [EJB:015001]Unable to link class oracle.apps.scm.productCollaboration.common.businessClasses.businessClassesService.applicationModule. server.BusinessClassServiceImpl in Jar /scratch/software/mw_local/FMWTOOLS_11.1.1.7.0_GENERIC_121222.1001.2_PATCHES4FA_11.1.1.7.0_PLATFORMS/jcyril/mw_home_standalone/user_projects/domains/fusion_domain/servers/AdminServer/upload/ProductLifecycleManagementApp
For reference I am programming Java in BlueJ. I am fairly new to the language and I am having trouble with sorting.
I am trying to call / test all of the 5 sorting methods (at the same time) in the main class. To be specific, the sorted list has to technically outputted 5 times.
I figured out how to call / test Quicksort:
Sorting.quickSort(friends, 0, friends.length-1);
But the others are not working correctly. Specifically these:
For reference, this is the output when it is not sorted:
Smith, John 610-555-7384 Barnes, Sarah215-555-3827 Riley, Mark 733-555-2969 Getz, Laura 663-555-3984 Smith, Larry464-555-3489 Phelps, Frank322-555-2284 Grant, Marsha243-555-2837
This is the output when it is sorted:
Barnes, Sarah215-555-3827 Getz, Laura 663-555-3984 Grant, Marsha243-555-2837 Phelps, Frank322-555-2284 Riley, Mark 733-555-2969 Smith, John 610-555-7384 Smith, Larry464-555-3489
This is the class Sorting, which I should note is all correct:
public class Sorting{ /** * Swaps to elements in an array. Used by various sorting algorithms. * * @param data the array in which the elements are swapped * @param index1 the index of the first element to be swapped * @param index2 the index of the second element to be swapped */ private static <T extends Comparable<? super T>> void swap(T[] data, int index1, int index2){ T temp = data[index1]; data[index1] = data[index2];
[Code]...
This is the Main class in which I am supposed to call the sorting methods, SortPhoneList:
public class SortPhoneList{ /** * Creates an array of Contact objects, sorts them, then prints * them. */ public static void main (String[] args){ Contact[] friends = new Contact[7]; friends[0] = new Contact ("John", "Smith", "610-555-7384"); friends[1] = new Contact ("Sarah", "Barnes", "215-555-3827");
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;
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?
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?
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.
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 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.
"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"); } }
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
