Trying To Make Java For Telephone Keypad But Won't Compile?
Apr 18, 2014
I'm having problems with the public static void main(String args[]) part. Everything else is correct before this, my teacher has checked that. I have been trying to research why it won't compile right and can't find any errors.
/*
Chapter 6:Telephone
Purpose:This project displays a telephone keypad you can use to type in a phone number.
*/
import java.awt.*;
import java.datatransfer.*;
import java.awt.event.*;
import javax.swing.JOptionPane;
public class Telephone extends Frame implements ActionListener
import java.util.Scanner; public class Bill { public static void main(String[] args) { Scanner console = new Scanner(System.in); //final variables Premium Service final double monthlyChargeP = 25.00; final double FordayminutesP = 0.10;
[Code] ....
I can't find the syntax on {} my block is highlighted red in my application
I'm trying to write a method that returns a number, given an uppercase letter as follows:
public static int getNumber(char uppercaseLetter)
The program is supposed to prompt the user to enter a phone number as a string. The input number may contain letters. The program translates a letter (upper- or lowercase) to a digit and leaves all other characters intact.
My code is below:
import java.util.*; public class PhoneKeypad { public static void main(String[] args){ System.out.print("Enter a string: "); Scanner input = new Scanner(System.in); String phNumber = input.next();
[Code] ....
I am getting these errors: java.lang.ClassFormatError: Duplicate field name&signature in class file Chapter9/PhoneKeypad at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
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in regular notepad as .java laso and it doesnt work iv done every thing i could possibly find on youtube is this stuff outdated ?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 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.
Why can't I see the text when I compile the java code?
Java Code:
import java.io.*; import java.util.logging.Level; import java.util.logging.Logger; import javax.imageio.ImageIO; import javax.swing.*; public class WorldTravel { public static void main (String[] args){ JFrame f = new JFrame("World Travel!"); BG_text p = new BG_text();
I am looking for a way to compile Java Source-Files at runtime and save them all in an executable jar; almost like an IDE would do. I know that there is the javax.tools package which provides a JavaCompiler interface and you can use ToolProvider.getSystemJavaCompiler() to get an instance of a compiler. However, this method has one important problem: it only works on machines that have the JDK installed. Not when only the JRE is installed.
I guess at this point that I need some kind of third party library that offers an implementation of a JavaCompiler. Unfortunately, this is really complicated to search for on the internet since all top listings when searching "compile java at runtime jre" do not really provide a solution to the problem.
I am writing a (somewhat) complex simulation software right now which is supposed to be used by people who have absolutely no knowledge of programming. At the same time, this software should provide the user with a certain amount of flexibility and control over the flow of the simulation.
My previous take on this problem was to build a complex system to interprete user settings from a GUI. I would basically read the GUI input, output it to some kind of own scripting syntax which I just quickly made up and have that interpreted at runtime. Then I realized, that is a silly concept and I threw it out before I got far into the developement. The much better solution I came up with is taking the input from the GUI, create java source code from it and compile it at run-time. Seems much cleaner and nicer to me; will also probably have a better performance, but thats not really an issue anyways.
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 keep getting this error when compiling the code . I think its got to do with the Tomcat server not working well with the textpad app...I'm using windows 8.1(for the course I have to use Textpad 4.7.3 & Apache Tomcat 5.5.7 Server) :
C:UsersReignDownloadsIntec - Codecourse technology59850dChapter 12WorkWebStocks.java:20: package javax.servlet does not exist import javax.servlet.*; ^ C:UsersReignDownloadsIntec - Codecourse technology59850dChapter 12WorkWebStocks.java:21: package javax.servlet.http does not exist import javax.servlet.http.*;
[code]....
tom cat is running as a service it shows started in the tom cat app and as a running service in windows services !!!
I 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.
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...
Develop an algorithm for a Java program that takes as input a single letter and displays the corresponding digit on the telephone. The letters and digits on a telephone are grouped this way:
The screen dialog might look like this: Enter a single letter, and I will tell you what the corresponding digit is on the telephone. R The digit 7 corresponds to the letter R on the telephone.
The program should display a message indicating that there is no matching digit for any non-alphabetic character entered by the user. Also, the application should recognize only uppercase letters. If a user enters a lowercase letter, the program should display an error message. Prompt the user with an informative message for the input value as shown above.
The application should include the input letter as part of the output.
Write the algorithm to solve this problem including steps for prompting the user, getting input from the keyboard, and displaying the results.
Write the Java program that you designed, using your algorithm as a guide. Use your algorithm as comments in the body of the main method.
Use proper indentation, and meaningful identifiers throughout the code.
Write an interface Directory to manipulate entries in a telephone directory for the University. The interface must support the following operations:
1) The ability to insert new entries into the directory. Entries should be stored in alphabetical order of surname. 2) Delete entries from the directory either by name or number 3) Provide a lookup method that will find the extension no of a member of staff given his/her name. You should try to make this method run as efficiently as possible. 4) Change a person's telephone number 5) Print the telephone directory in a neatly tabulated fashion.
Write a class ArrayDirectory that implements this interface using an array to store the telephone directory information. The class must store the surname and initial for each member of staff and their telephone extension (a four digit number which may start with a zero). You may find it useful to define a class Entry to store information about individual entries. The entries should be read into the array from a text file consisting of multiple lines in the following format:
Surname<tab>Initials<tab>Telephone extension
Write a main program that reads in data from a file and then tests all the methods of your class interface. Note it is not necessary to write data back to disk (even if it has changed) in this project.
For data insertion and lookup, you should measure the performance for the average case (e.g. looking up a record in the middle of the data). To do this you can use the static method System.currentTimeMillis() which returns the time in milliseconds. To get an accurate measure of the time to perform an operation it is a good idea to perform each operation 1000 (or even 10000) times and measure the time taken. This will remove any problems due to the system clock having a coarse granularity (not ticking very often). Make sure you only time the method and not any input/output associated with it. Your documentation should include a discussion of these results.
Part 2
You decide that your solution to part 1 may be too slow to be useful when used with a real large telephone directory and make the following changes to attempt to improve the performance of your program:
1). Provide a second implementation (ListDirectory) of the Directory interface using the Java Collections List interface and LinkedList classes. 2). The changes in 1) should make adding, deleting and modifying records more efficientbut will probably reduce the time to lookup numbers. To overcome this you use a technique called hashing. Instead of storing all the records on one list you use a series of lists. The data for all people whose surname begins with "A" is stored on the first list, records for all people whose surname begins with "B" on a second list and so on. Write a third implementation (HashDirectory) of the Directory interface using this technique.
Again, you should measure the performance for the best, worst and average cases of implementations 1) and 2) above. Compare the efficiency of each of the 3 implementations in your documentation.
Part 3
Choose one of your 3 implementations from Parts 1 and 2 and embed it in a graphical user interface that allows users to perform all the methods in the Directory interface using a mouse and keyboard appropriately.
Write a program to calculate the telephone charges for four customers. The data for each customer consists of NAME, PREVIOUS METER READING, PRESENT METER READING. The difference between the two readings gives the number of units used by the customer for the period under consideration.
The amount due for each customer is calculated by: UNITS USED * RATE PER UNIT + RENTAL CHARGE The rate per unit and rental charge is assumed to be the same for all customers and must be input once only.
Your program must:
a. Input the rate and rental charge b. Read the data for each customer and calculate the amount due c. Print the information under suitable headings d. Calculate and print the total amount due to the telephone company
I am having some trouble with this program. The assignment is to write a program, given a seven-digit phone number, uses a PrintStream object to write to a file every possible seven-letter word combination that corresponds to that number. I have to avoid using 0 or 1. Here is my code.
import java.io.FileOutputStream; import java.io.IOException; import java.io.PrintStream; import java.util.Scanner; public class TelephoneGenerator { String phoneNumber; char numberLetters[][] = {
[Code] ....
I am getting an error dealing with the main class.
I'm trying to put together a method that formats telelphone numbers, but there's a part of my code that not working. If I enter (305)912-5458 into the variable phoneNumb I get an index is out of range error. I added a lot of system out messages so that I can try to get an idea of why the code was crashing.
public static void main(String[] args) { int intBegin = 0; int intEnd = 1; int length; String charact; StringBuilder numbuilder = new StringBuilder();
[Code] .....
The error message I'm getting is:
run: The length is 13 intBegin is at 0 intEnd is at 1 index is at 0 Charcter ( was not inserted
I have a Database with Data of people (name, adress, phone number).
If a user enters a phone number (CLIENT) -> the correct person with the name and adress should appear.
I build up the infrastructure and now I'm at the point that I have to create a Webmethod for it. I just worked on projects like addition of two integers, hello "name", ... I think this example now is harder, BUT i can learn a lot!
this is the following task i am trying to do. Write an interface Directory to manipulate entries in a telephone directory for the University. The interface must support the following operations:
1) The ability to insert new entries into the directory. Entries should be stored in alphabetical order of surname. 2) Delete entries from the directory either by name or number 3) Provide a lookup method that will find the extension no of a member of staff given his/her name. You should try to make this method run as efficiently as possible. 4) Change a person's telephone number 5) Print the telephone directory in a neatly tabulated fashion.
Write a class ArrayDirectory that implements this interface using an array to store the telephone directory information. The class must store the surname and initial for each member of staff and their telephone extension (a four digit number which may start with a zero). You may find it useful to define a class Entry to store information about individual entries. The entries should be read into the array from a text file consisting of multiple lines in the following format:
Surname<tab>Initials<tab>Telephone extension
The part that i am stuck on is trying to do the entry method, delete entries method, loop up method, change persons telephone number and be able to print it.
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 {
I am trying to make a calculator using Java GUI. I've managed to make an ActionListener and add it to a button, but I've made an error in my code that I'm unsure of how to solve. Because of how I've written the code, only one number can be placed in the text field. For example, the an ActionListener for the three button on the calculator was added to the button, but no matter how many times the user presses the button, only one 3 will appear in the text field. The code is below:
import javax.swing.*;//import the packages needed for gui import java.awt.*; import java.awt.event.*; public class Calculator { public static void main(String[] args) { JFrame window = new JFrame("Window");//makes a JFrame window.setSize(300,350);
[code].....
As you can see, because the compiler forces the String variable to be final, so when the user presses the button, the code simply shows how a space character and three character would look like, because the String variable can't change. How do I write my code so that every time the user presses the button, a character is added to the text field?
I would like to make a database using HTML and Java. I already made something like this using swing. I am just looking for some pointers here. I just started looking into Java Play 2 and I have a feeling this is what I am looking for. JavaEE is very complicated and I have read that it is being phased out. What is your opinion on this?
I want to make a static HTML page and put it on my home network and treat one of my computers as the sever accessing mySQL.
I want a completely unique GUI with unique buttons, like I could make it a giraffe if I wanted to! (not going to, but a giraffe seemed like a pretty irregular shape) ....
