Why Narrowing Conversions Unsafe In Java
Nov 5, 2014I had learned that narrowing conversion are called unsafe but unable to know why.
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Calculations / Conversions - Calculate Correct Amount Of Change Due To A Customer
Sep 12, 2014Here are the instructions to my assignment:
A shopkeeper in Diagon Alley needs you to write a program that will calculate the correct amount of change due to a customer. (In Diagon Alley they use three coins with different values, given below).
1. Prompt the user to input the amount of sale in Galleons, Sickles, and Knuts.
2. Prompt the user to input the amount of money given by the customer in Galleons, Sickles, and Knuts.
3. Create constants that represent:
a. 1 Galleon = 17 Sickles
b. 1 Sickle = 29 Knuts
4. Perform the necessary calculations and conversions to compute the correct change in the least number of coins.
5. create a formatted receipt recording the entire transaction.
Here are what is steps 1 and 2 and 5 but problem with are 3 and 4. I need to create the constants and use proper conversions to give the right amount of change back.
Java Code:
import java.util.Scanner;
public class OperatorFormatting {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Welcome to Flourish and Blotts");
[Code] ....
Basically, on steps 3 and 4 which are creating the constants and using the to make the proper conversions to give the customer the proper amount of change Due.
Hiding Unsafe Methods Through Polymorphism
Feb 17, 2015Recently I have been thinking of using additional interfaces in one of my libraries to hide certain "unsafe" methods of my classes from the user. I would like to get the opinion of other, more advanced java programmers on this issue.
What I do is something like the following (heavily simplified):
public interface ReadOnly {
public int getValue();
}
public interface ReadWrite extends ReadOnly {
public void setValue(int value);
[Code] ....
The user would have access to the ExternalInterface. The ExternalInterface is controlling the values of the InternalComponent. The user can get the InternalComponent, but typecasted to a ReadOnly which does not expose the setters.
Now the thing is the user can still access the setValue method by typecasting the ReadOnly to an InternalComponent or to a ReadWrite, and that is not bad. If the user knows exactly what he/she is doing this will give him/her more flexibility and more power. But this way it *should* become obvious that this is not the intended use and perhaps the extra work of typecasting will discourage the user from doing this.
Unchecked Or Unsafe Operations While Compiling Program?
Jun 30, 2014String filename="C:UsersRajashekarDesktopfwfwdSoftware Failures1_Test.txt";//Input Files
String data;
public ArrayList<String> value=new ArrayList<String>();
public void read() throws IOException{
File f = new File(filename);
[Code] ....
Applets :: Accessing Java Application Without Adding Site To Java Security
Sep 12, 2014I have tried running the java application without adding the site to site list in java security tab. But I get a sand box message as APPLICATION BLOCKED BY SECURITY SETTINGS. How to run the java application without adding the site to site list in java security tab.
View Replies View RelatedCan Use Java Code From OpenScript Or APIs In Separate Java Program?
Oct 24, 2014I want to develop a Java program that uses OpenScript APIs to test my applications. The OpenScript framework automatically creates the Java Code so I was thinking of either using this code or create my own using the APIs.
I tried both options using NetBeans but I'm getting errors everywhere starting with the library import. I'm pretty new to Java so I'm sure I'm missing a lot of things here. I pasted the code below from the OpenScript framework that want to use in a stand-alone file for your reference.,
import oracle.oats.scripting.modules.basic.api.*;
import oracle.oats.scripting.modules.browser.api.*;
import oracle.oats.scripting.modules.functionalTest.api.*;
import oracle.oats.scripting.modules.utilities.api.*;
import oracle.oats.scripting.modules.utilities.api.sql.*;
[Code] ....
Java Application With Several Classes All In Same Java File
Apr 9, 2015I've written a java application with several classes all in the same .java file. It works just fine. Now, I've broken it up so that each class has its own .java file. Still works fine. My next step is to put those classes into a package, but I'm not about to get the program to run.The .java source files are all in /home/user/src
I've set the CLASSPATH to /home/user/src..All of the source files have "package com.myfirm.program" on the first line.I compiled the application with:
javac -d . File1.java File2.java File3.java (etc...)
the compiler created the directory: /home/user/src/com/myfirm/program and put all of the .class files in there.So how do I get the program to run? if I run from /home/usr/src
java File1
I get: Exception in thread "main" java.lang.NoClassDefFoundError: File1 (wrong name: com/myfirm/program/Program)
How To Call Java Methods From Different Java File
Apr 14, 2015I create 2 files:
CircleCalculationMethod.javaMain.java
In Main.java, How can i call method in CircleCalculationMethod.java ?
Should I put everything in same folder ??Should i do something like "import CircleCalculationMethod.java"Should i do something like create a package ...
I use Eclipse software
What Is Difference Between Java SE And Java EE
Sep 19, 2014The title of Question might seem old and previously asked.But I have a Question that what is difference between javaSE and Java EE.Although I knew what comes under JavaSE and What is under JavaEE.But My question is that.
What happens when we add PATH in our Environment Variable How does Eclipse or Other IDE use it?
Second Question is.
For Java SE we declare a Path Variable but for Java EE we do not add any library?(I know we add some jar file like for Servlet(Servlet-api.jar) and for EJB(Ejb.jar),But What is actaul difference?
Odd Even Zero Java
Oct 23, 2014creating a program that will output something like this:
Enter an Integer: 1405302(user inputted)
Your integer contains 2 even digit(s), 3 odd digit(s), and 2 zero(s).
Using Java For Web
Dec 4, 2014I know about coding in general, Java, C, Python, SQL etc. but I barely know anything about making code come together on the web. I have a vague idea about what things like libraries and frameworks are,I'm interested in making a web application with which relies on Java do to the data processing. The idea is that the user inputs some messages, clicks submit, the text is taken away and processed, and the results are displayed on the screen. I would like the UI to be smooth with a modern look and feel.
Also, I usually do programming on Windows but I could also use Linux, so if I'll come across any specific drawbacks using Windows.
Specify WD Where Java App Is Located
Jan 9, 2015How do I specify the Working directory where the Java app is located? It may be different on different machines.
View Replies View RelatedWhat Is Serialization In Java
Apr 8, 2015what is seriazable.But I am not able to come that why it is used and when should I declare my class(Object) as serialzable and when not?
View Replies View RelatedHow To Create API In Java
Aug 9, 2014i need to develop a API in java. that API will be communicate with the some site. Need to import and export the contacts into that site databases.
View Replies View RelatedUTF-8 Conversion In Java?
Oct 30, 2014When I try to convert this value, "Testingu2120" (along with UTF coed u2120)comes as a string as part of SOAP response. I need to convert this UTF-8 characters in to a symbol, in this case it is SM (Service Mark) symbol and show it on the UI.
How can we achieve this in JAVA?
I have four different UTF-8 character set to convert.
TM - u2122
SM -u2120
R - u00AE
C - u00A9
Run Cmd Commands Through Java?
Sep 17, 2014I would like my application to execute a command in cmd. The command looks like
start "" /D "C:Riot GamesLeague of LegendsRADSsolutionslol_game_client_sln
elease s .0.1.55deploy"
"League of Legends.exe" "8394" "LoLLauncher.exe" ""
"spectator 95.172.65.26:8088 P3hNrXYZlaM3iJ9ximtzJWHbwLhvbimJ 953089676 EUN1"
So my question is how do I do this?
I tried this, (just copy paste the command):
package MyProject;
import java.io.IOException;
import java.io.InputStream;
public class Cmd {
public static void main(String[] args) {
try {
final Process process = Runtime.getRuntime().exec("start "" /D "C:Riot GamesLeague of
[code]....
Tables In Java
Mar 22, 2015We started learning about tables and have a little program. The teacher gave us an excercise and doesn't works (not running), I receive too many errors. So any simple java program with tables with 20 numbers, that is giving random numbers?
View Replies View RelatedUse Of Functions In Java
Feb 4, 2014Write a function (or functions) that given a collection of files will produce a sum of integers from each line of each file. Each file can have any number of lines from 1 to N. Each line can contain only one integer and no other alphanumeric characters. All of the numbers from all of the files should be added to the final result. The result is just one number.
For either, what we are looking for is:
1. Clear separation of concerns
2. Well defined objects / interfaces
3. Application of good OO design principles to solve the problem
4. No code duplication
5. Test Driven Development
6. Well refactored code
7. Well tested code
Customized XML Using Java
Nov 13, 2014I have to create a new project in which i have to take the inputs from the user and create the XML schema out of this. How can I do this the best way .
View Replies View RelatedHow To Run Powershell From Java
Aug 12, 2014I am trying to run a Powershell command from Java that creates an Active Directory group. I don't get any errors, but it doesn't work either. I can take the output from this class and plug it into the CMD prompt and it works fine.
Java Code:
public class CreateAD {
public int creategroup(String groupname, String description){
String runadcreate;
int errorfree =0;
runadcreate = "powershell Import-Module ActiveDirectory
[code]...
JSP :: Converting ASP To Java
Dec 22, 2014I'm converting from ASP to Java for a legacy site. I believe the first part of the if statement is right but I'm having an issue within the else staetment. I'm getting date is undefined, I've tried using getYear and getDate but have not been successful.
ASP:
If Request("action") = "results" Then
aMonth = Request("selMonth")
aDate = cint(Request("selDate"))
aYear = cint(Request("selYear"))
Else
aMonth = UCase(MonthName(Month(Date()),true))
aDate = Day(DateAdd("d",-1,date()))
aYear = Year(Date())
End If
[code]....
Using JFrame In Java?
Apr 16, 2014how to use JFrames and button and so on in Java. I found this video on youtube and followed it along, however even though my program is virtually identical to his, I'm still getting errors.
Here's the video I was watching: Video
And here's my code:
import javax.swing.*; //Imports JFrame and JButton for use
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.*;
import java.awt.*;
import java.awt.event.*;
public class swing
[code]....
The reason why I'm importing some many things is I'm trying everything to try fix my problem.
He's the error messages I'm getting:
frame2.add(panel);
^
C:UsersWindows 8Documentsswing.java:42: error: illegal start of expression
frame2.add(panel);
[code]....
I used to make the button just create another frame without additional labels but I changed it to be even more similar to his program just to rule everything out. Also initially my program varied quite a bit, I've changed everything to be like his. Even without the ";" error I got, I kept telling me I was not allowed have my class as static, even though the guy in the video has it set to static. Also I don't think my "setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);" is working as it doesn't change color.
I think the problem is with my panel, it isn't adding to the frame for some reason.I'm using TextPad7 and I'm using Win8.
C:UsersWindows 8Documentsswing.java:42: error: '(' or '[' expected
frame2.add(panel);
^
C:UsersWindows 8Documentsswing.java:42: error: illegal start of expression
frame2.add(panel);
[code]....
I would also like to point out that some of the comments are out of date and are referencing the way the program was before I made it just like his. For example I know my second class isn't inheriting the first class.
How To Get All XML Branches Using JAVA
Apr 27, 2014How can I get all XML branches using JAVA. For example if i have the following XML:
<?xml version="1.0" encoding="UTF-8"?>
<addresses xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation='test.xsd'>
<address>
<name>Joe Tester</name>
<street>Baker street 5</street>
[Code] ....
The output will be :
addresses
addresses_address
addresses_address_name
addresses_address_street
addresses_person
addresses_person_name
addresses_person_age
Terminal Within Java GUI?
Sep 19, 2014I have developed a Java GUI by using Netbean. The user interface will get the user parameters that are needed by a c++ program (which I also developed). Upon clicking the run button java will execute the c++ program with the inserted parameters by launching and X-term session (using Runtime.getRuntime().exec(command) ) . Everything works fine in this way. However I do not find very elegant to launch an external terminal to run the C++ code. Is it possibile to have a terminal that is integrated within the java GUI? And run the C++ code within it?
Moreover, since the C++ code may take several hours to finish the job is there a way to read its output and use it in order to make, for example, proceed a progress bar?
Java To Access SAP
May 30, 2014Using java to access SAP? I want to create a UI to analyze SAP data and create JTable reports. Not finding much on the internet.
View Replies View RelatedComputing FFT In Java
May 7, 2015I'm trying to divide the array into two parts and then compute. And save the changes made in a global array f, The problem is the code does't work for the second call. The changes are overshadowed. How can I start computing and make necessary changes so that the calculation is retained?
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
[code]....