I have to use a long primitive type for the input of a credit card number and ID the credit card by using the first number of the input; however, the only way I know for that is to use charAt, which is used for a String. Is there a way to convert long to String, or am I missing a better solution? (There's no code because I'm still doing the pseudocode).
View RepliesI have this code which suppose to sort files by their length and return a string[] of th file names:
import java.io.File;
import java.util.ArrayList;
public class SizeOrder extends SuperOrder {
public String[] sortArray(File[] pathList) {
File[] absoluteOrderFiles = this.absoluteSort(pathList);
ArrayList<File> sizeOrderList = new ArrayList<File>();
[code]...
Now, in the following line: absoluteOrderFiles[absoluteIndex].length() < sizeOrderList.get(sizeIndex).length()
I need to use the compareTo which only exists in Long object.
How do I convert primitive long to Long?
and is it possible to do it in a single line?
Currently, my program converts Long values to String. And when I test it out, it do print out the correct output. However, when the converted String value is passed over to be written in a text file, it seems that BufferedWriter isn't printing out the outcome that it's supposed to be.
saltVs = Long.toString(saltV);
System.out.print(saltVs); //will print out 79723172
Now the problem is here...It only prints out the last digit of the String value (instead of 79723172).
Here is my FileWriter/BufferedWriter part.
Why is that when I run my program using command prompt, it prints out the output that I wanted, but however when it comes to writing to the file, it doesn't come out right.
If you have final int i = 1;
short s = 1;
switch(s) {
case i: System.out.println(i);
}
it runs fine. Note that the switch expression is of type short (2 bytes) and the case constant is of type int (4 bytes).My question is: Is the type irrelevant as long as the value is within the boundaries of the type of the switch expression?I have the feeling that this is true since:
byte b = 127;
final int i = 127;
switch(b) {
case i: System.out.println(i);
}
This runs fine again, but if I change the literal assigned to i to 128, which is out of range for type byte, then the compiler complains.Is it true that in the first example the short variable and in the second example the byte variable (the switch expressions) are first implicitly converted to an int and then compared with the case constants?
I get an error when I try to divide 500 miles by 25.5 gallons
Exception in thread "main" java.lang.NumberFormatException: For input string: "25.5"
at java.lang.NumberFormatException.forInputString(Num berFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at Mileage.main(Mileage.java:42)
Java Result: 1
[Code] .....
I am totally new to Java. What is the purpose of this method?
Flow of the int x=3; like where does the 3 go step by step?
Passing Primitive Data Type Arguments (from oracle java tutorials)
Primitive arguments, such as an int or a double, are passed into methods by value. This means that any changes to the values of the parameters exist only within the scope of the method. When the method returns, the parameters are gone and any changes to them are lost. Here is an example:
public class PassPrimitiveByValue {
public static void main(String[] args) {
int x = 3;
// invoke passMethod() with
// x as argument
passMethod(x);
[Code] ....
I am currently working on modules of a java program but am having issues with this module . it gives this error code"syntax error on token '?', invalid primitive type".
This is my code:
import java.awt.*;
import java.awt.event.*;
import java.io.PrintStream;
import java.rmi.Naming;
import java.util.StringTokenizer;
[Code] .....
I have doubt in generics,
List<int> c=new ArrayList<int>();
why we cannot use primitive data type like int,double.
How can I store a value in long type variable whose range is greater than int type variable ....
View Replies View RelatedI have a code in which I am reading input from System.in and Destination is some where else
Here is my code
File file=new File("D:/output.txt");
OutputStream os=new java.io.FileOutputStream(file);
Scanner scanner=new Scanner(System.in);
System.out.println("Enter Data to write on File");
String text=scanner.nextLine();
int c=Integer.parseInt(text);
int a;
while((a=c.read())!=-1)
os.write(a);
System.out.println("File Written is Successful");
In the line while((a=c.read())!=-1)
a compile time error is shown "cannot invoke read on primitive data type int"
Where I am going wrong?
Is it possible to check to see if a what a user has entered is a string or a other variable type, if I'm asking this the right way?
View Replies View RelatedI am trying to override the equals method for my class TeamMember I have two fields:
private Details details;
private double salary;
Code for override I get an error on salary saying cannot invoke equals (double) on the primitive type (double)
Is their something I am missing/coding wrong?
Java Code:
public boolean equals(Object obj) {
//test exceptional cases
//avoid potential NullPointerException/ClassCastException
if ((obj == null) || (this.getClass() != obj.getClass()))
return false;
TeamMember other = (TeamMember) obj; //cast to a TeamMember object
// compare fields details and salary
return this.details.equals(other.details)
&& this.salary.equals(other.salary);
} mh_sh_highlight_all('java');
I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000
public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
System.out.println(i);
[Code] ....
I'm trying to write a condition to jstl if tag,
<c:forEach var="ledg" items="user_ledgers">
<c:if test="${ledg.transactionID == param['trns']}">
<c:out value="${ledg.name}"/>
</c:if>
</c:forEach>
Ledg is an object of ledger class and transactionID is a field of type long.
I found this error while runtime.
javax.el.PropertyNotFoundException: Property 'transactionID' not found on type java.lang.String
I tried to convert transactioID value to String by several ways. But not working.
String concatenation
<c:if test="${(ledg.transactionID+’’) == param['trns']}">
Using custom tag
<c:set var="equals" scope="page">
<z:doTheyEquals v1="${ledg.transactionID}" v2="${param['trns']}"/>
</c:set>
It also expects String type.
I'm trying to output a ten digit phone number as a string on one file, and write another program to write it as a long because I don't know what value I need to use in order to get the code to run properly on either one.
View Replies View RelatedI have created an application using hibernate and struts.In which a form is created where the user will enter all its personal details(for e.g name ,phone no. and address).
Here for address I have used textarea and whenever user enters the address, sometimes it can be a long string also.
So the problem is if a long string is entered then while displaying that ,address comes on single line and the page is stretched.
how to break this single string into mutiple lines in java class?
I have a String repersentaion of some Object.I want that object convert back into some class type how can I do this?
View Replies View RelatedI have this project due and its asking that i print out what type of triangle it is when the user inputs 3 sides. I have most of it done and working, but it pops up different windows instead of using one window for everything. The assignment says it needs all the final info to be in one window. The boolean is coming from another method. I'm unsure how to get it into a string (Or if that's what i have to do). The method must return a boolean true/false.
import javax.swing.*;
public class Triangle {
public static void main(String[] args) {
int side1 = getSides();
int side2 = getSides();
int side3 = getSides();
[Code] ....
In my Java class, the last assignment we had to turn in was to create a program that would take a users input and create a new type of animal. I went through the different steps in the instructions, and everything seemed to be going well up until the point where we actually took the users input and created the new animal. Specifically, I kept getting an error stating that I could convert a String to an animal.
I'm attaching the main class (Animal), one of my animal classes (Bird) and the class where I'm getting the error (AnimalStuff). I turned the program in as is, so what's done is done, but I'd like to learn what I'm doing wrong and what I can do better. I do know that the loop in AnimalStuff is wrong as it doesn't work right either, but I'm more concerned about the conversion from String to animal, as the entire program depended on this to work, and it doesn't.
public class Animal {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
}
public static String kind;
public static String integument;
[code]....
Is there anything that jumps out at to what I'm doing absolutely wrong?
I've started writing a new program that Scans for some strings. I want to specify a random Integer to those Strings in order to do my desired idea. what should I do?!! my codes are here :
import java.util.Random;
import java.util.Scanner;
public class Draw {
public static void main(String[] args) {
System.out.println("This Program is written to solve little problems in families cause of doing unwanted works!!");
[code].....
now I want to Specify an Integer to each person that has been scanned! for example if the first person is " David " , which is a String, in the next step :
Random randomNumber = new Random();
randomNumber.NextInt(101);
int David = randomNumber.NextInt(101);
I want to what should I do?
How can i convert date to string. Is this the best way
// Create an instance of SimpleDateFormat used for formatting
// the string representation of date (month/day/year)DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
// Get the date today using Calendar object.Date today = Calendar.getInstance().getTime();
// Using DateFormat format method we can create a string
// representation of a date with the defined format.String reportDate = df.format(today);
// Print what date is today!System.out.println("Report Date: " + reportDate);
I am converting String to date object while converting this i am getting Run time Exception. Here in this code i am using String tokennizer reading a data from a text file. Here is my code
public static void main(String[] args)throws Exception {
FileReader fr = new FileReader("g:abc.txt");
BufferedReader br = new BufferedReader(fr);
String line = br.readLine();
[Code] .....
here is an text file which i am reading
priyaRaoDBA13-APR-6002-JUN-92MahdipatnamHyderabad01-FEB-93 -AdminFpriyaM784223680212348
ArifRizwanDevelopment14-FEB-8812-MAR-12Sathya coloneyHyderabad10-FEB-14 -Software EngineerMasdfghManager7842655502123
AFifRizwanDevelopment14-FEB-8812-MAR-12Sathya coloneyHyderabad10-FEB-14 -Software EngineerMasdfghManager7802655502123
AsifRizwanDevelopment14-FEB-8812-MAR-12Sathya coloneyHyderabad10-FEB-14 -Software EngineerMasdfghManager7842631102123
I am obviously new to programming and Java so I set myself the goal of creating a very simple auto type style of program so it gets the users input and relays it out again but potentially to another window (I am currently testing to notepad). The reason I am trying to make it is because i thought it could be quite simple and I can build on it as a project to make it better.
The issue I am having is that it outputs the first character to the window I am selected (again testing into notepad) but then stops and doesn't output anything else. I tried to figure out what was going on by putting a System.out.println(arr[6]); after the delay method but it just output a line so almost like what I was putting into the array was only storing the first character of the string? I cannot figure out why that would be...
import java.awt.*;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.util.Scanner;
public class MyBot
public static void main(String[] args) throws AWTException {
//initialising robot
Robot r = new Robot();
Scanner input = new Scanner(System.in);
[code]....
I am supposed to write a program on PuTTY using UNIX (I have Windows 8), but I am not comfortable with it yet, so I am using Java through NetBeans (IDE 7.4).
The program has to follow these instructions (ignore the Linux part of the instructions, the rest is in bold):
Write a program on the Linux system using the putty utility. The program should get strings of data from the command line (that is, look for the data in the "args" array of strings). Use a loop to convert each of the strings in the array into a double and add the number to a total. Print the total after all of the strings have been processed.
The program will use try-catch to catch any error that occurs. If an error occurs, the program will print a message saying that the error occurred. The program can end at that point.
You should create the Java program using the nano editor. The input data should be a list of numbers on the line that runs the program.
The problem so far is that I keep getting an error when converting a String value into a new double value. I have yet to code the try-catch method in my program
Java Code:
import java.util.*;
public class Program13Strings {
public static void main(String[] args) {
Scanner scan = new Scanner (System.in);
System.out.println("How many lines of data do you wish to enter?");
int size = scan.nextInt();
[Code] ....
*NOTE: right where my code says double newDouble = Double.valueOf(newResponse); is where the error is occurring.
*ERROR: Exception in thread "main" java.lang.NumberFormatException: For input string: "abc"
at sun.misc.FloatingDecimal.readJavaFormatString(Floa tingDecimal.java:1241)
at java.lang.Double.valueOf(Double.java:504)
at program13strings.Program13Strings.main(Program13St rings.java:21)
Java Result: 1
How can this be fixed so I don't get this error?
I'm using the class below to encrypt and decrypt data in my program. It works rather well with the exception that I can't for the mind of me get the recreation of the key to work. When the program runs the first time, it creates a key and saves it to Data.txt. This part works fine, and there are no errors, the encryption and decryption works until I reload the program and it tries to recreate the key using the String in the .txt.
read = loadFile.readline();
byte[] data = read.getBytes("UTF-8");
key = new SecretKeySpec(data, 0, data.length, "PBEWithMD5AndDES");
I've looked at:
java - convert Byte Array to Secret Key - Stack Overflow
java - Converted secret key into bytes, how to convert it back to secrect key? - Stack Overflow
and a number of other sites which didn't work, both of these however suggested the key = new SecretKeySpec. The actual key became: "[B@79fe3f51". Whereas the recreated key became: "[B@3e1d1648".So they are close, but not the same.I create the original key like this:
key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
Encryption.java:
public class Encryption {
public Cipher dcipher, ecipher;
// Responsible for setting, initializing this object's encrypter and
// decrypter Chipher instances
Encryption(String passPhrase) {
[code]....
I'm stuck with the following error message when i try to convert a String to XML and back to a String.
Exception in thread "main" org.w3c.dom.DOMException: WRONG_DOCUMENT_ERR: A node is used in a different document than the one that created it.
at com.sun.org.apache.xerces.internal.dom.ParentNode.internalInsertBefore(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.ParentNode.insertBefore(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.NodeImpl.appendChild(Unknown Source)
at com.innovatrail.consulting.xml.XMLTEST2.main(XMLTEST2.java:66)
Below is my Java code snippet: The code syntactically correct except line 66. If you comment out line 66 in the source code, everything works just fine. The XML representation of my input string is denoted by INPUT 1 and that of my output string is denoted by OUTPUT 2.
package com.Test.xml;
import java.io.ByteArrayInputStream;
import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
[Code] ....
INPUT 1:
<Collection>
<BookList>
<Book>
<Title>Wonder Man
</Title>
<Author>John Smith
</Author>
<Category>Fiction
[Code] .....
OUTPUT 2:
<Collection>
<Book>
<Title>Wonder Man</Title>
<Author>John Smith</Author>
<Category>Fiction</Category>
[Code] ....