I have attached a picture. I am struggling to understand one of the errors. It says it requires an int and a string. I have put a number in but I don't understand the string part!
View RepliesIm trying to do this
if( 2/2 ) {
system.out.println( "number is not event" );
} else {
system.out.println( "number is event" );
}
However if statement requires a return of type boolean. So im forced to this instead
if( (2/2) != 0 ) {
system.out.println( "number is not event" );
} else {
system.out.println( "number is event" );
}
Is there a way to achieve the former method, without typecasting, if you had to typecast how do you do it?
I am doing a homework assignment and I am clueless as to what I did wrong or supposed to do in terms of placement of coding. If someone could dumb down their response and tell me what I did wrong
This is what I supposed to do:
1.) Type the following shell for the class:
public class ParadiseInfo
{
}
2.) Between curly braces of the class, indent a few spaces and create the shell for the main() method:
public static void main(String[] args)
{
}
3.) Between the braces of the main()Method, insert a call to the displayInfo() method:
displayInfo();
4.) Place the displayInfo() method outside of the main() method, just before the closing curly brace for the ParadiseInfo class:
public static void displayInfo()
{
system.out.println ("Paradise Day Spa wants to pamper you.");
system.out.println ("We will make you look good.");
}
This is what I attempted to do: I know it is wrong I am just clueless on where to put the code and why
public class ParadiseInfo
{
displayInfo();
public static void main(String[] args)
{
public static void displayInfo();
}
system.out.println("Paradise Day Spa wants to pamper you.");
system.out.println("We will make you look good.");
}
--- Update ---
I have also tried this:
public class ParadiseInfo
{
displayInfo();
public static void main(String[] args)
{
}
public static void displayInfo();
{
[Code]...
The very last attempt I only ended up with one error which is:
G:ParadiseInfo.java:3: error: invalid method declaration; return type required
displayInfo();
^
1 error
Tool completed with exit code 1
Java is very new to me and I have no clue on what I am doing wrong.
I'm trying to export a runnable jar file that requires lwjgl. Everything works in eclipse as I'm using
-Djava.library.path=nativewindows
as a VM Argument for the jinput .dll files.
After exporting & launching the jar it doesn't work of course! I get this error:
java.lang.UnsatisfiedLinkError: no junput-dx8 in java.library.path
I'm not sure how to make it work outside of eclipse....
I want to make several classes which extend different objects and add additional functions to simplify them and make their purpose in my projects more narrow and make their instances easier to use. So an example, Image class which extends BufferedImage and the constructor in Image class directly loads the file without having to create it first and then have to use Try Catch and all that additional code. Now, here is where my question comes in. Can I make an class, an abstract class or something which can be IMPLEMENTED into these several classes such as the Image class, and in doing so those several classes will have to have (like unimplemented methods) a HashMap<String key, ChildClass instance_as_value>, child class being the Image class as an example.
So I would have something like public class Image extends BufferedImage implements Library, and this class, because it implements Library will have a HashMap<String key, Image value> in it or it's parent class.
I am doing an assignment and I am clueless as to what I did wrong or supposed to do in terms of placement of coding.
This is what I supposed to do:
1.) Type the following shell for the class:
public class ParadiseInfo
{
}
2.) Between curly braces of the class, indent a few spaces and create the shell for the main() method:
public static void main(String[] args)
{
}
3.) Between the braces of the main()Method, insert a call to the displayInfo() method:
displayInfo();
4.) Place the displayInfo() method outside of the main() method, just before the closing curly brace for the ParadiseInfo class:
public static void displayInfo()
{
system.out.println ("Paradise Day Spa wants to pamper you.");
system.out.println ("We will make you look good.");
}
This is what I attempted to do:
I know it is wrong I am just clueless on where to put the code and why
public class ParadiseInfo
{
displayInfo();
public static void main(String[] args)
{
public static void displayInfo();
}
system.out.println("Paradise Day Spa wants to pamper you.");
system.out.println("We will make you look good.");
}
--- Update ---
I also tried it this one and ended up with 1 error..
public class ParadiseInfo
{
displayInfo();
public static void main(String[] args)
{
}
public static void displayInfo();
{
system.out.println("Paradise Day Spa wants to pamper you.");
system.out.println("We will make you look good.");
}
}
I have a JFrame with a button called "Start". The code behind the "Start" button triggers a function (startwork() ) that traverses through log files and then inserts rows into my JTable. If I call the startwork() function from the Start button action performed event, then when it inserts the rows to the JTable it is not immediately shown...
The code has to finish before the JTable is refreshed. However, if I run the startwork() function as soon as the JFrame is displayed (from the main() function) then I can see the Jtable being populated dynamically as it is inserting the rows.
How to allow the user to click on the START button and yet behave correctly to where the JTable is updated properly so that I can see the rows being inserted as it progresses.
I have a superclass used for all the other entity
@MappedSuperclass
public abstract class BssStandardEntityLaravel extends BssStandardEntity
implements InterfacciaBssStandardEntity, Cloneable{
private static final long serialVersionUID = 1L;
@Column(name = "created_at", nullable=true)
@Temporal(TemporalType.TIMESTAMP)
protected Date created_at = new Date();
[Code] ....
When i try to read some data with a JPA controller, this error is raised:
Persistent class "com.bss.libbssabstract.database.entity.BssStandardEntityLaravel" has no table in the database, but the operation requires it. Please check the specification of the MetaData for this class.
org.datanucleus.store.rdbms.exceptions.NoTableManagedException: Persistent class "com.bss.libbssabstract.database.entity.BssStandardEntityLaravel" has no table in the database, but the operation requires it. Please check the specification of the MetaData for this class.
at org.datanucleus.store.rdbms.RDBMSStoreManager.getDatastoreClass(RDBMSStoreManager.java:702)
[Code] ....
It requires BssStandardEntityLaravel table like a normal entity. I used the same entity package in other applications and it works perfectly. Why this error is raised?
I use jpa2.1.0 and datanucleus to enhance classes
How can I write a method that takes a string with duplicates letters and returns the same string which does not contain duplicates. For example, if you pass it radar, it will return rad. Also i would like to know how can I Write a method that takes as parameters the secret word and the good guesses and returns a string that is the secretword but has dashes in the places where the player has not yet guessed that letter. For example, if the secret word is radar and the player has already guessed the good guesses letters r and d, the method will return r-d-r.
View Replies View RelatedI am currently trying to make a calculator in Java. I want to use the String split method to tokenize the string of characters inputted. I thought I was using the String split method wrongly, because I had surrounded the characters I wanted to delimit with square brackets. However, when I removed the square brackets, the code threw an exception when I pressed the equal button. The exception was a PatternSyntaxException exception. Am I using the String split method wrongly? And why is the exception thrown? Here is my code:
import javax.swing.*;//import the packages needed for gui
import java.awt.*;
import java.awt.event.*;
import java.util.Arrays;
import java.util.List;
import static java.lang.Math.*;
public class CalculatorCopy {
public static void main(String[] args) {
[Code] .....
i am trying to write a class method which will take in a string and returns a string which is the reversed version of that string. it compiles fine but when i try to run it it states Main method not found in class StringReverse,please define the main method as public static void main(String[]args). I am new to java and cannot figure out
import javax.swing.JOptionPane;
public class StringReverse {
public String reverseString(String str){
JOptionPane.showInputDialog(null,"Please enter word");
char c = str.charAt(str.length()-1);
if(str.length() == 1) return Character.toString(c);
return c + reverseString(str.substring(0,str.length()-1));}}
I'm having trouble with the last few lines of the code. It's supposed to take a replacement string entered by the user and print out the new string. For some reason it's now allowing me to enter a replacement string
import java.util.Scanner;
public class Project02 {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.print("Enter a long string: ");
String lString = keyboard.nextLine();
[Code] ....
Output:
Enter a long string: the quick brown fox jumped over the lazy dog
Enter a substring: jumped
Length of your string: 44
Length of your substring: 6
Starting position of your substring in string: 20
String before your substring: the quick brown fox
String after your substring: over the lazy dog
Enter a position between 0 and 43: 18
The character at position 18 is x
Enter a replacement string: Your new string is: the quick brown fox over the lazy dog <------ isn't taking user input
I have a method for a button so when a user inputs something it then will get the string value and check it against the string value within the properties file to see if it exists.
The properties file is called GitCommands.properties that contains -- > key = value <-- in it
I realised I have not used it correctly hence why I keep getting errors - I am lost on how to use it, I think perhaps that may be the issue here? I need to reference the file but I am doing it wrong? When I do use that piece of code I get null pointer exception too...
textFieldSearch.getText().equals(GitCommands.keys());
This is my button:
JButton btnSearch = new JButton("Search");
btnSearch.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
FindSelectedKey();
[code] .....
I understand I am missing my piece of code where it states "//determine whether the string is equal to the property file key string" I understand the logic fine but not actually coding it.
I am trying to split a string based on length(example length 5) of the string. But I am having a issues with this substring(start, end) method. I get all substring which are of length 5. But if the last substring is less than 5 then I am not getting that last substring. But I need the last substring even if it is less than 5.
String s = "fjdjfdfjgffgjhfjghfjkhjhjh";
String spLine;
for(int i=0; i<s.length(); i=i+5){
spLine = s.substring(i, (5+i));
}
>
Code a Java method that accepts a String array and a String. The method should return true if the string can be found as an element of the array and false otherwise. Test your method by calling it from the main method which supplies its two parameters (no user input required). Use an array initialiser list to initialise the array you pass. Test thoroughly.
public class test {
public static void main(String[] args) {
Printhelloworld();
String[] verbs = {"go", "do", "some", "homework"};
printArrays(verbs);
[Code] .....
I'm having trouble to compare two string from my LinkedList. I took me 2 days now trying figure out how to compare the current string to previous string in the linkedlist. Here is my code.
public int compareTo(LinkedListNode n){
//Compare two string
String myHead = data.toLowerCase();
String comparableHead = data.toLowerCase();
return (myHead.compareTo(comparableHead));
}
How do I compare a String to each element of a string array?
For example:
int headscount = 0;
if (coins[i].equals("heads")){
headscount++;
System.out.println("b" + headscount);
}
This doesn't give me the right value because the IDE says that equals() is an incompatible type. I also tried changing the "heads" to an variable, but the results remains the same.
I would prefer using an Array!
So I'm creating a class which when given three inputs uses them as sides of a triangle and tells ther user what type of triangle it is, or if the input is invalid, tells them why it is invalid. I'm readin the input as a string and then trying to split it into a string array, from there checking to see if it has 3 elements.. in which the data is good at that point, and then converting them to ints and checking to see if they're negative ansd finally checking to see if they can work as sides of a triangle ie a+b >c, a+c >b , b+c >a.
I'm trying to split it into an array of strings but am getting an error, and can't seem to figure out why as this should be working from what I've read of the string.split method online.
import java.util.*;
public class TriangleTest{
private int sideA;
private int sideB;
private int sideC;
public static void main(String[] args){
TriangleTest triangle = new TriangleTest("3 4 5");
[Code] ....
The output reads [Ljava.lang.String;@15db9742
I've a problem in encoding a URL string.
I know to encode a string we use,
URLEncoder.encode(stringname,"UTF-8");
But when I use this I'm getting an error telling that the encode method will accept only 1 String argument.
I have a string value returned from a background tool that will range from 0 to possibly terabytes as a full number. I want to format that number to use commas and to reduce the character count using an appropriate size modifier (KiB, MiB, GiB, etc). I've tried converting the string number to a Double value using Double.parseDouble() and then performing the math based on the size of the value with this code:
Double dblConversionSize;
String stCinvertedSize;
dblConversionSize = Double.parseDouble(theValue);
if (dblConversionSize > (1024 * 1024 * 1024))
stConvertedSize = String.format("%,.000d", dblConversionSize / 1024 / 1024 / 1024) + " TiB";
...
I've also tried using
String.valueOf(dblConversionSize / 1024 / 1024 / 1024) + " TiB";
However, the formatting is failing and I'm either getting a format exception or the result is displayed as a number with no decimal component.
I have errors in the "if" and both "else if" ... The compiler says "cannot convert from String to boolean and int to String ...
instructions:
1. Add two private instance variables, String courseName and char grade to this class.
2. Add accessor and mutator methods for these instance variables.
3. Add a method register which receives an integer data type and returns String data type according to the argument passed to it ("Math" for 1, "English" for 2, "No course" for any other input)
What I have so far:
package assignment9;
public class BannerUser
{
private int userId;
public int getUserId()
{
return this.userId;
}
public void setUserId(int userId)
[Code] ......
I have the the string value similar to the one which i have to split based on the delimited ","
String SampleString=" 'ab,c', 'xyz', lm,n,o "
I know I can easily call split function which will eventually split the above string. But in my case the delimiter "," , is also a part of the string. If I call the function SampleString.split(',') I will get the output as listed below
ab
c
xyz
lm
n
o
but the expected output is
abc
xyz
lmno
I'm having a hard time with this problem, this is what I have, but I can not use two integers, I have to use one integer and a string...
This is the question:
Write a method called printStrings that accepts a String and a number of repetitions as parameters and prints that String the given number of times. For example, the call:
printStrings("abc", 5);
will print the following output: abcabcabcabcabc
This is what I attempted:
public class printStringsproject {
public static void printStrings(int abc, int number) {
for (int i = 1; i <= number; i++) {
System.out.print("abc");
}
}
public static void main(String[] args) {
printStrings(1, 5);
}
}
What is the difference between string and String (note the case)
View Replies View RelatedAnyways, variable names I have gotten from the code I've gotten from Minecraft using MinecraftCoderPack & Eclipse.
So... I have a string that I am wanting to get a number from.
Example:
public static final String[] exampleLetters = new String[] {"a", "b", "c", "d", "e", "f", "g"};
And, using a public Int (with no variables in the title), I am looking to take numbers for each string letter, to be able to output the value to other code.
Example:
public int letterConversion()
a = 0, b = 1, and so on to g = 6
How would I be able to get the numerical values of each letters using a public Int without any variables in the title?
Actual Code I have right now. Again, please ignore variable names, it's what I got use to while learning.
/** The list of the types of step blocks. */
public static final String[] slabType = new String[] {"stone", "sand", "cobble", "brick", "smoothStoneBrick", "netherBrick", "quartz"};
}
/**This checks slabType for the material and registers a number to each type for other codes to use.*/
public int textureType()
[Code] ....
For what I have now, in the Int...
for ( int var2 = 0 ; var2 < slabType.length ; var2++ )
Is controlling the output. No mater what the 0 is the output...
I'm trying to work out how to get a string from a servlet in to the JSP, The code I thought would work was as follows.
request.getSession().setAttribute("test", "this is a test");
request.getRequestDispatcher("C:myjsp.jsp").forward(request, response);
<%
String s1 = (String) session.getAttribute("test");
%>
<%= s1 %>
This is returning null ...
I have tried a few examples and followed a few tutorials but I keep getting null or nullpointexceptions.