Though have been playing around with my ebook but finding it difficult to get along with the topic PACKAGE&INTERFACES, I find it challenging to write a package file despite the book I currently studying and online tutorial.. so I want a more explanatory format to comprehend the piece cos without knowing it.
View RepliesMy working directory is e:ajava. in package p1 i create two classes c1 and c2. net beans creates three files e:ajavap1srcp1, e:ajavap1srcc1, e:ajavap1srcc2. package runs without a hitch. i create another package p2 under e:ajava. i want to use class c1 in p2. pray what on earth should be my import statement in the p2 source code after the first statement 'package p2'. another related querry what should i include in my class path so as to gain access to c1 and c2 in source code of p2.
View Replies View RelatedI'm trying to access class file which is inside the package and package is inside the jar file but I can't access that class file inside my source file . All files are on desktop .
View Replies View RelatedOut of eg. MyApp.java in the directory est I can create the MyApp.class by way of this order:
Java Code: javac C: estMyApp.java mh_sh_highlight_all('java');
It should be possible to let the javac create a subdirectory according to the file's package statement. So I have tried:
Java Code:
javac -d C: estMyApp.java mh_sh_highlight_all('java');
That always gives me the message that javac could not create the directory.
Let's say hypothetically you're making a huge program and use a lot of imports (ex import java.util). If you only need a few specific things from java.util, will it use more memory importing java.util.* compared to only importing lets say java.util.Scanner, java.util.ArrayList, etc. Basically does importing a whole package use more (if any at all) memory than only importing specific package parts?
View Replies View RelatedI am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product
{
public String pName;
public String stringName;
public double price;
public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product
{
public String pName;
public String stringName;
public double price;
public int quanity;
//Constructor
public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
I am new to java and I am creating a system that will ask the user to create a file that will store to a text file, Once the user created the file I have a class that will let the user input the subject name that has been created, However, I keep on getting this java.util.nosuchelementexception.Here's my code:
public void display_by_name()
{
String id, name,total;
String key[]=new String[30];
String value[]=new String[30];
int i=0;
[code]....
I need to write a program that will create an inventory file as a random access file. The problem that I am having is that among the things I need to add to the random access file is a "car name". Since random access files are byte based I don't know how I could possibly write and then read a string value.
View Replies View RelatedI'm having a problem with using the openCSV library when I create a JAR file. I'm currently using BlueJ to run my code. When I compile my program in there, I have no problems whatsoever and it runs great, yet when I create my program into a JAR file, my application doesn't work.
I would think that my problem is either stemming from faulty exception handling, although I don't understand why an input would work in the BlueJ environment, but not when using the JAR file. Or, perhaps the openCSV library isn't in a correct class path(I don't know if this is correct terminology).
It is possible to delay the creation of a file until I know I am writing to it.
View Replies View RelatedI am working on a java logic game and I want it to be able to work on other people's Mac's, so I tried to figure out how to make it create a folder in which it can create files. The file creating is going fine however the folder never seems to create.Here is the code I attempted to use:
File logicFile = new File("/Library/Application Support/LogicGameSupport");
if(!logicFile.exists()){
if(logicFile.mkdir()){
System.out.println("Directory success");
}else{
System.out.println("Directory failed");
}
}
I'm getting a DOMException, "HIERARCHY_REQUEST_ERR". I know that the problem is from the following code towards the bottom in my function, but I don't know how to deal with it. When I get rid of doc.appendChild(staff);, I get rid of the problem, but it obviously doesn't add the new entry to my root element.
Element staff = doc.createElement("Staff");
doc.appendChild(staff);
import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
[Code] .....
import java.io.*;
public class ReadNumbers
{
void input()
{
String File_name = "num.txt";
File numbers = new File(File_name);
[code]....
I am using eclipse and I went to file, add new file and named it num.txt:shot.png like show in the picture.
I currently finding a way how can i package a required/dependency JAR with my runnable JAR only using a command prompt like :
how the ECLIPSE IDE export RUNNABLE JAR
I am running on a linux environment, is there a way to do this.
I can only make Runnable Jar without the required JAR by using this command
jar cvfm Test.jar manifest.txt package/*.class
I want to create hidden files, some sample code for doing this.
View Replies View RelatedI need to check an existence of a file if it is already created or not but the problem is on my code I obviously making the file first before I am able to check if it exist or not.
File createFile = new File ("//path/name.txt");
I've read somewhere that that line should not make a file without the createFile.createNewFile(); but when I tested it and on my program, my program was creating the file even without the .createNewFile() method with that said. I'm confused on how would I be able to check an existence of a file without of course having it pre-created. here is the partial code:
File newFile = new File ("C:/Documents and Settings/Admin/Desktop/Keys.txt");
BufferedWriter write = new BufferedWriter (new FileWriter (newFile));
BufferedReader read = new BufferedReader (new FileReader (newFile));
if (newFile.exist())
{
System.out.print("File is existing");
}
There are several ways in Java to create a text file and write to it. But which is the most effective way among them? Any example with code?
View Replies View RelatedI'm trying to copy my program output to a text file and still have it be displayed in the console.
View Replies View RelatedFile dir = new File("file"); //creates folder named file
File dir1 = new File("file.txt"); //creates file
But I want to take in a file name from user e.g.
BufferedReader br = new BufferedReader(is);
String filename = br.readLine( );
File dir = new File(filename + ".txt");
its expecting a string literal is there a way round it to take a string???
I'm currently working on a java project simply to learn java. So far, it creates a window and makes a properties file, or appends data to it if it already exists. The problem is that I'm not quite sure how to check if the file already exists to append data to it. I'm currently using a boolean (configCreated) that appends data when true, and creates a file when false. The problem is that this boolean is always false since it's at the beginning.
Java Code:
package Setup;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Properties;
[code]...
I'm trying to have the program create a .txt file for me but it is not working properly. It just keeps printing the exception error "The file could not be found" and exits the program.
// This program asks the user for input for a name, phone number and notes up to 200 entries.
// It stores every contact in a file. Type 'h' for help while running this program.
import java.util.Scanner;
import java.io.*;
public class Phonebook {
static Entry[] entryList = new Entry[200];
static int numEntries;
public static void main(String[] args) {
[Code] ....
After running the code, I go into my workspace folder and I see that the file was created. What to do because running the program will always print "could not find the file".
Instructions
Create a WordCounter class with a constructor that takes a file name as a parameter
The class should have two fields: one for the file name and one for a HashMap to store word count information
The constructor should call a private method, countWords, that reads in the file and counts the word frequencies
The class should contain a get method for each field, as well as a print method that prints out the map in the following format:word:frequency
When printing, the map should be sorted by either the word order or frequency (Hint: see Collections.sort)
You should include the sample text file on Blackboard. This is what i got so far
Java Code:
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Scanner;
public class WordCounter
[Code] ....
i want to list files from resources folder like this:
@ManagedBean
public class galley implements Serializable {
private List<String> list;
@PostConstruct
public void init() {
list = new ArrayList<String>();
[Code] ....
but it give me a null pointer exception on fList .... The directory of resources is :
How is this caused and how can I solve it?
my new class had me download eclipse and for some reason it won't let me type anything until I create a document. creating a document creates a package and that lets me create a class which then it will let me start typing code...so wtf is wrong with eclipse and why is it bulling me into having this "package" line in my code when I never had anything like that in other ide's?
View Replies View RelatedI have a folder of classes that I am packaging together. Some classes are being packaged and compiling just fine. My other classes in the same package, however, are saying that they cannot find these classes.
View Replies View Related