how to add an error message when my program can't find the file the user inputs.
For example:
Enter your source code:
D:Data StructsProjectssrcHelloWorld (I didn't put .java on purpose)
Exception in thread "main" java.io.FileNotFoundException: D:Data StructsProjectsAssignment 3srcHelloWorld (The system cannot find the path specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileReader.<init>(Unknown Source)
at HomeworkDriverFour.main(HomeworkDriverFour.java:14)
//Can I get rid of the exception above and replace it with "File not found!"
Enter your source code:This is what I have so far:
import java.io.*;
import java.util.*;
public class HomeworkDriverFour {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
I'm doing homework and as far as input, my assignment reads: "Your program must take as input the name of a Java source code file such as the source file containing the source code of this assignment." So my question is, how do i do that without linking the directory directly (i.e. C:/users/...)? I'm using FileReader as shown below...
public static void main(String[] args) throws Exception { FileReader file = new FileReader (WHAT GOES HERE???); BufferedReader reader = new BufferedReader(file); String s = ""; String line = reader.readLine();
This is a snippet code that im developing. (no source of it) . I am facing a trouble to extract file in the same directory as the source file (example: extract here option)
public class HelperAction { public static void unzip(String zipFilePath)throws IOException { File dir = new File(zipFilePath.substring(0,zipFilePath.length())); // create output directory if it doesn't exist if(!dir.exists()) dir.mkdirs(); FileInputStream fis;
I have a file(source.txt) that contains some texts. Now, the java code is to run through each line in the source file and check if that line begins with a number and if true, copy that line to the destination file(destination.txt). I have the code but I am not sure why I can't loop through each line in the source.txt file. Below is my java code:
public static void copyFile(File source, File destination) { BufferedReader br; try { FileWriter fw = new FileWriter(destination.getAbsoluteFile()); PrintWriter bw = new PrintWriter(fw); br = new BufferedReader(new FileReader(source)); String line = new String();
[Code] ....
As shown in the source.txt file, there are 4 lines in the file but when the execution gets to while ((line = br.readLine()) != null) , it executes to false.. Why this is so?
below is the source.txt file
12 is a number Green is bad 5 is not so cool you are right
Have the following .bat file that compiles the ReadMindWave.java source with jna and jfreechart. I get a javac error saying 'no source' when the .bat is run, as the .java source needs to be included in the .bat file. Where it goes in the following .bat file?
@echo off echo Compiling %1 with JNA and JFreeChart... javac -Xlint:deprecation -cp "C:jna-master*;C:jfreechart-1.0.19libjfreechart-1.0.19.jar;C:jfreechart-1.0.19libjcommon-1.0.23.jar;."%*
The file to compile is in C:MindWaveTestsReadMindWave.java
when i try to compile following source file, there is a error which states "MovieTestDrive is public, so must be declared in a file MovieTestDrive.java" i didnot understand. i am beginner in java;
class Movie { String title; String genre; int rating; void playit() { System.out.println("playing the movie"); } }
I am having hard time to grasp the concept of java as i am beginner. according to different sources found in internet, only one class is written in one source file. and all those class can be accessed through the main class. my question is
1.can we access one class present in one source file, through another class present in another source file [not through the class containing main method]?
2.can we create more than 1 class in same source file?is there special way to do it? i do get error always when i try to do so 3.can multiple classes contain main method? or should there be only single class containing it?
2) Specify what arithmetic operators to swap (+, -, /, *)
2) If an arithmetic operator is read (like a + sign etc) then we swap it with its opposite (- for example)
3) Once the swap is complete, the rest of the file stays the same even if more operators are in the file...it is then output to a file (I am going with 1mutation.java)
4) This is where it gets tricky....it then picks up where it left off to finish reading the + operators (or whatever was specified) and repeats steps 2-3 (but the operator that is already swapped gets left as it was / skipped) and the output is saved as 2mutation.java.
The most I have been able to manage is having it changed 1 operator or all of them at once. I deleted a lot of my work to start fresh / master one operator for the time being. Here is what I have:
This is the data file I am using. (see attached) The file should be .java or .cpp but I stuck with .txt for now. How to tackle this? Am I on the right track?
To compile this code(Something.java) from command line I want to use the following command,
javac org/apache/Something.class
And for the compilation to be successful, I'll have to be just above bin-folder because...
- > Only then my default class path will be (.) and java would automatically include A.jar and B.jar(the other way is to add the jar files using -cp argument, which I want to avoid in this scenario)
- > And for the import org.mycompanyX to work I'll have to be in the (.) directory.
Are my assumptions correct about how java find jar contents imported in a source file?
I have a question about the following snippet concerning the steps the javac compiler follows to compile a program:
[...]at first, searching a class within a package is discussed if the latter doesn't contain a full package name[...]
It is a compile-time error if more than one class is found. (Classes must be unique, so the order of the import statements doesn't matter.)
The compiler goes one step further. It looks at the source files to see if the source is newer than the class file. If so, the source file is recompiled automatically. Recall that you can import only public classes from other packages. A source file can only contain one public class, and the names of the file and the public class must match. Therefore, the compiler can easily locate source files for public classes.
However, you can import nonpublic classes from the current package. These classes may be defined in source files with different names. If you import a class from the current package, the compiler searches all source files of the current package to see which one defines the class. I don't quite understand the red fragment. I wondered if the word "import" nonpublic classes from the current package weren't a synonym for the word "use", since why would we want to import a class from the same package when compiler searches the current package automatically anyway?
However I wanted to test nonpublic classes that are contained in source file which name doesn't match the class name:
NonpublicClass.java:
Java Code:
package com.work.company; class NonpublicClass { public void description() { System.out.println("Working!"); } } mh_sh_highlight_all('java');
[Code] ....
Everything's fine when the source file names are the same as above. However, when I change NonpublicClass.java to a different name, there's an error "cannot find symbol" in:
Java Code: NonpublicClass v = new NonpublicClass(); mh_sh_highlight_all('java');
I noticed that the class file for NonpublicClass isn't even generated so that's probably the cause. If I change to the directory of the package the NonpublicClass is contained in and compile it directly, i.e. issue for example:
I am trying to complete this question. I understand the most of it but I haven't go a clue to read in the file name.
Full question: Implement a program that reads in a Java source code file and checks to see if it has balanced {}brackets. Your program should use a stack, implemented as a linked list, to check the brackets.
NOTE: you can use a reference called top which points to the head of the list. Your program should run as a command line program and should take a filename as an argument and print one of BALANCED or NOT BALANCED.
For example: c:> java checkBalanced "myProgram.java" BALANCED
So I was going to try to create a program that prompts input and creates a file (That didn't exist before) with that input as name.Then, the program prompts inputs after stating questions such as 1 + 1, then if the user inputs an answer, put "Question # = Correct "or" Wrong.Code SO Far:
Java Code:
import java.io.BufferedReader; import java.io.File; import java.io.InputStreamReader; public class File_Read { public File_Read() {//File_Read is the Interactive object
[code]....
So that it puts the Correct or Wrong into the file.
Exception in thread "main" java.lang.NullPointerException at javax.swing.ImageIcon.<init>(ImageIcon.java:205) at GUI.<init>(GUI.java:26) at Apples.main(Apples.java:7)
i think the problem is to do with my images not being recognised. I put them in my source in User>...>workspace>src which is correct as far as i know. From what i know the images should show up if i look at my src file in eclipse but they dont. I tried changing the file type from .png to .jpg but it makes no difference.
Well my code is supposed to ask for an input file and then (ex: input.txt), read the input file and create an output.txt file with the anagram for the words in the file. Also it should be displayed on the screen. However my code doesn't display the anagram on screen or the output file!
/* This program will read a file given by the user, read the words within the file and determine anagrams of the given words. If the file that the user inputs is empty, then the program will output "The input file is empty." * The program will read the file line by line, counting the total number of words read. If there are more than 50 words, "There are more than 50 words." * will be printed, and the program will terminate. After each line is read, the words in the line will be separated,punctuation characters will be removed, and upper case characters will be switched to lower case. * If any word is larger than 12 characters, that word will not be considered in the total amount of words in the file and it will not be sorted. * After each word is read, the letters will be sorted and stored into an array containing each * word's 'signature'. After all the words have been read, words will be printed to the output file on the same line based upon their signature. */
public class Anagram { //Creating constants for maximum words in file and maximum chars in word public static final int MAX_CHARS = 12; public static final int MAX_WORDS = 50;
I am trying to read a file and input each line of the file into an array. I have not set the array size as I was hoping to fill the array using a while loop. Unfortunately the scope of the array does to work inside the while loop so I am being told that the array 'students' has not been initialised even though it has just outside of the while loop. Is it possible to do what I am trying to without having the array initialised in the while loop as surely the array will be reset every time if it was in the while loop? Here is my code:
public static void students(String file) throws FileNotFoundException { try { File studentInfo = new File(file); Scanner input = new Scanner(studentInfo); String[] students;
So my assignment is to read these values from an input file which I previously created. The 10 values represent miles traveled and I convert them using some formula my prof gave me to get the total cost, and output both values to an output file.
My programming question is the first number on the input file isnt a mileage value its the number 10, which is the number of values to be processed, which we're supposed to use in order to control a for or while loop which we'll use to process the contents of the input file. How would I create a while or for loop and get it to skip the first value of the input file?
We're not allowed to use arrays for this assignment.
Also here's my code so far, and it says its not being able to find the file, I made sure the file name is exactly as saved, and its saved in the same directory as the java class that i created for this assignment so I don't see what the problem could be?
Here's my the class with the main method
import java.util.*; import java.io.*; public class QudratullahMommandi_3_07 { public static void main (String[]args)
QudratullahMommandi_3_07.java:17: error: unreported exception FileNotFoundException; must be caught or declared to be thrown Scanner input = new Scanner(inputSource); ^ 1 error
----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
how I can change my code so that somebody can actually input the specified file path, rather than having it fixed in the code. I previously used
Scanner in = new Scanner(System.in); System.out.println("What is the filename?"); String input = in.nextLine(); File file = new File(input);
But then the program would not display the frequencies.
import java.io.File; import java.util.*; /* This program will allow the user to enter in a text file name, when prompted the program will anaylser the text and display the frequencies */ public class AssP { public static void main(String[] args ) { Scanner scan; try { Scanner scanner = scan = new Scanner(new File("C:/Users/Mary/workspace/Assingment/src/test.txt"));
[code]....
This is my current code and I need to so the user can load their own files.
This is my input from my text file: 1|John Jay Smith|1985-01-10|2010-05-10|2014-03-05|212-222-2233..So, I have to convert 1 to integer. Break John Smith into first name as John and Middle name as Jay Last name as Smith.If no middle name is given then first is John and Last is Smith . Read 1985-01-10 as a date value . 2010-05-10 as another date value which could be null. 2014-03-05 as another date value which could be null. and at last 212-222-2233 as phone number.
Scanner sc = new Scanner (inFile); sc.nextLine(); while (sc.hasNext()){
String row= sc.nextLine();
I want to read this line of input and assign the value accordingly.
Is there anyway to format my input file "IF1.txt" into an excel/csv file, but with the content rearranged into a desired format? (all of this has to be done by a java program)
I'm having some kind of weird problem reading input from a file. It says that my scanner object I'm using to hold an item of information isn't initialized, when I do try to initialize it, it says error variable already initialized. I'm using the scanner to read input from a file whose contents are this
import java.util.*; import java.io.*; public class QudratullahMommandi_3_07 { Toolkit_General toolKit = new Toolkit_General(); public static void main (String[]args)throws IOException
[Code] .....
This is the error message
QudratullahMommandi_3_07.java:34: error: variable holder2 might not have been initialized String holder2 = holder2.trim(); ^ 1 error
----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
i dont know how to write main that would open the input file and read using this method...
[/package AssignmentSeven; import java.io.*; import java.util.Scanner; public class Assignment7 { public static void Towers(int nTowers, int fromTower1, int workTower2, int toTower3) { if(nTowers == 1)
