I am catching an error in my driver class that reads from a file and sorts the data based on a person's GPA. Here is my code:
import java.io.*;
import java.util.*;
public class Driver {
public static void main(String[] args) {
new Driver(args[0]);
[Code] ....
Why throwing this exception?
public class Person implements Comparable<Person> {
// the age of the person
private int age;
//the name of the person
private String name;
//the Integer object to wrap the age value;
private Integer ageWrap;
[Code] .....
The collection library has a class named TreeSet, which is an example of a sorted set. Elements in this set are kept in order. Carefully read the description of this class, and then write a class Person that can be inserted into a TreeSet, which will then sort the Person objects by age.
This is the exercise I am trying to solve. And this is as far as I have gotten to. Is it possible to sort my setOfPersons TreeSet directly? I tried to use
Collections.sort(setOfPersons)
method but it wont compile, and I realized that it is not applicable to TreeSet. So I made the
sortByAge()
method to do it indirectly...
I am puzzled though because in the exercise it states
write a class Person that can be inserted into a TreeSet, which will then sort the Person objects by age.
meaning that the TreeSet will sort the Person Objects and not my class..
i tried to run simple program od adding two number by using scanner class but there is run time error here it is code file and error.
View Replies View RelatedWhats the best way to implement an error catching sequence.I was developing a program to write to a . csv file. and this is one of the methods in it and how I thought Try/ Catch should be implemented. So I have three different possibilities. Another auxiliary class with some constants:
Java Code:
public class Constants {
/**
* Constant name of the file.
*/
public static final String fileName= "inventory.csv";
[code]....
I am creating a program where it reads the data inside a file and then places this data into arrays. The file I created has numbers 1-30 in it, file named, testing1.txt .
Java Code:
public static void main(String[] args) {
// TODO Auto-generated method stub
// Variables Declaration Section
//******************************
BufferedReader br;
String sCurrentLine;
String str;
[Code] ....
My issue is that the 'str' value is not initialized, but if I initialize it, it ruins the code. I'm not sure what to do in the situation.
I have created a jsp file which does the simple task of reading data from a mysql database and displaying the results on a web page. Please see below:
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
[Code] ....
However, each time I run the jsp file in the browser with my localhost as server, I get an HTTP Status 500 error.
For an assignment I need to read an input text file and evaluate the triangle based on the data found in the text file which consists of an unknown number of groups of 3 numbers (Each group representing a different triangle). According to the project specifications I need to have a main method and several other methods. I have the main method set-up to receive data correctly but I am confused as to how I would get the values out of the text file and use them in the main method. For example, if I were to call the computePerimeter method in my main method, how would I make sure I get the correct perimeter for the given data?
Here is the code I have so far:
import java.io.*;
import java.util.Scanner;
public class TriangleEvaluator
{
public static void main(String[] args) throws FileNotFoundException
{
Scanner in = new Scanner(new File("triangleData.txt"));
double s1;
double s2;
double s3;
while (in.hasNextDouble())
[Code] ....
I have a problem in reading the text file. I have my source text file at "D:/input.txt".When the below code is executed the following errors are coming.
" java.lang.NoClassDefFoundError: Try
Caused by: java.lang.ClassNotFoundException: Try
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
[Code] ....
I can read the data to a monitor perfectly. But, I'm having problem reading data from an external file into an array of class objects. Here's my attempt at writing the method:
private void openFile()
//This method asks the user to enter a file name(including the file extension) and then
//Sets the data to an array of Product type {
String fileName, storeName="", emptyLine1="", emptyLine2="", name="", productName="";
int demandRate=0;
double setupCost=0.0, unitCost=0.0, inventoryCost=0, sellingPrice=0;
Scanner inputStream = null;
[code]...
I am working on a project where as an input I need to read to data from PDF.
The PDF data will look like
As shown below:
Serial NoName of bookQuanity of BooksLibrary NamePrice
1aaa1London
2bb2Newyork
3cc1Paris
Total number of books4
Payment info
The number of books are dynamic in every pdf which I am going to receive.
I have to read data from a text file and print it in a new text file. An example of one line is like this:
Johnson 85 98 75 89 82
I then have to take the average of all the numbers and assign a "grade" to the numbers for each line of the text file and make a new file so it looks like this for 10 lines:
Name 1 2 3 4 5 Average Grade
Johnson 85 98 75 89 82 85.80 B
My problem is extracting the data from the file so I can use it.
Your Tester class main method must use an array or an ArrayList of Person objects. It must be populated from a text data file, friends_data.txt. Add the following data to your text file,
Michelle, 12/20/2008, Camilla
Bryan, 3/8/2007, Tom
Camilla, 6/7/2005, Michelle
Tom, 10/15/2007, Bryan
Charlotte, 3/2/2008, Michelle
Each line has the meaning:
-Person name, Person date of birth (MM/DD/YYYY), name of best friend
-Write a Java program that reads in the data from the friends_data.txt file, allocates a new
-Person for each and then stores the newly created object in either an Array or an ArrayList.
-Next print out a report showing the following information for each Person,
1. The Person's name
2. Their popularity counter
3. Their age on May 1, 2014
4. The name of their best friend
5. The age of their best friend on May 1, 2014
Finally, print the name of the most popular Person and the name of the oldest Person.
Person Class
import java.util.ArrayList;
public class Person {
public String personsName;
public String personsFriend;
public String personsBirthday;
public int personsPopularity;
public int popularity = 0;
[code]...
I keep getting this error from the compiler:
System.out.println("Popularity : " + personsOfInterest[i].getPopularityNumber());
"method getPopularityNumber in class Person cannot be applied to given type:
Required: java.lang.String[]; found: no arguments; reason: actual and formal argument lists differ in length.
I'm a complete beginner in Java programming and I'm interested to learn more about its concepts.
Recently, I've been given an exercise which instructs me to display two versions of a picture. The picture to be displayed is provided in the form of a data file of 40,000 digits that are arranged in rows (although there is no marker between rows) and it starts from the top of the picture. So the first digit represents the top left corner of the picture and the last is the bottom right.
Basically, what the exercise wants me to construct a program that plots a dot in one of two colours for each digit. If the digit is in the range 0 to 3 the output should be one colour and for digits in the range 4 to 9 the dot should be in the other colour.
I understand I have to use arrays and also loops to perform this. I'm familiar with the fillEllipse, drawEllipse, drawRectangle and fillRectangle but this exercise is nothing I've attempted before.
We have an autosys job running in our production on daily basis. It calls a shell script which in turn calls a java servlet. This servlet reads these files and inserts the data into two different tables and then does some processing. Java version is 1.6 & application server is WAS7 and database is oracel-11g.
We get several issues with this process like it takes time, goes out of memory etc etc. Below are the details of the way we have coded this process.
1. When we read the file using BufferedReader, do we really get a lot of strings created in the memory as returned by readLine() method of BufferedReader? These files contain 4-5Lacs of line. All the records are separated by newline character. Is there a better way to read files in java to achieve efficiency? I couldnt find any provided the fact that all the record lines in the file are of variable length.
2. When we insert the data then we are doing a batch process with statement/prepared statement. We are making one batch containing all the records of the file. Does it really matter to break the batch size to have better performance?
3. If the tables has no indexes defined nor any other constraints and all the columns are VARCHAR type, then which operation will be faster:- inserting a new row or updating an existing row based upon some matching condition?
I'm having a bit of trouble with using the Scanner and the Printwriter. I start with a file like this (1 = amount of Houses in the file)
1
FOR SALE:
Emmalaan 23
3051JC Rotterdam
7 rooms
buyprice 300000
energylevel C
The user gets (let's say for simplicity) 3 options:
1. Add a House to the file,
2. Get all Houses which fullfil requirements (price, FOR SALE / SOLD etc.) and
3. Close the application.
This is how I start:
Scanner sc = new Scanner (System.in);
while (!endLoop) {
System.out.println("Make a choice);
System.out.println("1) Add House");
System.out.println("2) Show Houses");
System.out.println("3) Exit");
int choice = sc.nextInt();
Then I have a switch for all of the three cases. I keep the scanner open, so Java can get the user input (house = for sale or sold, price = ... etc). If the user chose option 1, and all information needed is inputted and scanned, the House will be written to the file (which looks like what I typed above).
For this, I use try (PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("Makelaar.txt", false)))). This works perfectly (at least so it seems.)
If the user chose option 1, and all requirements are inputted and scanned, the Houses will be read (scanner) from the file and outputted. For this I use the same Scanner sc. This also works perfectly (so it seems atleast).
My problem is as follows: If a House has been added, I can only read the House(s) which were already in the file. Let's say I have added 2 houses, and there were from the start 3 houses. If option 2 is chosen, the first 3 houses will be scanned perfectly. An exception will be caught for the remaining 2 (just added) Houses. How can I solve this? I tried to close the Scanner, and reopening it, but apparently Java doesn't agree with this
I was asked to write code to calculate a person's calories burned/min. This is what I got. The problem is I keep getting an error.
--------------------Configuration: <Default>--------------------
C:Program FilesJavajdk1.7.0_72CaloriesBurned.java:22: error: possible loss of precision
caloriesBurnedPerMinute = 0.0175 * METS * weightInKg;
^
required: int
found: double
1 error
Loss of precision? What does that mean? Do I have to change weightInKg into some other number type?
import java.util.Scanner;
public class CaloriesBurned
{
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
int runningHours, basketballHours, sleepingHours, METS, caloriesBurnedPerMinute;
[Code] ....
public class Employee {
private String firstName;
private String eeid;
}
I want to sort using empoyee firstName.. If two employee names are same, i need to sort based on eeid.. using insertion sort
if (key == "name") {
for (int i = 1; i < list.length; i++) {
Employee t = list[i];
int j;
for (j = i - 1; j >= 0 && t.getLastName().compareTo(list[j].getLastName())<0; j--)
list[j + 1] = list[j];
list[j + 1] = t;
}
}
It will sort using names.. But if two names are same, it wont sort based on eeid.. I want to achieve only using insertion sort..
EX:
vivek 8
broody 2
chari 3
vivek 5
chari 1
output:
broody 2
chari 1
chari 3
vivek 5
vivek 8
The program should copy person with the highest percent from the file 'plik1', and then put it to the file 'plik2'.The problem occurs while compiling.
Java Code: string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type
string cannot be resolved to a type mh_sh_highlight_all('java'); Code:
[code]....
I'm new to programming and java and I'm trying to understand how exactly this piece of code works and what exactly does. I'm trying to make my first GUI application and to read some person details from a file and then put the result in a Jlist.
private static final String SEPARATOR = ",";
public static ArrayList<Speaker> getAllMembers() {
ArrayList<Member> members = new ArrayList<Member>();
try {
File file = new File(Resources.MEMBERS_TXT);
Scanner fileReader = new Scanner(file, "utf-8");
String[] properties;
[Code] ....
I'm using JSF1.2 and IBM websphere portal 7 (Core) not prime or rich faces. I would like to know to sort the JSF data table(<h:datatable /> using Jquery 1.7
View Replies View RelatedI have a very simple HTML form with a textField for a name, and add button to add the name to a MySQL database, and a sort button to sort the names in the database and display them. I almost have it working, however when I hit the "sort" button; I get the message that appears after a user clicks the add button along with the sorted list of names. It looks like this:
Please go back and add a name or sort.
Bill Jones
David G
Debbie Downer
Jane Doe
Joe Smith
John Doe
Mike Jones
Paul Smith
Susan Jones
What I have to change on my code to make just the list show up by itself when the user clicks sort?
My servlet code:
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
[Code] .....
Suppose i have written a method like this
public void myWork(){
mergeSortMyData(); O(nlgn)
....
someProcessing(); O(n^2)
someprocessing2(); O(n^2)
}
then what will be time complexity of my code...according to me it will be O(nlgn + n^2) ...is it correct ?
I have wriiten a quick sort algorithm. I have used the last element as my pivot. The program is running for all sizes except for 100000 and 1000000 elements when they are sorted and unsorted list .
It shows me the error : Exception in thread "main" java.lang.StackOverflowError
I guess the memory gets out of space and we need to increase the stack size in eclipse. How do I increase the stack size in eclipse.? I tried increasing through run--run configurations-- program arguments and typed---- -Xmx4096m but this didn't work in any way.
I need to take the users input from 2 boxes and reference that to a sqlite database and populate the fields with the data in the database. I know the database code work.
Here is the code for the "user" form;
Java Code:
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JTextField;
import java.awt.Font;
[Code] .....
So I'm trying to implement a quick sort method for an ArrayList of Strings and right now I'm getting the compiler error message: Exception in thread "main" java.lang.OutOfMemoryError: Java heap space. I don't know what that error means nor how to fix it. I've marked in my code where the error seems to be occurring.
import java.util.ArrayList;
public class quickSort
{
// constructor
public quickSort()
[code]....
i have a JTable with data that contains a column with Years.
I want to get the user to be able to sort the data between a range of two years.
Example:
a user sets te filter so he/she can view all the data between the years 1990 and 2000.
I am a beginner in Java and don't know how to code such a filter.
I guess it will be something with an if/Else statement or a loop?