I have Java code that iterates through files in a directory like this:
for (File child : dir.listFiles()) {
}
Inside that for loop I want to put the filename into a HashMap like this: autocompleteMap.put((String)child,itemList);
The java compiler doesn't like my cast attempt: "Cannot cast from File to String".How do I convert the filename into a String to put into my hash?
I'm actually trying to complete the excersise of the Servlets and JSP book in page 303 but I'm getting the following error in Eclipse Cannot cast from String to ArrayList(JSP).Here is the code
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ page import="java.util.*" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Hobbies Sharing</title>
</head>
[code]...
The error as it appears in line <% ArrayList al = (ArrayList)request.getParameter("Names"); %>
JAVA CODE:
package gui.dialog;
import cli.data001;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Vector;
[Code] ....
OUTPUT:
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean
at javax.swing.plaf.synth.SynthTableUI$SynthBooleanTa bleCellRenderer.getTableCellRendererComponent(Synt hTableUI.java:731)
at javax.swing.JTable.prepareRenderer(JTable.java:573 1)
at javax.swing.plaf.synth.SynthTableUI.paintCell(Synt hTableUI.java:684)
[Code] ....
I'm trying to write a condition to jstl if tag,
<c:forEach var="ledg" items="user_ledgers">
<c:if test="${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 am working on a program where I want the user to input multiple classes.
One int, and one String.
Can this be done? if so, how?
I have a tried to get input from both, like in the code below:
Java Code:
import java.util.Scanner;
public class ForumFlowchart {
public static void main(String[]args){
//Creating scanner.
Scanner input = new Scanner(System.in);
//Get information about job
System.out.println("Type in Int");
int i1 = input.nextInt();
[Code] ....
If I keep my input in the same class, I get the error "Can not cast int to string". My question is, it is possible to get an input from both an Int and a String in the same program?
Im trying to loop through a hashmap of objects. They are defined as People objects. People has two subclasses , Instructor and Student. As I am looping through the map of People, I am searching for class Instructor. If I find it, I want to access its method getDepartment in a println by casting to Instructor. When I do I get a runtime error:
Exception in thread "main" java.lang.ClassCastException: java.util.HashMap$Node cannot be cast to uStaff.Instructor
at uStaff.PersonApp.menu(PersonApp.java:108)
at uStaff.PersonApp.main(PersonApp.java:21)
//Instantiate the different Person, student and instructor objects
Person thisPerson = new Person(01,fName,mName,lName,email,ssn,age);
Student thisStudent = new Student(02,"Stacey","Marie","Morgan","smorgan@gmail.com","213-45-6789",20);
thisStudent.setMajor("music");
Instructor thisInstructor = new Instructor(03,"Joe","Douglass","Wells","joe@drumhaven.com","555-98-3029",46);
thisInstructor.setDepartment("Computer Science");
[code]....
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine engine = mgr.getEngineByName("js");
String expres = calc.getText().toString();
calc.setText(expres);
try {
calc.setText(((double)engine.eval(expres)) + "");
} catch (Exception e) {
}
This line: calc.setText(((double)engine.eval(expres)) + "");
*The error message for this line: Cannot cast from object to Double
I ve got a 2d array and I want to cast it in an 2d arraylist. I ve create a function that cast an array to arraylist. My problem arises, when I tried to parse the whole 2d matrix to the arraylist. I use the following code:
Java Code: double sums[][] = computeSums(lab, projections);
ArrayList<ArrayList<Double>> lists = new ArrayList<ArrayList<Double>>();
ArrayList<Double> nu = new ArrayList<Double>();
System.out.println(sums[0].length);
for (int i = 0; i < sums.length; i++) {
ArrayList<Double> tt = toList(sums[i], nu);
lists.add(tt);
} mh_sh_highlight_all('java');
The problem is that only the first matrix sums[0] is copied to the 2d arraylist sums.length times. How is is possible to store all the different sums matrices to the arraylist??
When does an internal cast actually happen? I am aware that compound assignment operator do an internal cast. Does it happen in Assignment 1?Assignment 2?Assignment 3?Assignment 4?
Java Code:
public class Parser{
public static void main( String[] args){
byte b=1;
short s=1;
int i=1;
s=b;//Assignment 1
s<<=b;//Assignment 2
b<<=s;//Assignment 3
s +=i;//Assignment 4
}
} mh_sh_highlight_all('java');
import java.util.ArrayList;
public class Demo {
class Expr {}
abstract class Factory <T extends Expr> {
abstract T generate();
[Code] ....
Doesn't Factory2 produce Statements?
the output of this:
int x = (int) 24.6;
I want to write formatted output on a notepad file using ObjectOutputStream but I am not getting it in human readable formatted form
Here is my person class
public class Person implements Serializable {
private String firstName;
private String lastName;
private int age;
public String getFirstName() {
return firstName;
[code]....
I want to know how to use printStream.print() like method to write formatted output.
how is cast a class at a methods parameters? i have a problems in a methods paramter. i draw red line my exception and mymethods is orage color ....
Caffe drink = new Caffe();
CoffeCup cup = new CoffeCup();
cup.setTempeture(100);
drink.drinkcaffe((CaffeCup)(cup.getTempeture()));
[code]....
I have a msg object that contains an ArrayList<Integer> collection. However, in order to send the elements in the array over the udp socket, it needs to be sent as a byte[] array. So why am I using ArrayList<Integer> over byte array in first place? Well when I receive data from socket from embedded c program, I need to get an unsigned representation of the data, and thus I need to store it in integers, since bytes in Java are unsigned and unsigned chars in c that are greater than 127 will yield incorrect values in java. But when I send an ack back over the socket, I need to send the data back as bytes. So I convert the ArrayList<Integer> to a byte array:
Java Code: byte[] data = msg.toByteArray();
DatagramPacket response = new DatagramPacket(data, data.length,
packet.getAddress(), packet.getPort());
public class Gprs {
...
public byte[] toByteArray(){
[Code] ....
The problem is I get an "Cannot cast from Integer to byte" when trying to cast the integer to byte: data[i] = (byte)m_data.get(i);
How can I resolve this?
I'm developing an application to track the status of a production flow-line and have hit a bit of a snag. When attempting to read saved data I run into this:
Exception in thread "main" java.lang.ClassCastException: flowline.End_Of_File cannot be cast to flowline.Operation
at flowline.Station.checkLoadPreviousStationStatus(Station.java:91)
at flowline.Station.main(Station.java:212)
Java Result: 1
I've been reading up on different methods to saving and retrieving data and have decided ObjectInputStream would be the best option.
The save method works fine, I opted to use a EndOfFile class to determine when I've reached the end of the input stream. The problem is, when my loop encounters this object, it doesn't terminate the loop.
public void checkLoadPreviousStationStatus() throws FileNotFoundException, IOException,
ClassNotFoundException, EOFException, TempArrayOutOfBoundsException{
Object loadOpn = null;
End_Of_File eof = new End_Of_File();
File f = new File(fileName);
[Code] .....
The Operation cast is a cast to the objects my LinkedList contains. The highlighted line is where the exception occurs.
I am getting "Type safety: Unchecked cast from Object to LinkedList<EventData>" in eclipse for a piece of code stated below
public LinkedList<EventData> loadFromFile(File file) {
queue=new LinkedList<EventData>();
//Some piece of code
return (LinkedList<EventData>)queue.clone(); //--->getting warning here
}
I know that because clone() method is returning Object, hence compiler doesn't have type information that's why showing warning. I don't want to suppress this warning instead i want to fix it.
Below code I am using to typecast int to char.
char escapeValue = (char)0;
char cha = (char) 10;
escapeValue = (char)(escapeValue * cha); // Here am getting the above error.
I have 38 similar issues in my workspace.
I am inputting a file that has the system output when pinging an ip address. i have gotten it to read the file into an arraylist with readLine. Is there a way to have it input to list using spaces instead of lines?
BufferedReader bf = new BufferedReader(new FileReader(file));
int linecount = 0;
int numberTimes = 0;
String line;
//loop thru file and add contents to an arraylist
while ((line = bf.readLine()) != null) {
inLine.add(line);
}
bf.close();
System.out.println(inLine);
get the arraylist to hold it like this:
(0)Pinging
(1)192.168.1.6
(2)with
(3)32
(4)bytes
(5)of
(6)data
So I am saving a file. it is an array of two strings each containing three words. i figured out how to save to a text file and read it back in and put it back into an array. I am using scanner.hasnext and scanner.next and i think that separates the strings into variables using the spaces in the strings. Well for my project i need to do it with a symbol instead of a space
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Writer;
import java.util.Scanner;
[Code] .....
I put some comments in the read method so you can get exactly what im trying to accomplish....
How do I read in a file line by line into an array without using arraylist?
I know how to do this using BufferedReader, but I am wondering how to do this using Scanner? When I used BufferedReader I noticed that there must be two exceptions to be caught which were IOException and FileNotFoundException, whereas a Scanner needs only a FileNotFoundException, why is that?
Java Code: public class practice {
public String[] array;
Scanner inputStream = null;
Scanner n = new Scanner(System.in);
public String line;
[Code].....
i want to take integer from a file into a string and using stringtokenizer convert them into tokens and collect those tokens into an array and sort it
View Replies View RelatedI have to recursively find a given string in a file. I HAVE to use the LineNumberReader class, and the output would be like so:
Line#Found : the string of the whole line
This is the code I've written:
public String findGivenString(String givenString, int currentLineNumber) {
LineNumberReader lnr = null;
try {
lnr = new LineNumberReader(new FileReader(getFile()), 4096);
lnr.setLineNumber(currentLineNumber);
String s = lnr.readLine().toLowerCase();
[Code] ....
I messed around with a bit, and it doesn't change to the new set line. Though the line number is incrementing! So it just keeps checking the first line of the file over and over again, which is why it can't find the given string. Which also throws the StackOverFlow exception I'm getting.
Here's the output if I remove the comment from the System.out...:
String @ that Line# 1: package banking;
String @ that Line# 2: package banking;
String @ that Line# 3: package banking;
String @ that Line# 4: package banking;
....
So you see it keeps checking the same line even though the line number IS incrementing.
I have a web service which is returning a string. I want to extend this web service so that it returns an xml based string. To begin with I am able to return xml based strings from a normal POJO class ....
View Replies View RelatedWrite a program that removes all the occurrences of a specified string from a text file. For example, invoking java Exercise14_11 John filename removes the string John from the specified file. Your program should get the arguments from the command line.
I have a problem.
Text document is Match.txt
Match.txt contains a string: "Open the door John"
I tried to create a new file named doc.txt where to put the text from the Match.txt without John word
//to read from document
Scanner output = new Scanner("Match.text");
//to write to document
PrintWriter write = new PrintWriter("doc.txt");
//copy from original document
String copy = "";
while(output.hasNextLine())
[code]...
Error :NoSuchElementException
Show me a code where I can get text file all content to String?
View Replies View RelatedI am at a loss when it comes to appending Strings to a text file in Java. I was tasked (yes, homework) to complete a program that does the following simple things:
Print out the contents of a text file to the user (got that!)
Ask the user if the want to add any customers to this text file (got it!)
Add those customer's name's, addresses, postal codes and cities. (got that too)
Verify the postal code is in the proper format (yep!)
Add the new information to the text file, and display it to the user (Nope...)
The program is, essentially, supposed to keep track of the user's customers, and store this information to a text file. However, when I run the following code, I get a number of errors:
static String firstOutput, name, address, city, postalCode, file = "";
static int customer = 0;
static String fileLine = "";
public static void main(String[] args) throws IOException {
file = "C:UsersOwnerDocumentsDiscountFly.txt";
[Code] .....
The errors I get are:
Java.io.exception. Main. Stream closed
ensureOpen (115)
ava.io.BufferedReader.readLine(BufferedReader.java:310)
I understand that the numbers correspond to lines of code (line 115, or 310, for example) but I am unsure of how to fix these errors.