I thought you can use PrintWriter to write to the console but when I run the following code I only get "abc" printed to the console.
import java.io.*;
class Class1{
public static void main(String...abc) throws Exception{
PrintWriter writer = new PrintWriter(System.out);
writer.println("test");
System.out.println("abc");
}
}
I am creating a car simulator that simulators the odometer and fuel gauge on a car. I want to print the results to a text file but it seems to be printing only the last two lines instead of all of them. How can I make it so it doesn't overwrite the previous input?
Here's my main method:
public static void main(String[] args) throws FileNotFoundException {
CarInstrumentSimulator carInstrumentSimulator = new CarInstrumentSimulator();
FuelGauge gas = carInstrumentSimulator.new FuelGauge();
[Code].....
What I'm tasked to do, is to make a simple Java class that forms a "V" based on whatever height the user would desire, made out of stars "*", and spaces " ".
For example, if a user desires a "V" with a height of 3, it would look print out something like;
* *
* *
*
Where a "V" with a height of 5 would look something like:
* *
* *
* *
* *
*
(That one didn't look too good, but you get the point, it's suppose to be 5 "high" and shaped like a "V"). The problem I have, is that I don't see what loops within loops within loops I would need to build something like this.
All the easy stuff like asking the user what height they want and such, I can handle, but I don't see how this thing is suppose to be coded, to print out a decent-looking and right-sized "V" in the console.
public static void main(String[] args) {
int height = 3;
for (int i = 0; i < height; i++) {
for (int j = 0; j < 2/(height+1)+1; j++) {
if(j == i) {
[Code] ....
Looked like something of a good start, and it drew me half (!) of the "V" in the size I wanted. Am I on to it here, or am I on the moon in terms of progress? I need the entire "V", not just a nice "".
You are given a file containing the names and addresses of company employees from many years ago that your manager has asked you to import into a database. You can use a CSV file and your database application to load the file, but the file your manager gave you was exported from an old, non-standard accounting system. Here is its format:
Fred|Flintstone
1212|Bedrock
Austin|Texas
Harry|Potter
1234|Hogwarts Road
[Code] .....
I'm tyring to print the same output in console to a text file, but I can only get the last line of the console output in the text file, not sure what is wrong with my code:
while (in.hasNextLine()) {
PrintWriter writer = new PrintWriter("output5.txt");
tempS = in.nextLine().toLowerCase();
System.out.println(wp.bestPages(tempS));
[code]....
What's causing only the last time to be printed in text file? Are there better ways to print console outputs into a text file than PrintWriter?
I've written a simple html/servlet program that has a user enter their name and password on a form and then either register or login using a submit button. I have the program working, except when a user doesn't fill in either of the text fields I can't figure out how to get it to print to the page. Right now I just have it printing to my Eclipse console which is not what I want. What am I missing?
HTML code:
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Cookies</title>
[code]....
i've got this code that i cant get to work as i want it to. when its exported and i run it the file i wants gets created but when i open the file there is a single number like 999998000001
import java.io.IOException;
import java.io.PrintWriter;
public class mainHej {
public static void main(String arg[]){
[code]...
If I am using the File object to read a file and PrintWriter object to write to a separate file, can I use them under one method. Or is the File one method and the PrintWriter another method?
View Replies View RelatedHow to write a new file:
import acm.program.*;
import java.io.*;
import java.io.PrintWriter.*;
import acm.util.*;
import javax.swing.*;
public class PrintWriter extends ConsoleProgram {
public void run() {
try {
PrintWriter wr = new PrintWriter( new FileWriter ("hello.txt") ) ;
wr.println("Hello world!");
wr.close();
} catch (IOException er) {
println("File could not be saved.");
}
}
}
(I added the imports at top myself.) However, I am getting compiler errors for the lines: PrintWriter wr = new PrintWriter( new FileWriter ("hello.txt") ) , which says that the constructor PrintWriter( FileWriter ) is undefined, and
wr.close();, which says close() method is undefined.
Pretty sure the only real problem is that PrintWriter is not accepting the FileWriter as constructor, but I don't see why. I have tried this on machine with JRE 1.4 and it worked as expected, creating new file titled "hello.txt", prints line of "Hello world!" in that file, and saves it to the directory I picked in the dialog. But I can't get it to work on this machine that uses Compiler 1.6, Java Runtime v8u25.
I have also tried using just a string in the parameter for PrintWriter, such as PrintWriter wr = new PrintWriter ("hello.txt") , and from what I can tell by reading the java spec for java 8, this should work. [URL] .... But I get error message for that constructor as well.
I have done lots of PrintWriting before but this is the first time I have done it on my new computer and I'm having an error I haven't seen before. This is my code:
Rprint(){
try {
PrintWriter pout = new PrintWriter(new FileWriter("C:UsersJackDocumentsexample.r "));
pout.println("nums = c(1,2,5,6,8,10)");
pout.println("nums");
pout.close();
} catch (IOException ex) {
System.out.println("Error!");
Logger.getLogger(Rprint.class.getName()).log(Level .SEVERE, null, ex);
}
}
*** java.io.FileNotFoundException: C:UsersJackDocuments
This.txt (The filename, directory name or volume label syntax is incorrect) ***
I have a feeling it may be to do with permissions, because it lets me print simply ("example.r") into my project folder.
Write a program that asks the user for the names of two files. The first file should be opened for reading and the second file should be opened for writing. Ihe program should read the contents of the first file, change all characters to uppercase, and store the results in the second file. The second file will be a copy of the first file, except that all the characters w ill be uppercase. Use Notepad or another text editor to create a simple file that can be used to test the program
Here is my code. I Also made two text document files that are located in the same directory as the .class file (the code file) that are named OriginalFile and UpperCase respectively. Please let me know what I need to do. Here is the code.
import java.util.Scanner;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
public class UpperCaseFile
{
public static void main (String [] args) throws IOException
{
[Code]...
private static void getTablas(int num) {
//ciclos anidados
System.out.print("x");
//linea horizontal
for (int i = 1; i <= num; i++) {
System.out.printf("%3d ",i);
[Code] .....
Does printwriter always truncates the existing file to 0 size before adding any new data ??
View Replies View RelatedThis is a college course assignment that consists of classes TotalSales and TotalSalesTest.In the main program I have created a two dimensional array to output a columnar layout with cross-totals in 4 rows and 5 columns. This program outputs sales totals by row for each sales person(1 - 4) and output by column for products(1 - 5). I have created extra elements in the array to store total for rows and columns. So far both classes compiles. The problem is that although the PrintWriter creates a notepad file, it doesn't print to it. I don't seem to understand the input and output methods completely. I finished another program similar to this using basically the same try and catch that read the file and printed out a document in notepad. Here is the code and I'll try include the input file.
import java.util.Scanner;
import java.io.*;
public class TotalSales {
private int salesPerson; //declare class variable
private int productNumber;//declare class variable
[code]....
Trying to run my program after getting rid of code errors (I think) and now it doesn't produce anything but <terminated> in the console window. The produce is suppose to analyse text from a file and produce the percentage of words used
package com.project;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.math.BigDecimal;
[Code] ....
erfrf.jpg
This is my program. All is working fine except stopping reading from console. Problem is that even after you write done if you are fast enough you are able to write more. As you can see I can't close scanner because of two inputs. Even so I tried to close it but problem was still here.
public static void main(String...args) {
System.out.println("Write first input:");
System.out.print(streamToString(System.in, ""));
System.out.println("Write secondinput:");
System.out.print(streamToString(System.in, ""));
[Code] .....
How to clear console screen ? I am using Linux machine.
1) Runtime.getRuntime().exec("clear"); // this is not working. Not clearing the screen
2) for ( int i = 0; i < SOME_NUMBER; i++)
System.out.println();
2nd way is working but i think it is not a good option as i need to move scroll bar again and again.
i need to take a txt file and turn it into a csv(comma seperated value) output on console but where to begin.
View Replies View Related"Write a java application that displays the following patterns separately one below the other.
Use for loops to generate the patterns. There are 4 Triangle patterns.
All asterisks (*) should be printed by a single statement of the form System.out.print('*');
This is 4-different patterns, not 1-pattern."
The first 2 triangles are right angles and is simple to make with a loop with in a loop
The 3rd triangle is like an inverted christmas tree and the 4th one is a christmas tree. ( It's not showing properly on the board so i deleted it). I can't seem to make the 3rd and 4th triangle line up properly it looks like this (the _ represents blank spaces on the console)
_____*_____
_____**_____
____***_____
____****_____
___*****____
___******_____
__*******
__********____
Notice how the sides of the triangle isn't straight and the triangle looks like its dancing, the assignment requires it to be a straight line. is there anyway to do this? This is suppose to be the output. all the lines of the triangle is straight and not jagged ...
public class myclass {
public static void main(String[] args) {
int counter = 1;
int counter2 = 1;
while (counter != 11){
EmptyLine();
[Code] .....
My code for those particular triangle is in the work because I cant figure out how to make it look like that.
I want to input character data from the console without using the BufferedReader class. I tried using the Scanner class but the compiler shows an error. This is what I tried:
sc.nextCharacter();
sc.nextcharacter();
sc.nextChar();
Sc.nextchar();
Is there any way I can input character data without using the BufferedReader class?
I have a multithreaded java program. I have a few worker threads which process data over a udp server. Then I have another thread for console input. The problem is when there is an error with one of the worker threads, and it prints to the console, my console thread loses "focus", that is, the while loop seems to no longer run. Here is the console thread:
Java Code:
public void run() {
Console c = System.console();
if (c == null) {
Logger.writeError("No console.");
System.exit(1);
}
while(true){
String login = c.readLine(">>>: ");
System.out.println("You entered: " + login);
}
} mh_sh_highlight_all('java');
When an exception is raised, it prints it to the console, and suddenly the program no longer shows the >>> prompt from above.
I seem to be having a issue with my java console app what it should do is query a SQL DB and list the user details (userid, firstname ,lastname) from the user table, and the users stocks (stockname ,stockdiscription) associated to each user from the userstocks table if I'm thinking correctly!
I'm sure it is just a logical error, but I'm not sure of the way to get the out put I'm looking for. I will add the makeDB.java file and DatabaseQuery.java file as well as the current Exception(Run Time Exception) below.
**I have added other users and stocks manually - Not just what the MakeDB.java file inserts **
Output and Exception:
Stock holdings by User
User ID User Name
Stock - Description
-------------------------------------------
admin01 Default Admin
Exception in thread "main" java.sql.SQLException: ResultSet is closed
at sun.jdbc.odbc.JdbcOdbcResultSet.checkOpen(JdbcOdbcResultSet.java:6647
)
at sun.jdbc.odbc.JdbcOdbcResultSet.next(JdbcOdbcResultSet.java:1248)
at DatabaseQuery.main(DatabaseQuery.java:45)
Press any key to continue . . .
Java Code:
MakeDB.java:
import java.sql.*;
import java.io.*;
public class MakeDB
{
public static void main(String[]args) throws Exception
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
[Code] ....
I have written a shell script which connects to oracle database and performs operation and returns some output message. Script works fine from command prompt. My requirement is to make it run from a web page which I have accomplished. I am getting the output of shell script on a different web page defined by HTML form action in my jsp file. Everything is working fine.
Below is the part of java class I have written:
=============
String fileName = "build_"+ request.getParameter("region");
String arg1 = request.getParameter("release");
String arg2 = request.getParameter("email");
ProcessBuilder pb = new ProcessBuilder(fileName,arg1,arg2);
Process p = pb.start();
InputStream inputStream = p.getInputStream();
[Code] ....
As shown above, my shell script accepts 2 arguements . User enters arguements in the fields provided which are passed to shell script by processbuilder. Script runs successfully and displays output [ success/error ].
But my problem is , the shell script takes nearly 1 hour to do its job in the database and untill then my web page keeps showing as busy. Whereas in command prompt, shell script displays messages as it runs and thus keeps the end user informed about its progress. However, when called from java it waits untill the shell script completes/terminates and finally displays all the messages at once. I want to know if there is a way to display the shell script output on web page as it continues to run in the background ( child process ).
I tried without the waitFor() function but no luck. It still waits for shell script to exit before displaying any message.
I created a calendar program so when the user enters a day number and a year it would show the calendar for the year . My issue was that I could not get the numbers to line up neatly and how they should look . Also if its not to much trouble I would like to know how to turn this in to a loop .
import java.util.Scanner;
public class Calendar {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter a Year");
int Year = scanner.nextInt();
[Code] .....
I am having a great deal of frustration trying to use the scanner to get user input from the eclipse console. Here is what I am trying to do.
Print a menu for the user with options, take that (1) char input and run it into a switch statement for processing. I have that done and it is working fine.
If the user chooses to enter strings for storage, They are instructed to enter their string and press enter to complete that string entry. Then enter the next string and press enter, etc.
So I have a While loop for this. Get the scanner input, store it in the LinkedList, get the next scanner input, etc. I get the scanner string and store it in a Linked list. That works fine. The user is instructed to simply enter a blank string to end the entry procedure, like just press Enter on the new line without typing a new string.
The problem is the scanner doesn't seem to return anything for me to Test to close this procedure. How do I TRAP the fact that the user just pressed enter so I can end my procedure? I have tried next() and nextLine() and reset(), etc. And I am getting knowhere.
Follow the //? FIRST and SECOND notes, then I understood that Java has GOTO as Keyword for future versions and that usually one can avoid GOTO using break inside the cycles, but I need a jump( salto) in the code.
import java.util.Scanner;
public class ArrayOrdinati {
public static void main (String[] args){
int[] Array = {5,3,1};
int e=Array.length;
int b;
[Code] .....