import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.*;
public class fileprint {
public static void main(String args[]){
String title;
String desc;
//scanner
Scanner sc = new Scanner(System.in);
//--file--//
String fileName = "print.txt";
PrintWriter writer = null;
try
{
writer = new PrintWriter(fileName);
} catch (FileNotFoundException e)
{
e.printStackTrace();
}
//--end--//
System.out.print("Enter a title:");
title = sc.nextLine();
writer.println(title);
do
{
System.out.println("Enter a description: ");
desc = sc.nextLine();
writer.println(desc);
}while(!desc.equals("END"));
writer.close();
}//end main
}//end class
Above is my code, I have successfully completed the program and it's functioning as intended. However I would like the printed string (title) in .txt file to be aligned in the center of my description. My current output in the .txt file is like this:
As you can see, the word "title" is at the most left of the .txt file and I would like it to be in the center of "cats and dogs" and "are best friends." I am also trying to remove the word "END" from the .txt file, this was not intended but writer.print(value) has taken in "END" and has printed it to the .txt file. What are my options here?
Related
I'm trying to show covid data in each line that will be separated into tabs (like a table) and the numeric values will be divided by the thousands separator.
I'm also trying to use a printf statement so i can specify each line to be formatted in that way but im not sure how to do that.
The result I'm looking for:
Global 213,752,662 4,519,052 655,952
What I'm getting:
Global 213752662 4519052 655952
My Code:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;
public class COVIDdata {
public static void main(String[] args) throws FileNotFoundException {
//printing header//
System.out.println("Name\t\t\tTotal Cases\tNew Cases\tNew Cases");
System.out.println("\t\t\t\t\t7 Days \t\t24 Hours");
System.out.println("--------------------------------------------------------------------------------------");
//opening the file//
try {
File file = new File("C:\\Desktop\\COVID-19GlobalData.txt");
Scanner scan = new Scanner(file);
while (scan.hasNextLine()) {
System.out.println(scan.nextLine());
}
while(scan.hasNext()) {
System.out.printf("%,d\n" , int);
}
scan.close();
} catch (IOException e) {
System.out.println("Error reading file");
e.printStackTrace();
}
}
}
This loop will exhaust the entire file scanner and print the file as-is with no formatting
while (scan.hasNextLine()) {
System.out.println(scan.nextLine());
}
You need to parse the lines then include the tabs in your output between several numbers. Something like
while (scan.hasNextLine()) {
String line = scan.nextLine();
String[] parts = line.split("\\s+");
System.out.printf("Global\t%,d\t%,d\n", Long.parseLong(parts[1]), Long.parseLong(parts[2]));
}
I need to do the following exercise:
a) Make a new text file
b) Put the user's input into that text file
c) we must save all user's input while user keeps typing but as soon as user pressing Enter in a new line (When an empty string is sent) the user must get out of the program.
For coding this issue I have write the following codes, but when
I try it by myself so I am stuck at while loop, cant get out when I sending empty string.
So could anyone help with a solution for this issue?
Thanks
I have tried some of the solutions I have found on youtube like making if statement inside the while loop or adding the code that takes the input of the user inside the loop's condition.
So I do not know what to do at the next stage.
I tried to see the console window via the Eclipse output.
import java.io.*;
import java.util.Scanner;
public class lesson {
public static void main(String[] args) throws IOException {
File file = new File("mytext.txt");
if (file.exists() == false) {
file.createNewFile();
}
PrintWriter pw = new PrintWriter(file);
System.out.println("Enter a text here: ");
String str;
while (true) {
Scanner input = new Scanner(System.in);
str = input.next();
pw.println();
if (str.equals(null)) {
break;
}
}
pw.close();
System.out.println("Done");
}
}
The user must get out of the loop when he/she sends an empty string. and the writing to the file must be finished.
First the code, then the explanation...
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
public class Lesson {
public static void main(String[] args) {
File file = new File("mytext.txt");
try (Scanner input = new Scanner(System.in);
PrintWriter pw = new PrintWriter(file)) {
System.out.println("Enter a text here: ");
String str = input.nextLine();
while (str.length() > 0) {
pw.println(str);
pw.flush();
str = input.nextLine();
}
}
catch (IOException xIo) {
xIo.printStackTrace();
}
System.out.println("Done");
}
}
The above code requires at least Java 7 since it uses try-with-resources. Scanner should be closed, just like PrintWriter should be closed. The try-with-resources ensures that they are closed. Note that if file mytext.txt doesn't exist, creating a new PrintWriter will also create the file and if the file already exists, its contents will be removed and replaced with the text that you enter.
After that the prompt is displayed, i.e. Enter a text here, and the user enters a line of text. Method nextLine() will get all the text entered until the user presses Enter. I read your question again and the program should exit when the user presses Enter without typing any text. When the user does this, str is an empty string, i.e. it has zero length. That means I need to assign a value to str before the while loop, hence the first call to method nextLine() before the while loop.
Inside the while loop I write the value entered by the user to the file mytext.txt and then wait for the user to enter another line of text. If the user presses Enter without typing any text, str will have zero length and the while loop will exit.
Written and tested using JDK 12 on Windows 10 using Eclipse for Java Developers, version 2019-03.
To achieve this, we check is length of input is >0:
import java.io.*;
import java.util.Scanner;
public class lesson {
public static void main(String[] args) throws IOException {
File file = new File("mytext.txt");
if (file.exists() == false) {
file.createNewFile();
}
PrintWriter pw = new PrintWriter(file);
System.out.println("Enter a text here: ");
String str;
Scanner input = new Scanner(System.in);
while ((str = input.nextLine()).length() > 0) {
//str = input.next();
pw.println(str);
}
pw.close();
System.out.println("Done");
}
}
Good Morning. Having trouble with a parser using split method. Goal is to read in txt file, extract should statements, then write a new txt file with those should statements. I have it working when the text is on one continuous line. If I have a new line in the txt file, rewrites the file with just the last line. Possibly the structure of my loops? Also any suggestions for saving new file from the directory in which it was opened? Thank you
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
/*This Program Will launch a File Explorer.
User will then chose a .txt file to be parsed.
A new file will be created labeled "Parsed_(Document Name)".*/
public class Parser {
#SuppressWarnings("resource")
public static void main(String[] args) {
JFileChooser chooser = new JFileChooser();
Scanner userFile = new Scanner(System.in);
int returnVal = chooser.showOpenDialog(null);
if (returnVal == JFileChooser.APPROVE_OPTION) {
try {
System.out.println("You chose to open this file: " + chooser.getSelectedFile().getName() + "\n");
File file = new File(chooser.getSelectedFile().getName());
String newFile = ("Parsed_" + file);
userFile = new Scanner(file);
while (userFile.hasNextLine()) {
String document = userFile.nextLine();
// Line breaks used by Parser
String[] sentences = document.split("\\.|\\?|\\!|\\r");
List<String> ShouldArray = new ArrayList<String>();
for (String shouldStatements : sentences) {
if (shouldStatements.contains("Should") || shouldStatements.contains("should"))
ShouldArray.add(shouldStatements);
}
FileWriter writer = new FileWriter(newFile);
BufferedWriter bw = new BufferedWriter(writer);
for (String shallStatements : ShouldArray) {
System.out.println(shallStatements);
bw.append(shallStatements);
bw.newLine();
}
System.out.println("\nParsed Document Created: " + newFile);
JOptionPane.showMessageDialog(null, "Parsed Document Created: " + newFile);
bw.close();
writer.close();
}
userFile.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
Test file 1 (works!)
Hello all. Here is a a packing list. You Should have a toothbrush. You should have a Phone charger. And you definitely should have your wallet!
Test file 1 output:
You Should have a toothbrush
You Should have a Phone charger
And you definitely should have your wallet
Test file 2 (Only printing last line)
Hello all. Here is a a packing list. You Should have a toothbrush. You Should have a Phone charger.
Here is some random text to show the parser will not include this.
You definitely should have your wallet!
test file 2 output:
You definitely should have your wallet
You need to create your result array outside of the loop
/** Placed here**/
List<String> ShouldArray = new ArrayList<String>();
while (userFile.hasNextLine()) {
String document = userFile.nextLine();
// Line breaks used by Parser
String[] sentences = document.split("\\.|\\?|\\!|\\r");
/** REMOVED HERE **/
for (String shouldStatements : sentences) {
if (shouldStatements.contains("Should") || shouldStatements.contains("should"))
ShouldArray.add(shouldStatements);
}
......
otherwise you will only gather the results of your last loop.
Basically what your code was doing:
cut up file in lines
take each line
take next line
make a result board.
write results on board
take next line
erase board
write results on board
take next line
erase board
write results on board
and then at the end there is only a limited resultset on your board
You are overriding your Arraylist within the loop, however you don't actually need it
File file = chooser.getSelectedFile();
System.out.println("You chose to open this file: " + file.getName() + "\n");
String newFile = "Parsed_" + file.getName();
// open all closable objects using try-with-resources
try (Scanner userFile = new Scanner(file);
BufferedWriter bw = new BufferedWriter(new FileWriter(newFile))) {
while (userFile.hasNextLine()) {
String document = userFile.nextLine();
// Line breaks used by Parser
String[] sentences = document.split("\\.|\\?|\\!|\\r");
for (String s : sentences) {
if (s.contains("Should") || s.contains("should")) {
System.out.println(s);
bw.append(s);
bw.newLine();
}
}
System.out.println("\nParsed Document Created: " + newFile);
JOptionPane.showMessageDialog(null, "Parsed Document Created: " + newFile);
// bw.close(); // not needed anymore
I've refactored the code, removing the "ShouldArray", which is not needed.
Pseudocode
While there are lines to read in the In file
Read each line
Split each line into Array of sentences
Loop through each sentence
If each sentence contains Should or should Then
Write sentence to Out file
End If
End Loop
End While
Close Out file
Close In file
The code below works with:
Multi line:
Hello all. Here is a a packing list.
You Should have a toothbrush. You Should have a Phone charger.
Here is some random text to show the parser will not include this.
You definitely should have your wallet!
Single line:
Hello all. Here is a a packing list. You Should have a toothbrush. You should have a Phone charger. And you definitely should have your wallet!
import java.util.Scanner;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.File;
public class ShouldStringsParser {
public ShouldStringsParser(String inFile, String outFile) throws IOException {
File file = new File(inFile);
FileWriter writer = new FileWriter(outFile);
BufferedWriter bw = new BufferedWriter(writer);
Scanner userFile;
userFile = new Scanner(file);
String[] sentences;
while (userFile.hasNextLine()) {
String line = userFile.nextLine();
System.out.println(line);
sentences = line.split("\\.|\\?|\\!|\\r");
for (String shouldStatements : sentences) {
if (shouldStatements.contains("Should") || shouldStatements.contains("should")) {
System.out.println(">>>" + shouldStatements);
bw.append(shouldStatements);
bw.newLine();
}
}
}
bw.close();
writer.close();
userFile.close();
}
public static void main(String[] args) {
try {
new ShouldStringsParser("inDataMultiLine.txt", "outDataMultiLine.txt");
new ShouldStringsParser("inDataSingleLine.txt", "outDataSingleLine.txt");
} catch (IOException e) {
e.printStackTrace();
}
}
}
I have a problem and hope to find a solution.
now i have created a simple program to change password of user account using text files in java.
now i should enter username of the account then change password of that account but there it shows me an error.
here is my code:
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Objects;
import java.util.Scanner;
public class Test6 {
public static void main(String[] args)throws IOException {
String newPassword=null;
boolean checked = true;
File f= new File("C:\\Users\\فاطمة\\Downloads\\accounts.txt");// path to your file
File tempFile = new File("C:\\Users\\فاطمة\\Downloads\\accounts2.txt"); // create a temp file in same path
BufferedWriter writer = new BufferedWriter(new FileWriter(tempFile));
Scanner sc = new Scanner(f);
System.out.println("Enter account username you want to edit password?");
Scanner sc2 = new Scanner(System.in);
String username = sc2.next();
while(sc.hasNextLine())
{
String currentLine= sc.nextLine();
String[] tokens = currentLine.split(" ");
if(Objects.equals(Integer.valueOf(tokens[0]), username) && checked)
{
sc2.nextLine();
System.out.println("New Password:");
newPassword= sc2.nextLine();
currentLine = tokens[0]+" "+newPassword;
checked = false;
}
writer.write(currentLine + System.getProperty("line.separator"));
}
writer.close();
sc.close();
f.delete();
boolean successful = tempFile.renameTo(f);
}
}
the error shows to me:
Exception in thread "main" java.lang.NumberFormatException: For input string: "HAMADA"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.valueOf(Integer.java:766)
at Test6.main(Test6.java:25)
the format of my text file is like that:
HAMADA 115599
JOHNY 4477100
Change Integer.valueOf(tokens[0]) on line 25 to just tokens[0].
In your code, you try to get the integer value of the username, when you should be getting its String representation. You do not need the Integer.valueOf(). (The error is thrown because you are trying to get the Integer representation of a non-integer type.)
On a side note, you should never have password-storing text files, especially when the passwords and the files are both unencrypted. Use a database instead.
So I am trying to search through a text file and if the user input is found, it returns the entire sentence including white spaces.But apparently I only get the first string and nothing pass the first string in the sentence. For example if i have a text file called "data.txt" and the contents in the first line is " I am a legend". after user enters "I am a legend" the output after the file is searched is "I". Any help would be appreciated.
public static void Findstr() { // This function searches the text for the string
File file = new File("data.txt");
Scanner kb = new Scanner(System.in);
System.out.println(" enter the content you looking for");
String name = kb.next();
Scanner scanner;
try {
scanner = new Scanner(file).useDelimiter( ",");
while (scanner.hasNext()) {
final String lineFromFile = scanner.nextLine();
if (lineFromFile.contains(name)) {
// a match!
System.out.println("I found " + name);
break;
}
}
} catch (IOException e) {
System.out.println(" cannot write to file " + file.toString());
}
package com.example;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class FileSearch {
public void parseFile(String fileName,String searchStr) throws FileNotFoundException{
Scanner scan = new Scanner(new File(fileName));
while(scan.hasNext()){
String line = scan.nextLine().toLowerCase().toString();
if(line.contains(searchStr)){
System.out.println(line);
}
}
}
public static void main(String[] args) throws FileNotFoundException{
FileSearch fileSearch = new FileSearch();
fileSearch.parseFile("src/main/resources/test.txt", "am");
}
}
test.txt contains:
I am a legend
Hello World
I am Ironman
Output:
i am a legend
i am ironman
The above code does case insensitive search. You should use nextLine() to get the complete line. next() breaks on whitespaces.
Reference:
http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#next()
Scanner.next(); returns the next caracter instead use Scanner.readLine();
Edit:
Belive Scanners use .nextLine(); not .readLine();
When you are scanning your input..
Scanner kb = new Scanner(System.in);
System.out.println(" enter the content you looking for");
String name = kb.next();
You are accepting only one token. You should accept whole line to be searched as your token using kb.nextLine()