I am trying to count line no. of a file using Java LineNumberReader. The output comes with problem. The problem is the alternative lines are displayed like line no. 1,3,5,... and on counting total no of lines i got half no. of the total actual lines. Here is the code
import java.lang.*;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
public class countLine{
File file=null;
public countLine(){
file =new File("E:\\test.txt");
getFileData();
}
public void getFileData(){
try{
if(file.exists()){
FileReader fr = new FileReader(file);
LineNumberReader lnr = new LineNumberReader(fr);
int linenumber = 0;
do{
System.out.println(lnr.readLine());
linenumber++;
}while (lnr.readLine() != null);
System.out.println("Total number of lines : " + linenumber);
lnr.close();
}else{
System.out.println("File does not exists!");
}
}
catch(Exception e){
e.printStackTrace();
}
}
public static void main(String h[]){
countLine cl = new countLine();
}
}
You read the line twice, once with System.out.println(lnr.readLine()); and once with while (lnr.readLine() != null);
Combining the two other answers into one gives correct line count as well as the ability of doing the System.out.println(...) with line content:
int linenumber = 0;
String tmp = new String();
while ((tmp = lnr.readLine()) != null) {
linenumber++;
System.out.println(tmp);
}
This would have been enough for counting:
FileReader fr = new FileReader(file);
LineNumberReader lnr = new LineNumberReader(fr);
while (lnr.readLine() != null);
System.out.println( lnr.getLineNumber() );
lnr.close();
Added later Or, if you need to print lines (+ line numbers):
String line = null;
while ((line = lnr.readLine()) != null){
System.out.println( lnr.getLineNumber() + " " + lnr.getLineNumber() );
}
You can get the number of lines with two lines of code: something like
lineNumberReader.skip(Long.MAX_VALUE);
int count = LineNumberReader.getLineNumber();
E&OE
Every lnr.readLine() read a line from the file and return it.
You are making two reads:
1)At the System.out.println
2)At the while statement
You need make a call to readLine method,
save the result at variable and when it a null is the end of the file.
Take a look at:
int linenumber = 0;
String tmp = new String();
while ((tmp = lnr.readLine()) != null) {
linenumber++;
System.out.println(tmp);
}
Related
I'm trying to do a simple login from a textfile. I've used different ways of reading the text from the file to a String line(BufferedReader and Scanner). I am able to get the line into a string, but it doesn't want to compare the 2 strings and match when I use an if statement(.equals()) or even if I use .equalsIgnoreCase(). When I print the 2 strings to be compared they are the same. but my if statement doesn't seem to return true?
This was the last coding i tried (I thought maybe if I put it into an array it would compare true, but still nothing).
Iv'e looked and saw similar questions to comparing strings from textfile, but never saw a problem with the if statement to return true
import java.io.*;
import java.text.*;
import java.lang.*;
public class tes
{
public static void main(String[] args)throws Exception
{
String logline = "JMX^1234";
ArrayList<String> lines = new ArrayList<String>();
FileReader fr = new FileReader("/home/jmx/Desktop/javap/Bank/jm.txt");
BufferedReader br = new BufferedReader(fr);
String rline = br.readLine();
while(rline != null)
{
lines.add(rline);
rline = br.readLine();
}
String[] users = new String[lines.size()];
lines.toArray(users);
for(int i = 0; i < users.length; i++)
{
if(logline.equals(users[i]))
{
System.out.println("Matched");
}
}
System.out.println("Login line: " + logline);
System.out.println("Text Line: " + users[0]);
br.close();
fr.close();
}
}
I've tried to execute your code and everything worked as expected. I received "matched". Maybe it's some kind of encoding issue. Try to compare length and if it is ok, try to leave only one line in the file and try this code:
String logline = "JMX^1234";
ArrayList<String> lines = new ArrayList<String>();
FileReader fr = new FileReader("/home/jmx/Desktop/javap/Bank/jm.txt");
BufferedReader br = new BufferedReader(fr);
String rline = br.readLine();
while(rline != null)
{
lines.add(rline);
rline = br.readLine();
}
String[] users = new String[lines.size()];
lines.toArray(users);
for (char ch : users[0].toCharArray()) {
System.out.print((int)ch);
}
System.out.println();
for (char ch : logline.toCharArray()) {
System.out.print((int)ch);
}
System.out.println();
for(int i = 0; i < users.length; i++)
{
if(logline.equals(users[i]))
{
System.out.println("Matched");
}
}
System.out.println("Login line: " + logline);
System.out.println("Text Line: " + users[0]);
br.close();
fr.close();
It should return equal lines of numbers like this:
7477889449505152
7477889449505152
Matched
Login line: JMX^1234
Text Line: JMX^1234
Also try to check out this answer: https://stackoverflow.com/a/4210732/6226118
I have a text file with 5 lines, I wish to read in those lines and be able to number them 1 - 5, and save them in a different file. The numbers begin before the start of the line. I have tried to hard code in a loop to read in the number but I keep getting errors.
public class TemplateLab5Bronze {
static final String INPUT_FILE = "testLab5Bronze.txt";
static final String OUTPUT_FILE = "outputLab5Bronze.txt";
public static void main(String[] args) {
try {
FileReader in = new FileReader(INPUT_FILE);
PrintWriter out = new PrintWriter(OUTPUT_FILE);
System.out.println("Working");
BufferedReader inFile = new BufferedReader(in);
PrintWriter outFile = new PrintWriter(out);
outFile.print("Does this print?\n");
String trial = "Tatot";
outFile.println(trial);
System.out.format("%d. This is the top line\n", (int) 1.);
System.out.format("%d. \n", (int) 2.);
System.out.format("%d. The previous one is blank.\n", (int) 3.);
System.out.format("%d. Short one\n", (int) 4.);
System.out.format("%d. This is the last one.\n", (int) 5.);
/*if(int j = 1; j < 6; j++){
outFile.print( i + trial);
}*/
String line;
do {
line = inFile.readLine();
if (line != null) {
}
} while (line != null);
inFile.close();
in.close();
outFile.close();
} catch (IOException e) {
System.out.println("Doesnt Work");
}
System.out.print("Done stuff!");
}
}
This is all the code I have so far, excluding the import statements, the commented for loop is what I was trying to use. Is there another way to do this?
One way to do it is to add to the printWriter while looping through the existing file:
FileReader fr = new FileReader("//your//path//to//lines.txt");
BufferedReader br = new BufferedReader(fr);
try (PrintWriter writer = new PrintWriter("//your//other//path//newlines.txt", "UTF-8")) {
String line;
int num = 1;
while ((line = br.readLine()) != null) {
writer.println(num + ". " + line);
num++;
}
}
Note: I didn't put in any catch statements, but you might want to catch some/all of the following: FileNotFoundException, UnsupportedEncodingException, IOException
You don't need two PrintWriters. Use only one.
PrintWriter outFile = new PrintWriter(OUTPUT_FILE);
You can simply use a counter instead of a for loop (which you have incorrectly written as if - as mentioned by #Shirkam)
String line;
int count=1;
do {
line = inFile.readLine();
if (line != null) {
outFile.println( count++ +"." + line);
}
} while (line != null);
inFile.close();
This works fine at my end.
I have to count the characters in a text file.
I would like to do it with a for loop, however, I do not know how to refer to the length of the file?
public void countLetters(String) {
for (int i = 0; i < ; i++) {
}
}
What should I write after the i < ?
Well you first need to read the contents of the file. You can do it the following manner.
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
Where file is the file object i.e in your case, the text file which you want to read. Then read each line of the file, like this
String temp;
int totalNoOfCharacters = 0;
int noOfLines = 0; //To count no of lines IF you need it
while ( (temp = br.readline()) != null ){
noOfLines++;
totalNoOfCharacters += temp.length(); //Rememeber this doesnot count the line termination character. So if you want to consider newLine as a character, add one in this step.
}
FileReader fr = new FileReader("pathtofile");
BufferedReader br = new BufferedReader(fr);
String line = "";
int cont=0;
while ((line = br.readLine()) != null) {
line = line.split("\\s+").trim();
cont+=line.length();
}
Don't forget to close streams and use try catch .
Maybe better to read each each character within a while loop that first checks for the end of the file than to try using a for loop.
e.g.
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
. . . .
. . . .
try
{
BufferedReader reader = new BufferedReader(new FileReader("myFile.txt"));
String textLine = reader.readLine();
int count = 0;
while (textLine != null)
{
textLine.replaceAll("\\s+",""); // To avoid counting spaces
count+= textLine.length();
textLine = reader.readLine();
}
reader.close();
System.out.println("Number of characters in myFile.txt is: " + count);
}
catch(FileNotFoundException e)
{
System.out.println("The file, myFile.txt, was not found");
}
catch(IOException e)
{
System.out.println("Read of myFile.txt failed.");
e.printStackTrace();
}
Scanner scanner = new Scanner(yourfile);
while(scanner.hasNext()){
word = scanner.next();
char += word.length();
}
I'm writing a code that uses an input file called InvetoryReport.txt in a program I am supposed to create that is supposed to take this file, and then multiply two pieces of data within the file and then create a new file with this data. Also at the beginning of the program it is supposed to ask you for the name of the input file. You get three chances then it is to inform you that it cannot find it and will now exit, then stop executing.
My input file is this
Bill 40.95 10
Hammer 1.99 6
Screw 2.88 2
Milk .03 988
(The program is supposed to multiply the two numbers in the column and create a new column with the sum, and then under print another line like this
" Inventory Report
Bill 40.95 10 409.5
Hammer 1.99 6 11.94
Screw 2.88 2 5.76
Milk .03 988 29.64
Total INVENTORY value $ 456.84"
and my program I have so far is this
package textfiles;
import java.util.Scanner;
import java.io.PrintWriter;
import java.io.IOException;
public class LookOut{
double total = 0.0;
String getFileName(){
System.out.printIn("Type in file name here.");
try {
int count =1;
FileReader fr = new FileReader("InventoryReport.txt");
BufferedReader br = new BufferedReader(fr);
String str;
while ((str = br.readLine()) != null) {
out.println(str + "\n");
}
br.close();
} catch (IOException e) {
if(count == 3) {
System.out.printIn("The program will now stop executing.");
System.exit(0);
count++;
}
}
return str;
}
void updateTotal(double d){
total = total + d;
}
double getLineNumber(int String_line){
String [] invRep = line.split(" ");
Double x = double.parseDouble(invRep[1]);
Double y = double.parseDouble(invRep[2]);
return x * y;
}
void printNewData(String = newData) {
PrintWriter pW = new PrintWriter ("newData");
pw.print(newData);
pw.close;
}
public static void main(String[] args){
String str = ("Get file name");
String str = NewData("InventoryReport/n");
File file = new File(str);
Scanner s = new Scanner(file);
while(s.hasNextLine()) {
String line = s.nextLine();
double data = getLineNumber(line);
update total(data);
NewData += line + " " + data + "/n";
Print NewData(NewData);
}
}
}
I'm getting multiple error codes that I just cant seem to figure out.
try {
int count =1;
FileReader fr = new FileReader("InventoryReport.txt");
BufferedReader br = new BufferedReader(fr);
String str;
while ((str = br.readLine()) != null) {
br.close();
} catch (IOException e) {
if(count == 3) {
System.out.printIn("The program will now stop executing.");
System.exit(0);
count++;
}
}
Despite your best intentions you are in fact missing a '}'. Note that you haven't escaped the Try block before the catch. I imagine this is because you confused the closing } for the while statement as the closing } for the try block. Do this instead:
try {
int count =1;
FileReader fr = new FileReader("InventoryReport.txt");
BufferedReader br = new BufferedReader(fr);
String str;
while ((str = br.readLine()) != null) {
br.close();
}
}
catch (IOException e) {
if(count == 3) {
System.out.printIn("The program will now stop executing.");
System.exit(0);
count++;
}
}
Also, your indentation is ALL OVER THE PLACE. This should be a lesson to you in why you should format your code properly! It is so easy to miss simple syntax errors like that if you're not formatting properly. It's also hard for others to read your code and figure out what's wrong with it.
I am using a .txt file that contains: "Hello world\nHow are you doing this day?" I want to count whether a line contains a string or not, as well as the total number of lines. I use:
File file = new File(file_Path);
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
int i=0;
int j=0;
while ((line = br.readLine()) != null) {
j++;
if (line.contains("o")) { //<----------
i++;
}
}
System.out.print("Lines containing the string: " + i + " of total lines " + j-1);
As I run and test line.contains("o"), it prints 2 lines containing "o", which is correct as well as 2 total lines. As I run line.contains("world"), it prints 0 lines which is wrong but gives 2 lines total. But what do I do wrong?
I tested it with a StringReader,
String str = "Hello world\nHow are you doing this day?";
StringReader sr = new StringReader(str);
try {
BufferedReader br = new BufferedReader(sr);
String line;
int i = 0;
int j = 0;
while ((line = br.readLine()) != null) {
j++;
if (line.contains("world")) { // <----------
i++;
}
}
System.out
.println("Lines containing the string: " + i
+ " of total lines " + j);
} catch (Exception e) {
e.printStackTrace();
}
Your file contents must not be what you think because I get
Lines containing the string: 1 of total lines 2
As the others answers and comments, I also think you may not be reading the file you think you are... (Relax it happens to everyone from time to time)
But, also it could be the encoder of the file or the version of the jdk you have, maybe if you could answer:
What did you use to create the file?
What OS you are running
this?
What JDK are you using?
It could clarify what may have happened
Just for you to know, I ran the same code you have using jdk8 and worked fine for me.
As follows the test I did:
1) I put your code in a function:
int countLines(String filename, String wording) {
File file = new File(filename);
String line;
int rowsWithWord = 0;
int totalRows = 0;
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
while ((line = br.readLine()) != null) {
totalRows++;
if (line.contains(wording)) {
rowsWithWord++;
}
}
} catch (IOException e) {
System.out.println("Error Counting: " + e.getMessage());
}
System.out.println(String.format("Found %s rows in %s total rows", rowsWithWord, totalRows));
return rowsWithWord;
}
2) and ran the following unit test
#Test
public void testFile() {
try (FileWriter fileWriter = new FileWriter(new File("C:\\TEMP\\DELETE\\Hello.txt"));
BufferedWriter writer = new BufferedWriter(fileWriter)) {
writer.write("Hello world\nHow are you doing this day?");
} catch (IOException e) {
System.out.println("Error writing... " + e);
}
int countO = fileUtils.countLines("C:\\TEMP\\DELETE\\Hello.txt", "o");
Assert.assertEquals("It did not find 2 lines with the letters = o", 2, countO);
int countWorld = fileUtils.countLines("C:\\TEMP\\DELETE\\Hello.txt", "world");
Assert.assertEquals("It did not find 1 line with the word = world", 1, countWorld);
}
And I got the expected result:
Found 2 rows in 2 total rows
Found 1 rows in 2 total rows