We Keep Coding

how to use relative file path to read a file in java?

file path is not working, input1.txt is located in the same directory as library.java.
What should i do to correct it ?
How should i give path so that it read thr text file ?
package SimpleLibrarySystem;
import java.time.LocalDateTime;
import java.util.*;
import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
public class Library
{
ArrayList <Book> var = new ArrayList<Book>();
HashMap<Book, LocalDateTime> var1 = new HashMap<Book, LocalDateTime>();
public Library(String person, LocalDateTime time)
{
try{
File myfile = new File("input1.txt") ;
Scanner br = new Scanner(myfile);
String line = br.nextLine();
while ((line != null))
{
String a = line;
line = br.nextLine();
String b = line;
Book a1 = new Book(a,b,person);
Book a2 = new Book (a,b, "");
var.add(a2);
var1.put(a1,time);
//System.out.println(a + " "+ b);
line = br.nextLine();
}
br.close();
}
catch (Exception e)
{
System.out.println("not working");
}
}
}

with code:
public class Main{
public static void main(String[] args) {
int counter = 0;
try (FileReader fileReader = new FileReader("src/file.txt"); Scanner sc = new Scanner(fileReader)) {
while (sc.hasNextLine()) {
++counter;
sc.nextLine();
}
} catch (Exception e) {
throw new IllegalStateException(e.getMessage());
}
System.out.println(counter);
}
}
checkout: how to read file in Java

Want to find content difference between two text files with java

I have two text files,
a.txt
b.txt
Each text files contains some file paths. b.txt contains some more file paths than a.txt. I would like to determine which paths are added and which are removed from a.txt so that it corresponds to paths in b.txt.
For example,
abc.txt contains
E:\Users\Documents\hello\a.properties
E:\Users\Documents\hello\b.properties
E:\Users\Documents\hello\c.properties
and xyz.txt contains
E:\Users\Documents\hello\a.properties
E:\Users\Documents\hello\c.properties
E:\Users\Documents\hello\g.properties
E:\Users\Documents\hello\h.properties
Now how to find that g.prop and h.prop are added and b.prop is removed?
Could anyone explain how it is done? I could only find how to check for identical contents.

The below code will serve your purpose irrespective of the content of the file.
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
public class Test {
public Test(){
System.out.println("Test.Test()");
}
public static void main(String[] args) throws Exception {
BufferedReader br1 = null;
BufferedReader br2 = null;
String sCurrentLine;
List<String> list1 = new ArrayList<String>();
List<String> list2 = new ArrayList<String>();
br1 = new BufferedReader(new FileReader("test.txt"));
br2 = new BufferedReader(new FileReader("test2.txt"));
while ((sCurrentLine = br1.readLine()) != null) {
list1.add(sCurrentLine);
}
while ((sCurrentLine = br2.readLine()) != null) {
list2.add(sCurrentLine);
}
List<String> tmpList = new ArrayList<String>(list1);
tmpList.removeAll(list2);
System.out.println("content from test.txt which is not there in test2.txt");
for(int i=0;i<tmpList.size();i++){
System.out.println(tmpList.get(i)); //content from test.txt which is not there in test2.txt
}
System.out.println("content from test2.txt which is not there in test.txt");
tmpList = list2;
tmpList.removeAll(list1);
for(int i=0;i<tmpList.size();i++){
System.out.println(tmpList.get(i)); //content from test2.txt which is not there in test.txt
}
}
}

The memory will be a problem as you need to load both files into the program.
I am using HashSet to ignore duplicates.Try this:
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.HashSet;
public class FileReader1 {
public static void main(String args[]) {
String filename = "abc.txt";
String filename2 = "xyz.txt";
HashSet <String> al = new HashSet<String>();
HashSet <String> al1 = new HashSet<String>();
HashSet <String> diff1 = new HashSet<String>();
HashSet <String> diff2 = new HashSet<String>();
String str = null;
String str2 = null;
try {
BufferedReader in = new BufferedReader(new FileReader(filename));
while ((str = in.readLine()) != null) {
al.add(str);
}
in.close();
} catch (Exception e) {
e.printStackTrace();
}
try {
BufferedReader in = new BufferedReader(new FileReader(filename2));
while ((str2 = in.readLine()) != null) {
al1.add(str2);
}
in.close();
} catch (Exception e) {
e.printStackTrace();
}
for (String str3 : al) {
if (!al1.contains(str3)) {
diff1.add(str3);
}
}
for (String str5 : al1) {
if (!al.contains(str5)) {
diff2.add(str5);
}
}
for (String str4 : diff1) {
System.out.println("Removed Path: "+str4);
}
for (String str4 : diff2) {
System.out.println("Added Path: "+str4);
}
}
}
Output:
Removed Path: E:\Users\Documents\hello\b.properties
Added Path: E:\Users\Documents\hello\h.properties
Added Path: E:\Users\Documents\hello\g.properties

You can simple do follow
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
public class Test {
public static void main(final String[] args) throws IOException {
final Path firstFile = Paths.get("/home/src/main/resources/a.txt");
final Path secondFile = Paths.get("/home/src/main/resources/b.txt");
final List<String> firstFileContent = Files.readAllLines(firstFile,
Charset.defaultCharset());
final List<String> secondFileContent = Files.readAllLines(secondFile,
Charset.defaultCharset());
System.out.println(diffFiles(firstFileContent, secondFileContent));
System.out.println(diffFiles(secondFileContent, firstFileContent));
}
private static List<String> diffFiles(final List<String> firstFileContent,
final List<String> secondFileContent) {
final List<String> diff = new ArrayList<String>();
for (final String line : firstFileContent) {
if (!secondFileContent.contains(line)) {
diff.add(line);
}
}
return diff;
}
}

Compare files [Scanner and ArrayList]:
protected static void compareFiles(String firstFile, String secondFile)
throws Exception {
Scanner x = new Scanner(new File(firstFile));
List<String> list1 = getScannerList(x);
x = new Scanner(new File(secondFile));
List<String> list2 = getScannerList(x);
x.close();
System.out.println("File Extras");
printLnList(listExtras(list1, new ArrayList<String>(list2)));
System.out.println("File Removals");
printLnList(listExtras(list2, list1));
}
protected static List<String> listExtras(List<String> list1,
List<String> list2) throws Exception {
list2.removeAll(list1);
return list2;
}
protected static List<String> getScannerList(Scanner sc) throws Exception {
List<String> scannerList = new ArrayList<String>();
while (sc.hasNext())
scannerList.add(sc.nextLine());
return scannerList;
}
protected static void printLnList(List<String> list) {
for (String string : list)
System.out.println(string);
}
Program output:
File Extras
E:\Users\Documents\hello\g.properties
E:\Users\Documents\hello\h.properties
File Removals
E:\Users\Documents\hello\b.properties

Trying to read a text file using regex to check each line

I am trying to write a program that will allow a user to input a name of a movie and the program would then generate the date associated with. I have a text file that has date and the movies that pertain to it. I am reading the file via Scanner and I created a movie class that stores an ArrayList and String for movies and date, respectively. I am having trouble with reading the files. Can anyone please assist me. Thank you!
Here is a part of the text file:
10/1/2014
Der Anstandige
"Men, Women and Children"
Nas: Time is Illmatic
10/2/2014
Bang Bang
Haider
10/3/2014
Annabelle
Bitter Honey
Breakup Buddies
La chambre bleue
Drive Hard
Gone Girl
The Good Lie
A Good Marriage
The Hero of Color City
Inner Demons
Left Behind
Libertador
The Supreme Price
Here is my movie class
import java.util.ArrayList;
public class movie
{
private ArrayList<String> movies;
private String date;
public movie(ArrayList<String> movies, String date)
{
this.movies = movies;
this.date = date;
}
public String getDate()
{
return date;
}
public void setDate(String date)
{
this.date = date;
}
public ArrayList<String> getMovies()
{
return movies;
}
}
Here is the readFile class
package Read;
import java.util.List;
import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;
public class readFile
{
public static List<movie> movies;
public static String realPath;
public static ArrayList<String> mov;
public static String j;
public static String i;
public static void main(String[]args)
{
//movies = new ArrayList<movie>();
realPath = "movie_release_dates.txt";
File f = new File(realPath);
try
{
String regex1 = "[^(0-9).+]";
String regex2 = "[^0-9$]";
Scanner sc = new Scanner(f);
while (sc.hasNextLine())
{
System.out.println("Hello");
//movies
if(!sc.nextLine().matches(regex2))
{
i = sc.nextLine();
System.out.println("Hello2");
System.out.println(i);
}
//date
while(sc.nextLine().matches(regex1))
{
System.out.println("Hello3");
if(!sc.nextLine().matches(regex1))
{
j = sc.nextLine();
mov.add(sc.nextLine());
System.out.println("Hello4");
}
}
movie movie = new movie(mov,i);
movies.add(movie);
}
// sc.close();
}
catch(Exception e)
{
System.out.println("CANT");
}
}
}

You shouldn't be calling sc.nextLine () in every check. Every NextLine () call reads next line.This means that you are checking one line and processing next line

package com.stackoverflow.q26269799;
import java.util.List;
import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;
public class ReadFile {
public static List<Movie> movies = new ArrayList<Movie>();
public static String realPath;
public static ArrayList<String> mov;
public static String j;
public static String i;
public static void main(String[] args) {
//movies = new ArrayList<movie>();
realPath = "movie_release_dates.txt";
File f = new File(realPath);
if ( !f.exists()) {
System.err.println("file path not specified");
}
try {
String regex1 = "[^(0-9).+]";
String regex2 = "[^0-9$]";
Scanner sc = new Scanner(f);
while (sc.hasNextLine()) {
System.out.println("Hello");
// movies
String nextLine = sc.nextLine();
if (nextLine != null) {
if ( !nextLine.matches(regex2)) {
i = nextLine;
System.out.println("Hello2");
System.out.println(i);
}
// date
while (nextLine != null && nextLine.matches(regex1)) {
System.out.println("Hello3");
if ( !nextLine.matches(regex1)) {
j = nextLine;
mov.add(nextLine);
System.out.println("Hello4");
}
nextLine = sc.nextLine();
}
}
Movie movie = new Movie(mov, i);
movies.add(movie);
}
// sc.close();
} catch(Exception e) {
throw new RuntimeException(e);
}
}
}
This is needed: //movies = new ArrayList<movie>();
Every time you call nextLine it will move the scanner point to the next line. So call it once a time and check if it match those regex. String nextLine = sc.nextLine();
Please check you whether the file path is specified.

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
public class ReadFile
{
Map<String, String> movies;
public static void main(String[] args) throws IOException
{
ReadFile readFile = new ReadFile();
readFile.movies = new TreeMap<>();
try
{
readFile.importData();
printf(readFile.queryData("Der Anstandige"));
printf(readFile.queryData("Bitter"));
printf(readFile.queryData("blah"));
printf(readFile.queryData("the"));
}
catch(IOException e)
{
throw(e);
}
}
void importData() throws IOException, FileNotFoundException
{
LineNumberReader reader = null;
File file = new File("c:/movie_release_dates.txt");
try
{
reader = new LineNumberReader(new FileReader(file), 1024*64); //
String line;
String date = null, movie = null;
while((line = reader.readLine()) != null)
{
line = line.trim();
if(line.equals("")) continue;
if(line.matches(PATTERN_DATE))
{
date = line;
date = strf("%s/%s",
date.substring(date.length() - 4),
date.substring(0, date.length() - 5));
continue;
}
else
{
movie = line.trim();
}
movies.put(movie, date);
}
}
catch(FileNotFoundException e)
{
throw(e);
}
finally
{
reader.close();
}
}
String queryData(String title)
{
String regex = "(?i)" + title.replaceAll("\\s", "\\s+");
String[] matches = new String[movies.size()];
int i = 0; for(Entry<String , String> movie : movies.entrySet())
{
String key = movie.getKey();
String val = movie.getValue();
if(key.matches(regex))
{
matches[i++] = strf("{movie=%s, date=%s}", key, val);
}
else if(key.toUpperCase().trim()
.contains(title.toUpperCase().trim()))
{
matches[i++] = strf("{movie=%s, date=%s}", key, val);
}
}
String string = "";
if(matches[0] == null)
{
string = "Not found\n";
}
else
{
i = 0; while(matches[i] != null)
{
string += matches[i++] + "\n";
}
}
return string;
}
final String strf(String arg0, Object ... arg1)
{
return String.format(arg0, arg1);
}
final static void printf(String format, Object ... args)
{
System.out.printf(format, args);
}
final static void println(String x)
{
System.out.println(x);
}
final String PATTERN_DATE = "\\d{1,2}\\/\\d{1,2}\\/\\d{4}";
}
Console output:
{movie=Der Anstandige, date=2014/10/1}
{movie=Bitter Honey, date=2014/10/3}
Not found
{movie=The Good Lie, date=2014/10/3}
{movie=The Hero of Color City, date=2014/10/3}
{movie=The Supreme Price, date=2014/10/3}

Reading integers in .txt file and store in arraylist

I know this question might be answered many times. However, I still cannot solve this specific problem.
Basically I have a .txt file with the following format.
String Integer String
For example,
la 789 ferrari
turbo 560 porsche
veyron 987 bugatti
sls 563 benz
dbs 510 aston
How can I read the file line by line and store the numbers/integers ONLY into arraylist?
Thank you!

Here's a more full Java-esque solution, using Java 7 ... for fun.
Main.java
import java.util.List;
public class Main
{
private static final InputFileParser inputFileParser = new InputFileParser();
private static final EntryNumberExtractor extractor = new EntryNumberExtractor();
private static final String FILENAME = "input-file.txt";
public static void main(String... args)
{
List<Entry> entries = inputFileParser.parse(FILENAME);
List<Integer> extractedIntegers = extractor.extract(entries);
System.out.println("Entries: ");
prettyPrintListItems(entries);
System.out.println();
System.out.println("Entry numbers: ");
prettyPrintListItems(extractedIntegers);
}
private static <T> void prettyPrintListItems(List<T> list)
{
for (T item : list)
{
System.out.println(item);
}
}
}
InputFileParser.java
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class InputFileParser
{
public List<Entry> parse(String filename)
{
List<Entry> entries = new ArrayList<>();
File f = new File(filename);
try (BufferedReader reader = new BufferedReader(new FileReader(f));)
{
String line = null;
while ((line = reader.readLine()) != null)
{
String[] components = line.split(" ");
entries.add(new Entry(components[0], Integer.parseInt(components[1]), components[2]));
}
}
catch (IOException e)
{
e.printStackTrace();
}
return entries;
}
}
EntryNumberExtractor.java
import java.util.ArrayList;
import java.util.List;
public class EntryNumberExtractor
{
public List<Integer> extract(List<Entry> entries)
{
List<Integer> integers = new ArrayList<>();
for (Entry e : entries)
{
integers.add(e.getNumber());
}
return integers;
}
}
Entry.java
public class Entry
{
private String model;
private int number;
private String company;
public Entry(String model, int number, String company)
{
this.model = model;
this.number = number;
this.company = company;
}
public Integer getNumber()
{
return number;
}
#Override
public String toString()
{
return "model: " + model + ", number: " + number + ", company: " + company;
}
}

ArrayList<int> list = new ArrayList<int>();
try {
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
String line = br.readLine();
while(line != null)
{
String[] tokens = line.Split(" ");
list.Add(Integer.parseInt(tokens[1]));
line = br.readLine()
}
catch(Exception e)
{
//Probably a conversation exception or a index out of bounds exception
}

You can read each line and split the line string by space, retrieve the number and store it in array list

How to create a regex who verify the existence of a number into an array in java

i want to verify if a number for example 701234567 is an element of my array in java. For this, my code search if my number who is begening with 7 and have 9 digits is a element of my array "numbercall.txt" who have 5 elements. This is my text file:
numbercall.txt [ 702345678, 714326578, 701234567, 791234567,751234567]
This is my code:
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class TestNumberLt {
static String[] arr= null;
String filename = "fichiers/numbercall.txt";
static String a = null ;
static List<String> list = new ArrayList<String>();
public static void main(String [] args) throws IOException{
FileInputStream fstream_school = new FileInputStream(filename);
DataInputStream data_input = new DataInputStream(fstream_school);
BufferedReader buffer = new BufferedReader(new InputStreamReader(data_input));
String str_line;
while ((str_line = buffer.readLine()) != null)
{
str_line = str_line.trim();
if ((str_line.length()!=0))
{
list.add(str_line);
}
}
int b = 773214576;
//convert the arraylist to a array
arr = (String[])list.toArray(new String[list.size()]);
Pattern p = Pattern.compile("^7[0|6|7][0-9]{7}$");
Matcher m ;
//a loop for verify if a number exist in this array
for (int j = 0; j < list.size();)
{
System.out.print(" "+list.get(j)+ " ");
m = p.matcher(list.get(j));
/*while(m.find())
System.out.println(m.group());*/
if(list.get(j).equals(b))
{
System.out.println("Trouvé "+list.get(j));
break;
}
else
{
System.out.println("ce numéro ("+b+") n'existe pas!");
}
break;
}
}
}

Do it simply like this
String str_line= "702345678,714326578,701234567,791234567,751234567";
String[] strArray = str_line.split(",");
String key = "702345678";
for(String v:strArray) {
if(v.equals(key)) {
System.out.println("found");
}
}

I'm not realy sure of what you want, but if you just need the index of b in your array just do this:
public static void main(String [] args) throws IOException{
...
int b = 773214576;
int tmp = list.indexOf(b+"");
if(tmp!=-1) {
System.out.println("Trouvé "+ b + " à l'index " + tmp);
} else {
System.out.println("Ce numéro ("+b+") n'existe pas!");
}
...
}

Another answer, using Guava :
(in this case, there really is no need, you could simply use split() method from String object, but like Guava readibility and returns)
package stackoverflow;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import com.google.common.base.Splitter;
public class RegexExample {
String filename = "numbercall.txt";
public boolean isInList(String numberToCheck) throws IOException {
BufferedReader file = loadFile();
for (String number : extractNumberListFrom(file)) {
if (number.trim().equals(numberToCheck)) {
return true;
}
}
return false;
}
private Iterable<String> extractNumberListFrom(BufferedReader buffer) throws IOException {
StringBuilder numberList = new StringBuilder();
String line;
while ((line = buffer.readLine()) != null) {
numberList.append(line);
}
return Splitter.on(",").split(numberList.toString());
}
private BufferedReader loadFile() {
InputStream fstream_school = RegexExample.class.getResourceAsStream(filename);
BufferedReader buffer = new BufferedReader(new InputStreamReader(fstream_school));
return buffer;
}
}