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save single string to array separate by multi space in file text java

I'm a java beginner and I'm doing a small project about dictionary, now I want to save word and translate mean in file, because my native language often have space like chicken will be con gà so, I must use other way, not by space, but I really don't know how to do that, a word and it translation in one line, separate by "tab", mean multi space like chicken con gà now I want to get 2 words and store it in my array of Words which I created before, so I want to do something like
w1=word1inline;
w2=word2inline;
Word(word1inline,word2inline);(this is a member of array);
please help me, thanks a lot, I just know how to read line from file text, and use split to get word but I am not sure how to read by multi space.
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class docfile {
public static void main(String[] args)
{
String readLine;
ArrayList<String>str=new ArrayList<>(String);
try {
File file = new File("text.txt");
BufferedReader b = new BufferedReader(new FileReader(file));
while ((readLine = b.readLine()) != null) {
str.add()=readLine.split(" ");
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

If you stick to using tabs as a separator, this should work:
package Application;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class Application {
public static void main(String[] args) {
String line;
ArrayList<String> str = new ArrayList<>();
try {
File file = new File("text.txt");
BufferedReader b = new BufferedReader(new FileReader(file));
while ((line = b.readLine()) != null) {
for (String s : line.split("\t")) {
str.add(s);
}
}
str.forEach(System.out::println);
} catch (IOException e) {
e.printStackTrace();
}
}
}

Why not just use a properties file?
dict.properties:
chicken=con gá
Dict.java:
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Properties;
public class Dict {
public static void main(String[] args) throws IOException {
Properties dict = new Properties();
dict.load(Files.newBufferedReader(Paths.get("dict.properties")));
System.out.println(dict.getProperty("chicken"));
}
}
Output:
con gá

If your line is like this chicken con gà you can use indexof() method to find the first space in the string.
Then you can substring each word by using substring() method.
readLine = b.readLine();
ArrayList<String>str=new ArrayList<>();
int i = readLine.indexOf(' ');
String firstWord = readLine.substring(0, i);
String secondWord = readLine.substring(i+1, readLine.length());
str.add(firstWord);
str.add(secondWord);

getting stuck in replacing stopwords(txt.file) from data stored as list fetched from database

Kindly view code at for loop part where using replace method
I am Unable to replace stop words from data I have fetched from data base.
error shows ,array bound exception:1.
Kindly view code at for loop part where using replace method
I am Unable to replace stop words from data I have fetched from data base.
error shows ,array bound exception:1.
Kindly view code at for loop part where using replace method
I am Unable to replace stop words from data I have fetched from data base.
error shows ,array bound exception:1.
I amunable to resolve it ,give me some suggestion
package chatbot;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.Set;
import java.util.stream.IntStream;
public class keywords{
private static Scanner scan2;
private static final String driverName = "oracle.jdbc.driver.OracleDriver";
private static final String QUER = null;
//private static final String SCOR = null;
// private static final String SCORE =
private static final String ANSW = null;
public static void main(String[] args) throws IOException, SQLException {
Connection con = null;
Statement stmnt = null;
ResultSet result = null;
Set<String> list1= new HashSet<>();
try {
Class.forName(driverName);
con = DriverManager.getConnection("jdbc:oracle:thin:#10.144.97.144:1521:NQLDEV", "DEVNQL", "DEVNQL");
stmnt = con.createStatement();
System.out.println("Connection established");
List<String> rsl1 = new ArrayList<>();
List<String> rsl3 = new ArrayList<>();
String query = "SELECT * FROM DEVNQL.CHATKEY";
ResultSet rs = stmnt.executeQuery(query);
while (rs.next()) {
rsl1.add(rs.getString(1));
rsl3.add(rs.getString(3));
}
//System.out.println("result "+rsl1 + " "+rsl3);
File file = new File("M:\\Documents\\stop-word-list.txt");
BufferedReader br = new BufferedReader(new FileReader(file));
String st;
while((st=br.readLine()) != null){
ArrayList<String> wordList = new ArrayList<String>(Arrays.asList(st));
//List<String> ux = new ArrayList<>(Arrays.asList(st));
for(int i=0;i<rsl1.size()-1;i++){
for(String n:wordList)
if(rsl1.contains(n.getBytes()[i])){
rsl1.get(i).replace(n.charAt(i)+"\\rsl1+", "");
//note this will remove spaces at the end
}
}
System.out.println(rsl1);
}}
// for (int i=0;i<=rsl1.size()-1;i++){
/*
for (String removeword:wordList){
System.out.println("removeword "+removeword+ " "+rsl1.get(i)+
" "+rsl1.get(i).contains(removeword));
rsl1.get(i).replace("hi","abcd********");
if (rsl1.get(i).contains(removeword)) {
rsl1.get(i).replace("hi","abcd********");
} // end if
} // end for
*/ // } // end for
// System.out.println("result "+rsl1);
// }
// System.out.println("replace "+rsl1.get(0).replace("hi", "abcde"));
// }
catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.exit(1);
}
fi`enter code here`nally {
if (stmnt != null) {
stmnt.close();
}
if (con != null) {
con.close();
}
}
}}

replace actually returns a new String as in Java Strings are immutatable
so
String newString = rsl1.get(i).replace(n.charAt(i)+"\\rsl1+", "");

String line or StringTokenizer with a Reader?

I had a file to read and with this code I succeeded my JUnit tests. As you can see, I pass the String line as parameter to the readPrevisione(...) method.
package oroscopo.persistence;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.StringTokenizer;
import oroscopo.model.Previsione;
import oroscopo.model.SegnoZodiacale;
public class TextFileOroscopoRepository implements OroscopoRepository {
private HashMap<String, List<Previsione>> mapSettore = new HashMap<>();
public TextFileOroscopoRepository(Reader baseReader) throws IOException, BadFileFormatException{
if (baseReader == null)
throw new IllegalArgumentException("baseReader is null");
BufferedReader bufReader = new BufferedReader(baseReader);
String line;
while((line=bufReader.readLine()) != null){
readPrevisione(line,bufReader);
}
}
private void readPrevisione(String line, BufferedReader bufReader) throws IOException, BadFileFormatException{
String nomeSettore = line.trim();
if (!Character.isUpperCase(nomeSettore.charAt(0)))
throw new BadFileFormatException();
List<Previsione> listaPrev = new ArrayList<>();
while (!(line = bufReader.readLine()).equalsIgnoreCase("FINE")){
try{
StringTokenizer st1 = new StringTokenizer(line, "\t");
if(st1.countTokens() < 2)
throw new BadFileFormatException();
String prev = st1.nextToken("\t").trim();
int val = Integer.parseInt(st1.nextToken("\t").trim());
Set<SegnoZodiacale> segni = new HashSet<>();
if (st1.hasMoreTokens()){
while(st1.hasMoreTokens()){
try{
segni.add(SegnoZodiacale.valueOf(st1.nextToken(",").trim()));
}
catch (IllegalArgumentException e){
throw new BadFileFormatException();
}
}
Previsione p = new Previsione(prev,val,segni);
listaPrev.add(p);
}
else{
Previsione p2 = new Previsione(prev,val);
listaPrev.add(p2);
}
}
catch (NumberFormatException e){
throw new BadFileFormatException();
}
catch (NoSuchElementException e){
throw new BadFileFormatException();
}
}
mapSettore.put(nomeSettore, listaPrev);
}
#Override
public Set<String> getSettori() {
return mapSettore.keySet();
}
#Override
public List<Previsione> getPrevisioni(String settore) {
return mapSettore.get(settore.toUpperCase());
}
}
Here with the same code, instead passing the read line as parameter, I pass the StringTokenizer that already has read the line. It should work like above but my JUnit tests fail. What did I do wrong?
package oroscopo.persistence;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.StringTokenizer;
import oroscopo.model.Previsione;
import oroscopo.model.SegnoZodiacale;
public class TextFileOroscopoRepository implements OroscopoRepository {
private HashMap<String, List<Previsione>> mapSettore = new HashMap<>();
public TextFileOroscopoRepository(Reader baseReader) throws IOException, BadFileFormatException{
if (baseReader == null)
throw new IllegalArgumentException("baseReader is null");
BufferedReader bufReader = new BufferedReader(baseReader);
String line;
while((line=bufReader.readLine()) != null){
StringTokenizer st = new StringTokenizer(line);
readPrevisione(st,bufReader);
}
}
private void readPrevisione(StringTokenizer st, BufferedReader bufReader) throws IOException, BadFileFormatException{
String nomeSettore = st.nextToken().trim();
if (!Character.isUpperCase(nomeSettore.charAt(0)))
throw new BadFileFormatException();
List<Previsione> listaPrev = new ArrayList<>();
String line;
while (!(line = bufReader.readLine()).equalsIgnoreCase("FINE")){
try{
StringTokenizer st1 = new StringTokenizer(line, "\t");
if(st1.countTokens() < 2)
throw new BadFileFormatException();
String prev = st1.nextToken("\t").trim();
int val = Integer.parseInt(st1.nextToken("\t").trim());
Set<SegnoZodiacale> segni = new HashSet<>();
if (st1.hasMoreTokens()){
while(st1.hasMoreTokens()){
try{
segni.add(SegnoZodiacale.valueOf(st1.nextToken(",").trim()));
}
catch (IllegalArgumentException e){
throw new BadFileFormatException();
}
}
Previsione p = new Previsione(prev,val,segni);
listaPrev.add(p);
}
else{
Previsione p2 = new Previsione(prev,val);
listaPrev.add(p2);
}
}
catch (NumberFormatException e){
throw new BadFileFormatException();
}
catch (NoSuchElementException e){
throw new BadFileFormatException();
}
}
mapSettore.put(nomeSettore, listaPrev);
}
#Override
public Set<String> getSettori() {
return mapSettore.keySet();
}
#Override
public List<Previsione> getPrevisioni(String settore) {
return mapSettore.get(settore.toUpperCase());
}
}
EDIT: Here is the File.txt that I want to read.
And here is an example of one of my JUnit test:
#Test
public void testLetturaCorrettaPrevisioni1() throws IOException, BadFileFormatException {
Reader mr = new StringReader(
"NOMESEZIONE\navrai la testa un po' altrove\t\t4\tARIETE,TORO,GEMELLI\ngrande intimita'\t9\nFINE\n"
+ "SEZIONE2\ntesto di prova\t\t\t\t\t66\t\nFINE");
OroscopoRepository or = new TextFileOroscopoRepository(mr);
assertEquals("avrai la testa un po' altrove", or.getPrevisioni("nomesezione").get(0).getPrevisione());
assertEquals(4, or.getPrevisioni("nomesezione").get(0).getValore());
Set<SegnoZodiacale> validi = new HashSet<SegnoZodiacale>() {
private static final long serialVersionUID = 1L;
{
add(SegnoZodiacale.ARIETE);
add(SegnoZodiacale.TORO);
add(SegnoZodiacale.GEMELLI);
}
};
for (SegnoZodiacale s : SegnoZodiacale.values()) {
if (validi.contains(s))
assertTrue(or.getPrevisioni("nomesezione").get(0).validaPerSegno(s));
else
assertFalse(or.getPrevisioni("nomesezione").get(0).validaPerSegno(s));
}
assertEquals("grande intimita'", or.getPrevisioni("nomesezione").get(1).getPrevisione());
assertEquals(9, or.getPrevisioni("nomesezione").get(1).getValore());
for (SegnoZodiacale s : SegnoZodiacale.values()) {
assertTrue(or.getPrevisioni("nomesezione").get(1).validaPerSegno(s));
}
}

You are creating StringTokenizer with default delimiter, that is, "the space character, the tab character, the newline character, the carriage-return character, and the form-feed character."
So in the first case you set as value of the "nomeSettore" variable the whole line but when you use StringTokenizer.nextToken() you are giving to "nomeSettore" just the value of the first token. So, "nomeSettore" can have different values if your String "line" contains whitespaces and you will have different key-value pairs inside you map.
You can take a look at this example:
public class TestSO {
public static void main(String[] args) {
String line = "abcdfs faf afd fa";
StringTokenizer st = new StringTokenizer(line);
readPrevisione(st, null);
readPrevisione(line, null);
}
private static void readPrevisione(StringTokenizer st, BufferedReader bufReader) {
String nomeSettore = st.nextToken().trim();
System.out.println(nomeSettore);
}
private static void readPrevisione(String st, BufferedReader bufReader) {
String nomeSettore = st.trim();
System.out.println(nomeSettore);
}
}
It prints as output:
abcdfs
abcdfs faf afd fa

I've understood why it didn't work..
The String line was : "EXAMPLE\n"
but after
while((line=bufReader.readLine()) != null){
...}
line = "EXAMPLE" because the readLine() eats the newline.
So I passed to the readPrevisione() a StringTokenizer as parameter
while((line=bufReader.readLine()) != null){
StringTokenizer st = new StringTokenizer(line);
readPrevisione(st,bufReader);
}
private void readPrevisione(StringTokenizer st, BufferedReader bufReader) throws IOException, BadFileFormatException{
String nomeSettore = st.nextToken().trim();
...}
And st.nextToken() search for a \n that is not contained in "EXAMPLE". That's why it didn't work.

MongoDB NULL Pointer Exception while getting JSON as input

package com.demo.mongodb;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.util.JSON;
public class Driver {
private static DBCollection channelDBcollection;
public static void main(String[] args) throws IOException {
DB db = (new MongoClient("localhost",27017)).getDB("demo");
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
boolean flag = false;
while(!flag) flag = autenticate(db, bufferedReader);
}
private static boolean autenticate(DB db, BufferedReader bufferedReader) throws IOException{
boolean flag = true;
System.out.println("User: ");
String user = bufferedReader.readLine();
System.out.println("Password: ");
String password = bufferedReader.readLine();
if(db.authenticate(user, password.toCharArray())){
DBCollection channDbCollection = db.getCollection("Channel");
String command = null;
while(true){
System.out.println("What do you want to do ? ");
command = bufferedReader.readLine();
if(command.equals("exit")) break ;
else if(command.equals("findALL")) findAll(channDbCollection);
else if(command.equals("insertJSON")) insertJSON(bufferedReader,channDbCollection);
}
}
else{
System.out.println("invalid user/password");
flag = false;
}
return flag;
}
private static void findAll(DBCollection dbCollection){
DBCursor dbCursor = channelDBcollection.find();
while(dbCursor.hasNext()) System.out.println(dbCursor.next());
}
private static void insertJSON(BufferedReader bufferedReader,DBCollection channDbCollection) throws IOException {
System.out.println("JSON: ");
channDbCollection.insert((DBObject) JSON.parse(bufferedReader.readLine()));
}
}
I make Database in MongoDB like :-
use demo
db.addUser("root","root")
While i executed application then while i enter for JSON , i found null pointer can someone help me to take out of this ?

in your
private static void findAll(DBCollection dbCollection){
DBCursor dbCursor = channelDBcollection.find();
while(dbCursor.hasNext()) System.out.println(dbCursor.next());
}
function, you use global variable channelDBcollection (which is null at the time of call) instead of parameter dbCollection (which is not used anywhere in the method);
what you think is "not null" is the local variable with confusing name "channDbCollection", but it's not used anywhere;
I suggest you to revise your approach to naming, using global variables and coding style in general.

Remove Duplicate Lines from Text using Java

I was wondering if anyone has logic in java that removes duplicate lines while maintaining the lines order.
I would prefer no regex solution.

public class UniqueLineReader extends BufferedReader {
Set<String> lines = new HashSet<String>();
public UniqueLineReader(Reader arg0) {
super(arg0);
}
#Override
public String readLine() throws IOException {
String uniqueLine;
if (lines.add(uniqueLine = super.readLine()))
return uniqueLine;
return "";
}
//for testing..
public static void main(String args[]) {
try {
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(
"test.txt");
UniqueLineReader br = new UniqueLineReader(new InputStreamReader(fstream));
String strLine;
// Read File Line By Line
while ((strLine = br.readLine()) != null) {
// Print the content on the console
if (strLine != "")
System.out.println(strLine);
}
// Close the input stream
in.close();
} catch (Exception e) {// Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
}
Modified Version:
public class UniqueLineReader extends BufferedReader {
Set<String> lines = new HashSet<String>();
public UniqueLineReader(Reader arg0) {
super(arg0);
}
#Override
public String readLine() throws IOException {
String uniqueLine;
while (lines.add(uniqueLine = super.readLine()) == false); //read until encountering a unique line
return uniqueLine;
}
public static void main(String args[]) {
try {
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(
"/home/emil/Desktop/ff.txt");
UniqueLineReader br = new UniqueLineReader(new InputStreamReader(fstream));
String strLine;
// Read File Line By Line
while ((strLine = br.readLine()) != null) {
// Print the content on the console
System.out.println(strLine);
}
// Close the input stream
in.close();
} catch (Exception e) {// Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
}

If you feed the lines into a LinkedHashSet, it ignores the repeated ones, since it's a set, but preserves the order, since it's linked. If you just want to know whether you've seena given line before, feed them into a simple Set as you go on, and ignore those which the Set already contains/contained.

It can be easy to remove duplicate line from text or File using new java Stream API. Stream support different aggregate feature like sort,distinct and work with different java's existing data structures and their methods. Following example can use to remove duplicate or sort the content in File using Stream API
package removeword;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.Stream;
import static java.nio.file.StandardOpenOption.*;
import static java.util.stream.Collectors.joining;
public class Java8UniqueWords {
public static void main(String[] args) throws IOException {
Path sourcePath = Paths.get("C:/Users/source.txt");
Path changedPath = Paths.get("C:/Users/removedDouplicate_file.txt");
try (final Stream<String> lines = Files.lines(sourcePath )
// .map(line -> line.toLowerCase()) /*optional to use existing string methods*/
.distinct()
// .sorted()) /*aggregrate function to sort disctincted line*/
{
final String uniqueWords = lines.collect(joining("\n"));
System.out.println("Final Output:" + uniqueWords);
Files.write(changedPath , uniqueWords.getBytes(),WRITE, TRUNCATE_EXISTING);
}
}
}

Read the text file using a BufferedReader and store it in a LinkedHashSet. Print it back out.
Here's an example:
public class DuplicateRemover {
public String stripDuplicates(String aHunk) {
StringBuilder result = new StringBuilder();
Set<String> uniqueLines = new LinkedHashSet<String>();
String[] chunks = aHunk.split("\n");
uniqueLines.addAll(Arrays.asList(chunks));
for (String chunk : uniqueLines) {
result.append(chunk).append("\n");
}
return result.toString();
}
}
Here's some unit tests to verify ( ignore my evil copy-paste ;) ):
import org.junit.Test;
import static org.junit.Assert.*;
public class DuplicateRemoverTest {
#Test
public void removesDuplicateLines() {
String input = "a\nb\nc\nb\nd\n";
String expected = "a\nb\nc\nd\n";
DuplicateRemover remover = new DuplicateRemover();
String actual = remover.stripDuplicates(input);
assertEquals(expected, actual);
}
#Test
public void removesDuplicateLinesUnalphabetized() {
String input = "z\nb\nc\nb\nz\n";
String expected = "z\nb\nc\n";
DuplicateRemover remover = new DuplicateRemover();
String actual = remover.stripDuplicates(input);
assertEquals(expected, actual);
}
}

Here's another solution. Let's just use UNIX!
cat MyFile.java | uniq > MyFile.java
Edit: Oh wait, I re-read the topic. Is this a legal solution since I managed to be language agnostic?

For better/optimum performance, it's wise to use Java 8's API features viz. Streams & Method references with LinkedHashSet for Collection as below:
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.LinkedHashSet;
import java.util.stream.Collectors;
public class UniqueOperation {
private static PrintWriter pw;
enter code here
public static void main(String[] args) throws IOException {
pw = new PrintWriter("abc.txt");
for(String p : Files.newBufferedReader(Paths.get("C:/Users/as00465129/Desktop/FrontEndUdemyLinks.txt")).
lines().
collect(Collectors.toCollection(LinkedHashSet::new)))
pw.println(p);
pw.flush();
pw.close();
System.out.println("File operation performed successfully");
}

here I'm using a hashset to store seen lines
Scanner scan;//input
Set<String> lines = new HashSet<String>();
StringBuilder strb = new StringBuilder();
while(scan.hasNextLine()){
String line = scan.nextLine();
if(lines.add(line)) strb.append(line);
}