I wrote this method, which is never ending. It isn't printing what I'm passing, why?
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
class Main {
public void readFromConsole() {
ArrayList<String> wholeInput= new ArrayList <String>();
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
try {
String line = null;
while (!(line = br.readLine()).equals(" ")){
wholeInput.add(line);
}
}
catch(IOException e){
e.printStackTrace();
}
for (int i =0; i<wholeInput.size();i++){
System.out.println(wholeInput.get(i));
}
}
}
" " is not an empty line, it is a space. Try ""
while (!(line = br.readLine()).trim().equals("")){
Related
In my below code I wanted to replace the text "DEMO" with "Demographics" but instead of replacing the text it deletes the entire content of the text file.
Contents inside the file:
DEMO
data
morning
PS: I'm a beginner in java
package com.replace.main;
import java.io.*;
public class FileEdit {
public static void main(String[] args) {
BufferedReader br = null;
BufferedWriter bw = null;
String readLine, replacedData;
try {
bw = new BufferedWriter(
new FileWriter(
"Demg.ctl"));
br = new BufferedReader(
new FileReader(
"Demg.ctl"));
System.out.println(br.readLine()); //I Get Null Printed Here
while ((readLine = br.readLine())!= null) {
System.out.println("Inside While Loop");
System.out.println(readLine);
if (readLine.equals("DEMO")) {
System.out.println("Inside if loop");
replacedData = readLine.replaceAll("DEMO","Demographics");
}
}
System.out.println("After While");
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
You open a Writer to your file, but you don't write anything. This means that your file is replaced with an empty file.
Besides this you also need to close your writer, not just the reader.
And last but not least, your if condition is wrong.
if (readLine.equals("DEMO")) {
should read
if (readLine.contains("DEMO")) {
Otherwise it would only return true if your line contained "DEMO" but nothing else.
I'm updating the answer to my own question.
package com.replace.main;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class FileEdit
{
public static void main(String args[])
{
try
{
BufferedReader reader = new BufferedReader(new FileReader("Demg.ctl"));
String readLine = "";
String oldtext = "";
while((readLine = reader.readLine()) != null)
{
oldtext += readLine + "\r\n";
}
reader.close();
// To replace the text
String newtext = oldtext.replaceAll("DEMO", "Demographics");
FileWriter writer = new FileWriter("Demg.ctl");
writer.write(newtext);
writer.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
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.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class part2
{
#SuppressWarnings("resource")
public static void main(String[] args) throws IOException
{
File f1 = new File("one.txt");
File f2 = new File("two.txt");
BufferedReader fr1 = null;
BufferedReader fr2 = null;
//BufferedReader fr3 = null;
BufferedWriter fw = null;
fr1 = new BufferedReader(new FileReader("one.txt"));
fr2 = new BufferedReader(new FileReader("two.txt"));
fw = new BufferedWriter(new FileWriter("res.txt"));
String line1 = fr1.readLine();
String line2 = fr2.readLine();
// merging two files into one
while (line1 != null)
{
fw.write(line1);
fw.newLine();
line1 = fr1.readLine();
}
while (line2 != null)
{
fw.write(line2);
fw.newLine();
line2= fr2.readLine();
}
fw.close();
// sorting a new file
BufferedReader fr3 = null;
BufferedWriter fw1 = null;
fw1 = new BufferedWriter(new FileWriter("res1.txt"));
fr3 = new BufferedReader(new FileReader("res.txt"));
String line3 = fr3.readLine();
ArrayList<String> lineList = new ArrayList<String>();
while (line3 != null)
{
lineList.add(line3);
line3 = fr3.readLine();
}
Collections.sort(lineList);
for(int i=0; i<lineList.size(); i++)
{
fw1.write(lineList.get(i) + "\n");
//line3 = fr3.readLine();
}
}
}
I'm trying to merge two files together into "res.txt", and then sort the merged file alphabetically (and put the sorted lines in "res1.txt"). Everything works until the sorting, to be exact from the while (line3 != null) line, i.e. it reads and merges two files, but doesn't sort them. Any ideas?
Close fw1 prior to exiting the program or it gets removed from memory before the content of the buffer is flushed.
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
public class Test {
List<String> knownWordsArrayList = new ArrayList<String>();
List<String> wordsArrayList = new ArrayList<String>();
List<String> newWordsArrayList = new ArrayList<String>();
String toFile = "";
public void readKnownWordsFile() {
try {
FileInputStream fstream2 = new FileInputStream("knownWords.txt");
BufferedReader br2 = new BufferedReader(new InputStreamReader(fstream2, "UTF-8"));
String strLine;
while ((strLine = br2.readLine()) != null) {
knownWordsArrayList.add(strLine.toLowerCase());
}
HashSet h = new HashSet(knownWordsArrayList);
// h.removeAll(knownWordsArrayList);
knownWordsArrayList = new ArrayList<String>(h);
// for (int i = 0; i < knownWordsArrayList.size(); i++) {
// System.out.println(knownWordsArrayList.get(i));
// }
} catch (Exception e) {
// TODO: handle exception
}
}
public void readFile() {
try {
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream("Smallville 4x02.de.srt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
String numberedLineRemoved = "";
String strippedInput = "";
String[] words;
String trimmedString = "";
String temp = "";
// Read File Line By Line
while ((strLine = br.readLine()) != null) {
temp = strLine.toLowerCase();
// Print the content on the console
numberedLineRemoved = numberedLine(temp);
strippedInput = numberedLineRemoved.replaceAll("\\p{Punct}", "");
if ((strippedInput.trim().length() != 0) || (!strippedInput.contains("")) || (strippedInput.contains(" "))) {
words = strippedInput.split("\\s+");
for (int i = 0; i < words.length; i++) {
if (words[i].trim().length() != 0) {
wordsArrayList.add(words[i]);
}
}
}
}
HashSet h = new HashSet(wordsArrayList);
h.removeAll(knownWordsArrayList);
newWordsArrayList = new ArrayList<String>(h);
// HashSet h = new HashSet(wordsArrayList);
// wordsArrayList.clear();
// newWordsArrayList.addAll(h);
for (int i = 0; i < newWordsArrayList.size(); i++) {
toFile = newWordsArrayList.get(i) + ".\n";
// System.out.println(newWordsArrayList.get(i) + ".");
System.out.println();
}
System.out.println(newWordsArrayList.size());
// Close the input stream
in.close();
} catch (Exception e) {// Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
public String numberedLine(String string) {
if (string.matches(".*\\d.*")) {
return "";
} else {
return string;
}
}
public void writeToFile() {
try {
// Create file
FileWriter fstream = new FileWriter("out.txt");
BufferedWriter out = new BufferedWriter(fstream);
out.write(toFile);
// Close the output stream
out.close();
} catch (Exception e) {// Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
public static void main(String[] args) {
Test test = new Test();
test.readKnownWordsFile();
test.readFile();
test.writeToFile();
}
}
How can I read äöüß from file?
Would the string.toLowercase() handle these properly as well?
And when I go to print words containing any of äöüß, how can I print the word properly?
When I print to console I get
Außerdem
weiß
for Außerdem
weiß
How can I fix this?
I tried:
BufferedReader br = new BufferedReader(new InputStreamReader(in, "UTF-8"));
But now I'm getting aufkl?ren instead of aufklären and its messing up in other places as well.
Updated the code to see if it would print on the file properly, but I'm just getting one in the file.
You need to read files using the charset which was used to create the file. If you're on a windows machine, that's probably cp1252. So:
BufferedReader br = new BufferedReader(new InputStreamReader(in, "Cp1252"));
If that doesn't work, most text editors are capable of telling you what encoding is used for a given document.
When trying to create two methods for counting the no. of rows and reading the values of a file, only one of these methods got executed and another is not executed showing the following error :Exception in thread "main" java.lang.RuntimeException: java.io.IOException: Read error
Please look at the following code:
package com.ibm.csvreader;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.io.*;
public class CsvFileReader2 {
public static class opencsvfile {
HashMap <String , String> map= new HashMap <String, String> ();
//csv file containing data
// FileReader strFile = new FileReader("C:/Users/vmuser/Desktop/SampleUpload.csv");
//create BufferedReader to read csv file
// BufferedReader br = new BufferedReader((strFile));
String strLine = "";
int lineNumber ;
public void countrows(FileInputStream fstream) throws Exception{
DataInputStream strFile = new DataInputStream(fstream);
BufferedReader br = new BufferedReader( new InputStreamReader (strFile));
lineNumber =0;
while( (strLine = br.readLine()) != null) {
lineNumber++;
}
System.out.println("no.of rows are :" +lineNumber);
br.close();
}
public void readfile(FileInputStream fstream) throws Exception{
DataInputStream strFile = new DataInputStream(fstream);
BufferedReader br = new BufferedReader( new InputStreamReader (strFile));
lineNumber =0;
while( (strLine = br.readLine()) != null) {
lineNumber++;
String[] tokens = strLine.split(",");
String key = tokens[0].trim();
String nodes = tokens[1].trim();
map.put(key, nodes);
}
System.out.println("map is" + map );
br.close();
System.out.println("File is Closed");
}
}
public static void main(String[] args) throws IOException {
File fl = new File ("C:/Users/vmuser/Desktop/SampleUpload.csv");
FileInputStream fstream = new FileInputStream(fl);
opencsvfile f=new opencsvfile();
try {
f.countrows(fstream);
f.readfile(fstream);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}
Just a small modification will do the work:
package com.ibm.csvreader;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.io.*;
public class CsvFileReader2 {
public static class opencsvfile {
HashMap <String , String> map= new HashMap <String, String> ();
//csv file containing data
// FileReader strFile = new FileReader("C:/Users/vmuser/Desktop/SampleUpload.csv");
//create BufferedReader to read csv file
// BufferedReader br = new BufferedReader((strFile));
String strLine = "";
int lineNumber ;
public void countrows(FileInputStream fstream) throws Exception{
DataInputStream strFile = new DataInputStream(fstream);
BufferedReader br = new BufferedReader( new InputStreamReader (strFile));
lineNumber =0;
while( (strLine = br.readLine()) != null) {
lineNumber++;
}
System.out.println("no.of rows are :" +lineNumber);
br.close();
}
public void readfile(FileInputStream fstream) throws Exception{
DataInputStream strFile = new DataInputStream(fstream);
BufferedReader br = new BufferedReader( new InputStreamReader (strFile));
lineNumber =0;
while( (strLine = br.readLine()) != null) {
lineNumber++;
String[] tokens = strLine.split(",");
String key = tokens[0].trim();
String nodes = tokens[1].trim();
map.put(key, nodes);
}
System.out.println("map is" + map );
br.close();
System.out.println("File is Closed");
}
}
public static void main(String[] args) throws IOException {
File fl = new File ("C:/Users/vmuser/Desktop/SampleUpload.csv");
FileInputStream fstream = new FileInputStream(fl);
opencsvfile f=new opencsvfile();
try {
f.countrows(fstream);
fstream = new FileInputStream(fl);//include this line
f.readfile(fstream);
} catch (Exception e) {
throw new RuntimeException(e);
}
finally{
if(fstream!=null)
fstream.close();//be sure to close all streams at last
}
}
}
Close all other streams as well. Above code will work for you.Cheers.
When you close your BufferedReader, it also closes the nested classes, including the FileInputStream.
Instead of closing it, you should try and reset() it to restart reading it from the start.
Or you must re-open the FileInputStream.
I am trying to read in a technical paper, separate all the sentences, use a filter to find key terms and phrases in the sentences, and then create my own abstract.
What I have so far is two BufferedReaders reading a text file with a paragraph in it, and my filter being read in. Each line is then being stored into an ArrayList and printed to the console to test if they are being read correctly.
I want to know if I am approaching this the correct way by using a BufferedReader instead of a Scanner. I just want to be able to print out all the sentences after a '.' (dot), a '!' (exclamation-point), or a '?' (question-mark) for right now, so I know that the file is being read correctly.
This is my code so far:
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.io.*;
import java.util.Scanner;
public class Filtering {
public static void main(String[] args) throws IOException {
ArrayList<String> lines1 = new ArrayList<String>();
ArrayList<String> lines2 = new ArrayList<String>();
try {
FileInputStream fstream1 = new FileInputStream("paper.txt");
FileInputStream fstream2 = new FileInputStream("filter2.txt");
DataInputStream inStream1 = new DataInputStream (fstream1);
DataInputStream inStream2 = new DataInputStream (fstream2);
BufferedReader br1 = new BufferedReader(
new InputStreamReader(inStream1));
BufferedReader br2 = new BufferedReader(
new InputStreamReader(inStream2));
String strLine1;
String strLine2;
while ((strLine1 = br1.readLine()) != null) {
lines1.add(strLine1);
}
while ((strLine2 = br2.readLine()) != null) {
lines2.add(strLine2);
}
inStream1.close();
inStream2.close();
}
catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
System.out.println(lines1);
System.out.println(lines2);
}
}
It is a good practice to use a BufferedReader to read any File as it will buffer the File instead of accessing each bytes one by one
The DataInputStream is not needed
You should specify a character encoding in your InputStreamReader
You could accumulate all your string in a StringBuilder so that you have the whole text in a single reference
You may want to look into BreakIterator to split your text into sentences. Have a look at getSentenceInstance().
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.BreakIterator;
public class Filtering {
public static void main(String[] args) throws IOException {
File paperFile = new File("paper.txt");
File filterFile = new File("filter2.txt");
// If you want you could roughly initiate the stringbuilders to their
// approximate future size
StringBuilder paper = new StringBuilder();
StringBuilder filter2 = new StringBuilder();
FileInputStream fstream1 = null;
FileInputStream fstream2 = null;
try {
fstream1 = new FileInputStream(paperFile);
fstream2 = new FileInputStream(filterFile);
BufferedReader br1 = new BufferedReader(new InputStreamReader(fstream1, "UTF-8"));
BufferedReader br2 = new BufferedReader(new InputStreamReader(fstream2, "UTF-8"));
String strLine1;
String strLine2;
while ((strLine1 = br1.readLine()) != null) {
paper.append(strLine1).append('\n');
}
while ((strLine2 = br2.readLine()) != null) {
filter2.append(strLine2).append('\n');
}
}
catch (Exception e) {
System.err.println("Error: " + e.getMessage());
} finally {
if (fstream1 != null) {
fstream1.close();
}
if (fstream2 != null) {
fstream2.close();
}
}
String paperString = paper.toString();
String filterString = filter2.toString();
System.out.println(paperString);
System.out.println(filterString);
// To break it into sentences
BreakIterator boundary = BreakIterator.getSentenceInstance();
boundary.setText(paperString);
int start = boundary.first();
for (int end = boundary.next(); end != BreakIterator.DONE; start = end, end = boundary.next()) {
System.out.println(paper.substring(start, end));
}
}
}