Develop Reference

How to read text file without the headline into ArrayList

I'm currently working on an assignment and I cannot find any clue to remove the headline from the text file and write the rest into an ArrayList. Can someone help me?
ID,Nama,GajiPokok,JmlAbsensi,JmlIzin
2,Peter,5000000,17,3
1,John,4500000,19,1
3,Linda,10000000,13,7
4,Lucy,7000000,20,0
Here is my code:
BufferedReader in = new BufferedReader(new FileReader("D:\\" + args[0] + ".txt"));
try {
String line = in.readLine();
String data[];
while (line != null){
data = line.split(",");
Staff s = new Staff(){};
s.setID(Integer.parseInt(data[0]));
s.setNama(data[1]);
s.setGajiPokok(Long.parseLong(data[2]));
s.setjmlhAbsensi(Integer.parseInt(data[3]));
s.setjmlhIzin(Integer.parseInt(data[4]));
s.getID();
s.getNama();
s.getGajiPokok();
s.getjmlhAbsensi();
s.getjmlhIzin();
list_Staff.addAll(Arrays.asList(s));
line = in.readLine();
}
in.close();
} catch (IOException e){e.printStackTrace();}

If you want to ignore first line while reading the CSV file then you can simple skip processing of 1st line by calling in.readLine(); twice at the start as shown in below example:
BufferedReader in = new BufferedReader(new FileReader("D:\\" + args[0] + ".txt"));
String line = in.readLine();
line = in.readLine(); //skip fist line and read second line
String data[];
while (line != null){
data = line.split(",");
Staff s = new Staff(){};
s.setID(Integer.parseInt(data[0]));
s.setNama(data[1]);
s.setGajiPokok(Long.parseLong(data[2]));
s.setjmlhAbsensi(Integer.parseInt(data[3]));
s.setjmlhIzin(Integer.parseInt(data[4]));
s.getID();
s.getNama();
s.getGajiPokok();
s.getjmlhAbsensi();
s.getjmlhIzin();
list_Staff.addAll(Arrays.asList(s));
line = in.readLine();
}
Using skip() method of JAVA 8 Streams:
try(BufferedReader in = new BufferedReader(new FileReader("D:\\" + args[0] + ".txt"))) {
Stream<String> lines = in.lines();
List<Staff> staff = lines.skip(1).map(line -> {
Staff s = new Staff();
String data[] = line.split(",");
s.setID(Integer.parseInt(data[0]));
s.setNama(data[1]);
s.setGajiPokok(Long.parseLong(data[2]));
s.setJmlhAbsensi(Integer.parseInt(data[3]));
s.setJmlhIzin(Integer.parseInt(data[4]));
return s;
}).collect(Collectors.toList());
System.out.println(staff);
}

You can declare the following line twice or initialize integer variable and skip the loop if its zero.
String line = in.readLine();

This solution works.
private void readTextFile(String fileName) throws FileNotFoundException {
BufferedReader in = new BufferedReader(new FileReader(fileName));
Stream<String> stream = in.lines();
List<String> answer = stream.collect(Collectors.toList());
// For Pre-Java8
/*for (int i = 1; i < answer.size(); i++) {
System.out.println(answer.get(i));
}*/
// Split afterwards.
Stream<String> ans = answer.stream().filter(p -> !p.equals(answer.get(0)));
ans.forEach(x -> System.out.println(x));
}

How to append multiple text in text file

I want the results from 'name' and 'code' to be inserted into log.txt file, but if I run this program only the name results gets inserted into .txt file, I cannot see code results appending under name. If I do System.outprintln(name) & System.outprintln(code) I get results printed in console but its not being inserted in a file.Can someone tell me what am I doing wrong?
Scanner sc = new Scanner(file, "UTF-8");
BufferedReader br = new BufferedReader(new FileReader(file));
PrintWriter out = new PrintWriter(new FileWriter("log.txt", true));
while ((line = br.readLine()) != null) {
if (line.contains("text1")) {
String[] splits = line.split("=");
String name = splits[2];
for (int i = 0; i < name.length(); i++) {
out.println(name);
}
}
if (line.contains("text2")) {
String[] splits = line.split("=");
String code = splits[2];
for (int i = 0; i < code.length(); i++) {
out.println(code);
}
}
out.close()
}
File looks like:
Name=111111111
Code=333,5555
Category-Warranty
Name=2222222
Code=111,22
Category-Warranty

Have a look at this code. Does that work for you?
final String NAME = "name";
final String CODE = "code";
BufferedReader br = new BufferedReader(new FileReader(file));
PrintWriter out = new PrintWriter(new FileWriter("log.txt", true));
while ((line = br.readLine()) != null) {
String[] splits = line.split("=");
String key = splits[0];
String value = splits[1];
if (key.equals(NAME) || key.equals(CODE)) {
out.println(value);
}
}
out.close();
You have a couple of problems in your code:
you never actually assign the variables name and code.
you close() your PrintWriter inside the while-loop, that means you will have a problem if you read more than one line.

I don't see why this wouldn't work, without seeing more of what you are doing:
BufferedReader br = new BufferedReader(new FileReader(file));
PrintWriter out = new PrintWriter(new FileWriter("log.txt", true));
while ((line = br.readLine()) != null) {
if (line.contains("=")) {
if (line.contains("text1")) {
String[] splits = line.split("=");
if (splits.length >= 2) {
out.println(splits[1]);
}
}
if (line.contains("text2")) {
String[] splits = line.split("=");
if (splits.length >= 2) {
out.println(splits[1]);
}
}
}
}
out.flush();
out.close();

Make sure the second if condition is satisfied i.e. the line String contains "text2".

Read text file line by line and store in a class?

I need some help with reading line by line from a file then put it into a class.
My idea is like this: I've saved everything in a text file, it's about 500 lines but this can change that's why I wan't the line number reader and then lnr/5 to get how many times I'll need to run the for loop. I wan't it to first take line 1,2,3,4,5 into a object, then 6,7,8,9,10 and so on. So basically I need each 5 lines go in seperatley.
Code:
public static void g_txt() {
LineNumberReader lnr;
String[] text_array = new String[500];
int nu = 0;
try {
lnr = new LineNumberReader(new FileReader(new File("test.txt")));
lnr.skip(Long.MAX_VALUE);
//System.out.println(lnr.getLineNumber());
lnr.close();
BufferedReader br = new BufferedReader(new FileReader("test.txt"));
String line;
while ((line = br.readLine()) != null) {
text_array[nu] = line;
nu++;
}
} catch (IOException e) {
}
}
as you can see, I now has it in an array. Now I need it to make so 1,2,3,4,5 and so on go in to this:
filmer[antalfilmer] = new FilmSvDe(line1);
filmer[antalfilmer].s_filmbolag(line2);
filmer[antalfilmer].s_producent(line3);
filmer[antalfilmer].s_tid(line4);
filmer[antalfilmer].s_betyg(line5);
filmer[antalfilmer].s_titel(line1);
then antalfilmer++.

public static void g_txt() {
String[] text_array = new String[5];
int nu = 0;
try {
BufferedReader br = new BufferedReader(new FileReader("test.txt"));
String line;
while ((line = br.readLine()) != null) {
text_array[nu] = line;
nu++;
if (nu == 5) {
nu = 0;
makeObject(text_array);
}
}
} catch (IOException e) {
}
}
private static void makeObject(String[] text_array) {
// do your object creation here
System.out.println("_________________________________________________");
for (String string : text_array) {
System.out.println(string);
}
System.out.println("_________________________________________________");
}
Try this.

skip inserting first line of csv file

I have a method that takes data from a .csv file and puts it into an array backwards
(first row goes in last array slot) however I would like the first row in the .csv file to not be in the array. How would I accomplish this? Here is my code thus far:
public static String[][] parse(String symbol) throws Exception{
String destination = "C:/"+symbol+"_table.csv";
LineNumberReader lnr = new LineNumberReader(new FileReader(new File(destination)));
lnr.skip(Long.MAX_VALUE);
String[][] stock_array = new String[lnr.getLineNumber()][3];
try{
BufferedReader br = new BufferedReader(new FileReader(destination));
String strLine = "";
StringTokenizer st = null;
int line = lnr.getLineNumber()-1;
while((strLine = br.readLine()) != null){
st = new StringTokenizer(strLine, ",");
while(st.hasMoreTokens()){
stock_array[line][0] = st.nextToken();
st.nextToken();
stock_array[line][1] = st.nextToken();
stock_array[line][2] = st.nextToken();
st.nextToken();
st.nextToken();
st.nextToken();
}
line--;
}
}
catch(Exception e){
System.out.println("Error while reading csv file: " + e);
}
return stock_array;
}

You can skip the first line by just reading it in and doing nothing. Do this just before your while loop:
br.readLine();
To make sure that your array is the right size and lines get stored in the right places, you should also make these changes:
String[][] stock_array = new String[lnr.getLineNumber()-1][3];
...
int line = lnr.getLineNumber()-2;

Your code is not efficient, as far as my knowledge goes. Also, you are using linenumberreader.skip(long.max_value), which is not a correct/confirmed way to find the line count of the file. StringTokenizer is kind of deprecated way of splitting tokens. I would code it, in the following way:
public static List<String[]> parse(String symbol) throws Exception {
String destination = "C:/"+symbol+"_table.csv";
List<String[]> lines = new ArrayList<String[]>();
try{
BufferedReader br = new BufferedReader(new FileReader(destination));
int index = 0;
while((line = br.readLine()) != null){
if(index == 0) {
index++;
continue; //skip first line
}
lines.add(line.split(","));
}
if(lines != null && !lines.isEmpty()) {
Collections.reverse(lines);
}
} catch(IOException ioe){
//IOException Handling
} catch(Exception e){
//Exception Handling
}
return lines;
}

Best way to read data from a file [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Best way to read a text file
In Java I can open a text file like this:
BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
My question is, how do you read from the following file? The first line is a number (830) representing number of words, and the following lines contain the words.
830
cooking
English
weather
.
.
I want to read the words into a string array. But how do I read the data first?

You're on the right track; I would treat the first line as a special case by parsing it as an integer (see Integer#parseInt(String)) then reading the words as individual lines:
BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
String numLinesStr = reader.readLine();
if (numLinesStr == null) throw new Exception("invalid file format");
List<String> lines = new ArrayList<String>();
int numLines = Integer.parseInt(numLinesStr);
for (int i=0; i<numLines; i++) {
lines.add(reader.readLine());
}

Unless you have some special reason, it's not necessary to keep track of how many lines the file contain. Just use something like this:
BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
String line;
while ((line = reader.readLine()) != null) {
// ...
}

If you're working with Java version greater than 1.5, you can also use the Scanner class:
Scanner sc = new Scanner(new File("someTextFile.txt"));
List<String> words = new ArrayList<String>();
int lines = sc.nextInt();
for(int i = 1; i <= lines; i++) {
words.add(sc.nextLine());
}
String[] w = words.toArray(new String[]{});

Try the class java.io.BufferedReader, created on a java.io.FileReader.
This object has the method readLine, which will read the next line from the file:
try
{
java.io.BufferedReader in =
new java.io.BufferedReader(new java.io.FileReader("filename.txt"));
String str;
while((str = in.readLine()) != null)
{
...
}
}
catch(java.io.IOException ex)
{
}

You could use reflection and do this dynamically:
public static void read() {
try {
BufferedReader reader = new BufferedReader(new FileReader(
"filename.txt"));
String line = reader.readLine();
while (line != null) {
if (Integer.class.isAssignableFrom(line.getClass())) {
int number = Integer.parseInt(line);
System.out.println(number);
} else {
String word = line;
System.out.println(word);
}
line = reader.readLine();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}