I am trying to put column values (CSV file) into an array.
The CSV file:
My code:
public void readFile1()
{
try (BufferedReader br = new BufferedReader(new FileReader(csvFile))) {
while ((line = br.readLine()) != null) {
// use comma as separator
String[] passengerDetails = line.split(cvsSplitBy);
bookingDetails pd = new bookingDetails(passengerDetails[0], passengerDetails[1], passengerDetails[2], passengerDetails[3]);
String x = passengerDetails[2];
System.out.println(passengerDetails[2]); // how to put these values inside an array
}
} catch (IOException e) {
e.printStackTrace();
}}
The output of my code:
Related
I have a text file which has a format similar to this:
===Header1====
LINE1
LINE2
LINE3
===Header2====
LINE1
LINE2
LINE3
What I'm trying to do is parse these out individually to a String variable, so when the reader detects "====Header1====", it will also read all lines underneath til it detects "===Header2===", which will be variable Header1 and so on
Im having issues at the moment with reading out the lines till it detects the next header. I was wondering could anyone shed some light on this? Here is what i have so far
try (BufferedReader br = new BufferedReader(new FileReader(FILE))) {
String sCurrentLine;
while ((sCurrentLine = br.readLine()) != null) {
if (sCurrentLine.startsWith("============= Header 1 ===================")) {
System.out.println(sCurrentLine);
}
if (sCurrentLine.startsWith("============= Header 2 ===================")) {
System.out.println(sCurrentLine);
}
if (sCurrentLine.startsWith("============= Header 3 ===================")) {
System.out.println(sCurrentLine);
}
}
} catch (IOException e) {
e.printStackTrace();
}
You can create a readLines() method which will read the lines till the next header and loads the lines to an arraylist, call readLines() from main() as shown in the below code with inline comments:
public static void main(String[] args) {
BufferedReader br = null;
try {
br = new BufferedReader(new FileReader(new File(FILE)));
//read the 2rd part of the file till Header2 line
List<String> lines1 = readLines(br,
"============= Header 2 ===================");
//read the 2rd part of the file till Header3 line
List<String> lines2 = readLines(br,
"============= Header 3 ===================");
//read the 3rd part of the file till end
List<String> lines3 = readLines(br, "");
} catch (IOException e) {
e.printStackTrace();
} finally {
//close BufferedReader
}
}
private static List<String> readLines(BufferedReader br, String nextHeader)
throws IOException {
String sCurrentLine;
List<String> lines = new ArrayList<>();
while ((sCurrentLine = br.readLine()) != null) {
if("".equals(nextHeader) ||
(nextHeader != null &&
nextHeader.equals(sCurrentLine))) {
lines.add(sCurrentLine);
}
}
return lines;
}
I want to fill an array with names. The array should be filled depending on what gender the character is.
public void fillNameArray() throws IOException {
Character character = new Character(); //Declare and initialise character object
if(character.getGender() == "F"){
List<String> lines = new ArrayList<String>();
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader("femaleNames.txt"));
String line = null;
while ((line = reader.readLine()) != null) {
lines.add(line);
}
} finally {
reader.close();
}
String[] array = (String[]) lines.toArray();
}
else{
List<String> lines = new ArrayList<String>();
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader("maleNames.txt"));
String line = null;
while ((line = reader.readLine()) != null) {
lines.add(line);
}
} finally {
reader.close();
}
String[] array = (String[]) lines.toArray();
}
}
The problem is in the following line:
String[] array = (String[]) lines.toArray();
Write instead:
String[] array = lines.toArray(new String[lines.size()]);
See post as example.
Please can you also move the read code on a own method? So less code duplication.
public List<String> readNames(String file) {
List<String> lines = new ArrayList<String>();
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
String line = null;
while ((line = reader.readLine()) != null) {
lines.add(line);
}
} finally {
reader.close();
}
return lines;
}
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.
I have a text file with more than 20,000 lines and i need to extract specific line from it. The output of this program is completely blank file.
There are 20,000 lines in the txt file and this ISDN line keeps on repeating lots of time each with different value. My text file contains following data.
RecordType=0(MOC)
sequenceNumber=456456456
callingIMSI=73454353911
callingIMEI=85346344
callingNumber
AddInd=H45345'1
NumPlan=H34634'2
ISDN=94634564366 // Need to extract this "ISDN" line only
public String readTextFile(String fileName) {
String returnValue = "";
FileReader file = null;
String line = "";
String line2 = "";
try {
file = new FileReader(fileName);
BufferedReader reader = new BufferedReader(file);
while ((line = reader.readLine()) != null) {
// extract logic starts here
if (line.startsWith("ISDN") == true) {
System.out.println("hello");
returnValue += line + "\n";
}
}
} catch (FileNotFoundException e) {
throw new RuntimeException("File not found");
} finally {
if (file != null) {
try {
file.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return returnValue;
}
We will assume that you use Java 7, since this is 2014.
Here is a method which will return a List<String> where each element is an ISDN:
private static final Pattern ISDN = Pattern.compile("ISDN=(.*)");
// ...
public List<String> getISDNsFromFile(final String fileName)
throws IOException
{
final Path path = Paths.get(fileName);
final List<String> ret = new ArrayList<>();
Matcher m;
String line;
try (
final BufferedReader reader
= Files.newBufferedReader(path, StandardCharsets.UTF_8);
) {
while ((line = reader.readLine()) != null) {
m = ISDN.matcher(line);
if (m.matches())
ret.add(m.group(1));
}
}
return ret;
}
I want to read the 2nd line of text from a file and have that put into an array. I already have it working on the first line.
[ Code removed as requested ]
The while loop above shows how I read and save the 1st line of the text file into an array. I wish to repeat this process from the 2nd line only into a different array.
File Content:
Sofa,Armchair,Computer Desk,Coffee Table,TV Stand,Cushion,Bed,Mattress,Duvet,Pillow
599.99,229.99,129.99,40.00,37.00,08.00,145.00,299.99,24.99,09.99
Just get rid of the first readLine() call, and move the String.split() call into the loop.
Simply use the BufferedReader class to read the entire file and then manipulate the String output.
Something along these lines
public static String readFile(String fileName) throws IOException {
String toReturn = "";
BufferedReader br = null;
try {
String sCurrentLine;
br = new BufferedReader(new FileReader("test.txt"));
while ((sCurrentLine = br.readLine()) != null) {
toReturn = toReturn+"\n"+sCurrentLine;
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
return toReturn;
}
would yield a String which can then be easily used.
public static void main(String[] args)
{
String filePath = args[0];
String[] lineElements = getLine(filePath,2).split(",");
}
public static String getLine(String path,int line)
{
List<String> cases = new ArrayList<String>();
try{
BufferedReader br = new BufferedReader(new FileReader(path));
String currLine = "";
while((currLine = br.readLine()) != null){
cases.add(currLine);
}
}catch(IOException ex){
ex.printStackTrace();
}
return cases.get(line - 1);//2nd line
}