Related
I'm trying to import a txt file with car info and separate the strings into arrays and then display them. The number of doors is combined with the next number plate. Have tried a few ways to get rid of the whitespace characters which I think is causing the issue but have had no luck.
whitespace chars
My code displays this result:
Number Plate : AG53DBO
Car Type : Mercedes
Engine Size : 1000
Colour : (255:0:0)
No. of Doors : 4
MD17WBW
Number Plate : 4
MD17WBW
Car Type : Volkswagen
Engine Size : 2300
Colour : (0:0:255)
No. of Doors : 5
ED03HSH
Code:
public class Application {
public static void main(String[] args) throws IOException {
///// ---- Import File ---- /////
String fileName =
"C:\\Users\\beng\\eclipse-workspace\\Assignment Trailblazer\\Car Data";
BufferedReader reader = new BufferedReader(new FileReader(fileName));
StringBuilder stringBuilder = new StringBuilder();
String line = null;
String ls = System.getProperty("line.separator");
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
stringBuilder.append(ls);
}
reader.close();
String content = stringBuilder.toString();
///// ---- Split file into array ---- /////
String[] dataList = content.split(",");
// Display array
for (String temp : dataList) {
// System.out.println(temp);
}
ArrayList<Car> carArray = new ArrayList();
// Loop variables
int listLength = 1;
int arrayPosition = 0;
// (dataList.length/5)
while (listLength < 5) {
Car y = new Car(dataList, arrayPosition);
carArray.add(y);
listLength++;
arrayPosition += 4;
}
for (Car temp : carArray) {
System.out.println(temp.displayCar());
}
}
}
And
public class Car {
String[] data;
private String modelUnpro;
private String engineSizeUnpro;
private String registrationUnpro;
private String colourUnpro;
private String doorNoUnpro;
// Constructor
public Car(String[] data, int arrayPosition) {
registrationUnpro = data[arrayPosition];
modelUnpro = data[arrayPosition + 1];
engineSizeUnpro = data[arrayPosition + 2];
colourUnpro = data[arrayPosition + 3];
doorNoUnpro = data[arrayPosition + 4];
}
// Getters
private String getModelUnpro() {
return modelUnpro;
}
private String getEngineSizeUnpro() {
return engineSizeUnpro;
}
private String getRegistrationUnpro() {
return registrationUnpro;
}
private String getColourUnpro() {
return colourUnpro;
}
private String getDoorNoUnpro() {
return doorNoUnpro;
}
public String displayCar() {
return "Number Plate : " + getRegistrationUnpro() + "\n Car Type : " + getModelUnpro() + "\n Engine Size : "
+ getEngineSizeUnpro() + "\n Colour : " + getColourUnpro() + "\n No. of Doors : " + getDoorNoUnpro() + "\n";
}
}
Text file:
AG53DBO,Mercedes,1000,(255:0:0),4
MD17WBW,Volkswagen,2300,(0:0:255),5
ED03HSH,Toyota,2000,(0:0:255),4
OH01AYO,Honda,1300,(0:255:0),3
WE07CND,Nissan,2000,(0:255:0),3
NF02FMC,Mercedes,1200,(0:0:255),5
PM16DNO,Volkswagen,1300,(255:0:0),5
MA53OKB,Honda,1400,(0:0:0),4
VV64BHH,Honda,1600,(0:0:255),5
ER53EVW,Ford,2000,(0:0:255),3
Remove Line separator from while loop.
String fileName = "D:\\Files\\a.txt";
BufferedReader reader = new BufferedReader(new FileReader(fileName));
StringBuilder stringBuilder = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line.trim());
}
reader.close();
String content = stringBuilder.toString();
String[] dataList = content.split(",");
ArrayList<Car> carArray = new ArrayList();
int listLength = 1;
int arrayPosition = 0;
// (dataList.length/5)
while (listLength < 3) {
Car y = new Car(dataList, arrayPosition);
carArray.add(y);
listLength++;
arrayPosition += 4;
}
for (Car temp : carArray) {
System.out.println(temp.displayCar());
}
In StringBuilder you collect all lines:
AG53DBO,Mercedes,1000,(255:0:0),4\r\nMD17WBW,Volkswagen,2300,(0:0:255),5\r\n...
This string should first be spit on ls - and then you have lines with fields separated by comma.
Now just splitting by comma will cause a doubled array element 4\r\nMD17WBW.
Something like:
String fileName =
"C:\\Users\\beng\\eclipse-workspace\\Assignment Trailblazer\\Car Data";
Path path = Paths.get(fileName);
List<String> lines = Files.readAllLines(path); // Without line ending.
List<Car> cars = new ArrayList<>();
for (String line : lines) {
String[] data = line.split(",");
Car car = new Car(data);
cars.add(car);
}
Path, Paths and especially Files are very handy classes. With java Streams one also can abbreviate things like:
String fileName =
"C:\\Users\\beng\\eclipse-workspace\\Assignment Trailblazer\\Car Data";
Path path = Paths.get(fileName);
List<Car> cars = Files.lines(path) // Stream<String>
.map(line -> line.split(",")) // Stream<String[]>
.map(Car::new) // Stream<Car>
.collect(Collectors.toList()); // List<Car>
Here .lines returns a Stream<String> (walking cursor) of lines in the file, without line separator.
Then .map(l -> l.split(",")) splits every line.
Then the Car(String[]) constructor is called on the string array.
Then the result is collected in a List.
I am trying to write 2 different arrays to a csv. The first one I want in the first column, and second array in the second column, like so:
array1val1 array2val1
array1val2 array2val2
I am using the following code:
String userHomeFolder2 = System.getProperty("user.home") + "/Desktop";
String csvFile = (userHomeFolder2 + "/" + fileName.getText() + ".csv");
FileWriter writer = new FileWriter(csvFile);
final String NEW_LINE_SEPARATOR = "\n";
FileWriter fileWriter;
CSVPrinter csvFilePrinter;
CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR);
fileWriter = new FileWriter(fileName.getText());
csvFilePrinter = new CSVPrinter(fileWriter, csvFileFormat);
try (PrintWriter pw = new PrintWriter(csvFile)) {
pw.printf("%s\n", FILE_HEADER);
for(int z = 0; z < compSource.size(); z+=1) {
//below forces the result to get stored in below variable as a String type
String newStr=compSource.get(z);
String newStr2 = compSource2.get(z);
newStr.replaceAll(" ", "");
newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
pw.printf("%s\n", explode, explode2);
}
}
catch (Exception e) {
System.out.println("Error in csvFileWriter");
e.printStackTrace();
} finally {
try {
fileWriter.flush();
fileWriter.close();
csvFilePrinter.close();
} catch (IOException e ) {
System.out.println("Error while flushing/closing");
}
}
However I am getting a strange output into the csv file:
[Ljava.lang.String;#17183ab4
I can run
pw.printf("%s\n", explode);
pw.printf("%s\n", explode2);
Instead of : pw.printf("%s\n", explode, explode2);
and it prints the actual strings but all in one same column.
Does anyone know how to solve this?
1.Your explode and explode2 are actually String Arrays. You are printing the arrays and not the values of it. So you get at the end the ADRESS of the array printed.
You should go through the arrays with a loop and print them out.
for(int i = 0; i<explode.length;++i) {
pw.printf("%s%s\n", explode[i], explode2[i]);
}
2.Also the method printf should be look something like
pw.printf("%s%s\n", explode, explode2);
because youre are printing two arguments, but in ("%s\n", explode, explode2) is only one printed.
Try it out and say if it worked
After these lines:
newStr.replaceAll(" ", "");
newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
Use this code:
int maxLength = Math.max(explode.length, explode2.length);
for (int i = 0; i < maxLength; i++) {
String token1 = (i < explode.length) ? explode[i] : "";
String token2 = (i < explode2.length) ? explode2[i] : "";
pw.printf("%s %s\n", token1, token2);
}
This also cover the case that the arrays are of different length.
I have removed all unused variables and made some assumptions about content of compSource.
Moreover, don't forget String is immutable. If you just do "newStr.replaceAll(" ", "");", the replacement will be lost.
public class Tester {
#Test
public void test() throws IOException {
// I assumed compSource and compSource2 are like bellow
List<String> compSource = Arrays.asList("array1val1,array1val2");
List<String> compSource2 = Arrays.asList("array2val1,array2val2");
String userHomeFolder2 = System.getProperty("user.home") + "/Desktop";
String csvFile = (userHomeFolder2 + "/test.csv");
try (PrintWriter pw = new PrintWriter(csvFile)) {
pw.printf("%s\n", "val1,val2");
for (int z = 0; z < compSource.size(); z++) {
String newStr = compSource.get(z);
String newStr2 = compSource2.get(z);
// String is immutable --> store the result otherwise it will be lost
newStr = newStr.replaceAll(" ", "");
newStr2 = newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
for (int k = 0; k < explode.length; k++) {
pw.println(explode[k] + "\t" + explode2[k]);
}
}
}
}
}
In the method, i have all these initialize
Scanner input = new Scanner(System.in);
File file = new File("order.dat");
File viewOrder = new File("ViewOrder.dat");
String orderNo, itemNo, itemNameHolder, qtyHolder, priceHolder, status;
int hold, count = 0, countArray = 0;
double tempPriceHolder, totalPrice = 0;
String tempStatus = "";
String[] holdItemNo = null;
String[] holdName = null;
Integer[] holdQty = null;
Double[] holdTotal = null;
String[] holdStatus = null;
After, i try to read all my content in the file and store the content into holdX array
try {
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String line = null;
while ((line = br.readLine()) != null) {
String tokens[] = line.split(";");
orderNo = tokens[0];
itemNo = tokens[1];
itemNameHolder = tokens[2];
qtyHolder = tokens[3];
priceHolder = tokens[4];
status = tokens[5];
if (orderNo.equalsIgnoreCase(userOrderNo)) {
tempPriceHolder = Double.parseDouble(priceHolder);
hold = Integer.parseInt(qtyHolder);
tempPriceHolder = tempPriceHolder * hold;
totalPrice += tempPriceHolder;
countArray++;
holdItemNo = new String[countArray];
holdName = new String[countArray];
holdQty = new Integer[countArray];
holdTotal = new Double[countArray];
holdStatus = new String[countArray];
if (status.matches("s")) {
tempStatus = "Success";
} else if (status.matches("p")) {
tempStatus = "Partially Full";
} else if (status.matches("o")) {
tempStatus = "Out of Stock";
}
holdItemNo[count] = itemNo;
holdName[count] = itemNameHolder;
holdQty[count] = hold;
holdTotal[count] = tempPriceHolder;
holdStatus[count] = tempStatus;
count++;
}
}
} catch (Exception e) {
System.out.println("Error");
}
Final, i write all my array into a new file.
System.out.printf("%s %15s %15s %10s %10s\n", "Item No", "Description", "Quantity", "Total", "Status");
for (int i = 0; i < holdItemNo.length; i++) {
System.out.printf("\n%-11s %-18s %-13s $%-8s %s \n", holdItemNo[i], holdName[i], holdQty[i], holdTotal[i], holdStatus[i]);
}
System.out.println("-----------------------------------------------------------------------");
System.out.printf("%46s %s\n", "$", totalPrice);
System.out.print("Print Order to file Y/N: ");
String choice = input.next();
if (choice.equalsIgnoreCase("y")) {
try {
PrintWriter bw = new PrintWriter(new FileWriter("ViewOrder.dat", true));
for (int i = 0; i < holdItemNo.length; i++) {
bw.write(userOrderNo + ";" + holdItemNo[i] + ";" + holdName[i] + ";" + holdQty[i] + ";" + holdTotal[i] + ";" + holdStatus[i] + "\n");
bw.flush();
}
bw.flush();
bw.close();
System.out.println("Sucessfull!");
} catch (Exception e) {
System.out.println("Error");
}
} else if (choice.equalsIgnoreCase("n")) {
System.out.println("");
}
but the problem is even my code is working but the output is not what i expected. It printed out the printed out the last content and also the sub price is working as well but the rest is only printed out NULL.
Example
Also, it gave me warning of Derefencing possible null pointer on the array.length
for (int i = 0; i < holdItemNo.length; i++) {
bw.write(userOrderNo + ";" + holdItemNo[i] + ";" + holdName[i] + ";" + holdQty[i] + ";" + holdTotal[i] + ";" + holdStatus[i] + "\n");
bw.flush();
}
Guessing:
holdItemNo = new String[countArray];
and the following lines: you are creating these new array objects within your reading loop (inside a condition).
So probably that condition never goes true; therefore your arrays stay all null. But even when the condition is met - you probably expect that to happen more then once. And guess what: you are creating completely new arrays then. While throwing away the previously created array. Each time the if condition turns true you will lose previously stored values!
So the answer is: create your arrays before entering the loop. This means that you either have to query "how many slots to create" upfront; or you have to create an array with say 100 empty slots; and within your loop you then have to check if you still have free slots.
Or you start using java.util.List resp. ArrayList - which allows for dynamic adding of elements.
I am facing a problem in the following code. I am trying to run the program and it terminates when it hits empty space in my input. How else I should approach this.
try {
BufferedReader sc = new BufferedReader(new FileReader(text.txt);
ArrayList<String> name = new ArrayList<>();
ArrayList<String> id = new ArrayList<>();
ArrayList<String> place = new ArrayList<>();
ArrayList<String> details = new ArrayList<>();
String line = null;
while ((line = sc.readLine()) !=null) {
if (!line.trim().equals("")) {
System.out.println(line);
if (line.toLowerCase().contains("name")) {
name.add(line.split("=")[1].trim());
}
if (line.toLowerCase().contains("id")) {
id.add(line.split("=")[1].trim());
}
if (line.toLowerCase().contains("location")) {
place.add(line.split("=")[1].trim());
}
if (line.toLowerCase().contains("details")) {
details.add(line.split("=")[1].trim());
}
}
}
PrintWriter pr = new PrintWriter(new File(text.csv));
pr.println("Name;Id;;Location;Details");
for (int i = 0; i < name.size(); i++) {
pr.println(name.get(i) + ";" + id.get(i) + ";" + place.get(i) + ";" + details.get(i));
}
pr.close();
sc.close();
} catch (Exception e) {
e.printStackTrace();
} }
My Input looks like
name = abc
id = 123
place = xyz
details = hsdyhuslkjaldhaadj
name = ert
id = 7872
place =
details = shahkjdhksdhsala
name = sfd
id = 4343
place = ksjks
Details = kljhaljs
when im trying to execute then above text my program terminates at place = "null" because of no value there.I need the output as an empty space created in place ="null" and print the rest as follows in a .csv file
If you process the location, line.split("=")[1] could result in an ArrayIndexOutOfBoundException and line.split("=")[1].trim() could result in a NullPointerException.
You can avoid this by testing your parsed result.
Instead of place.add(line.split("=")[1].trim());, do place.add(parseContentDefaultEmpty(line));, with:
private String parseContentDefaultEmpty(final String line) {
final String[] result = line.split("=");
if(result.length <= 1) {
return "";
}
final String content = line.split("=")[1];
return content != null ? content.trim() : "";
}
First there is a issue,your input file contains key as "place" but your are trying for word "location"
if (line.toLowerCase().contains("location")) { //this must be changed to place
place.add(line.split("=")[1].trim());
}
Modified the code snippet as below.check it
while ((line = sc.readLine()) != null) {
if (!line.trim().equals("")) {
System.out.println(line);
if (line.toLowerCase().contains("name")) {
name.add(line.split("=")[1].trim());
}
if (line.toLowerCase().contains("id")) {
id.add(line.split("=")[1].trim());
}
if (line.toLowerCase().contains("place")) {
// change done here to add space if no value
place.add(line.split("=").length > 1 ? line.split("=")[1]
.trim() : " ");
}
if (line.toLowerCase().contains("details")) {
details.add(line.split("=")[1].trim());
}
}
}
Setting question to line doesn't appear to change what line is read later (if you're wanting the line to advance before it hits the while loop).
I want to read specific columns from a multi column csv file and print those columns in other csv file using Java. Any help please? Following is my code to print each token line by line..But I am looking to print only few columns out of the multi column csv.
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.StringTokenizer;
public class ParseCSV {
public static void main(String[] args) {
try
{
//csv file containing data
String strFile = "C:\\Users\\rsaluja\\CMS_Evaluation\\Drupal_12_08_27.csv";
//create BufferedReader to read csv file
BufferedReader br = new BufferedReader( new FileReader(strFile));
String strLine = "";
StringTokenizer st = null;
int lineNumber = 0, tokenNumber = 0;
//read comma separated file line by line
while( (strLine = br.readLine()) != null)
{
lineNumber++;
//break comma separated line using ","
st = new StringTokenizer(strLine, ",");
while(st.hasMoreTokens())
{
//display csv values
tokenNumber++;
System.out.println("Line # " + lineNumber +
", Token # " + tokenNumber
+ ", Token : "+ st.nextToken());
System.out.println(cols[4]);
You should use the excellent OpenCSV for reading and writing CSV files. To adapt your example to use the library it would look like this:
public class ParseCSV {
public static void main(String[] args) {
try {
//csv file containing data
String strFile = "C:/Users/rsaluja/CMS_Evaluation/Drupal_12_08_27.csv";
CSVReader reader = new CSVReader(new FileReader(strFile));
String [] nextLine;
int lineNumber = 0;
while ((nextLine = reader.readNext()) != null) {
lineNumber++;
System.out.println("Line # " + lineNumber);
// nextLine[] is an array of values from the line
System.out.println(nextLine[4] + "etc...");
}
}
}
}
Reading a CSV file in very simple and common in Java. You actually don't require to load any extra third party library to do this for you. CSV (comma separated value) file is just a normal plain-text file, store data in column by column, and split it by a separator (e.g comma ",").
In order to read specific columns from the CSV file, there are several ways. Simplest of all is as below:
Code to read CSV without any 3rd party library
BufferedReader br = new BufferedReader(new FileReader(csvFile));
while ((line = br.readLine()) != null) {
// use comma as separator
String[] cols = line.split(cvsSplitBy);
System.out.println("Coulmn 4= " + cols[4] + " , Column 5=" + cols[5]);
}
If you notice, nothing special is performed here. It is just reading a text file, and spitting it by a separator – ",".
Consider an extract from legacy country CSV data at GeoLite Free Downloadable Databases
"1.0.0.0","1.0.0.255","16777216","16777471","AU","Australia"
"1.0.1.0","1.0.3.255","16777472","16778239","CN","China"
"1.0.4.0","1.0.7.255","16778240","16779263","AU","Australia"
"1.0.8.0","1.0.15.255","16779264","16781311","CN","China"
"1.0.16.0","1.0.31.255","16781312","16785407","JP","Japan"
"1.0.32.0","1.0.63.255","16785408","16793599","CN","China"
"1.0.64.0","1.0.127.255","16793600","16809983","JP","Japan"
"1.0.128.0","1.0.255.255","16809984","16842751","TH","Thailand"
Above code will output as below:
Column 4= "AU" , Column 5="Australia"
Column 4= "CN" , Column 5="China"
Column 4= "AU" , Column 5="Australia"
Column 4= "CN" , Column 5="China"
Column 4= "JP" , Column 5="Japan"
Column 4= "CN" , Column 5="China"
Column 4= "JP" , Column 5="Japan"
Column 4= "TH" , Column 5="Thailand"
You can, in fact, put the columns in a Map and then get the values simply by using the key.
Shishir
I am sorry, but none of these answers provide an optimal solution. If you use a library such as OpenCSV you will have to write a lot of code to handle special cases to extract information from specific columns.
For example, if you have rows with less columns than what you're after, you'll have to write a lot of code to handle it. Using the OpenCSV example:
CSVReader reader = new CSVReader(new FileReader(strFile));
String [] nextLine;
while ((nextLine = reader.readNext()) != null) {
//let's say you are interested in getting columns 20, 30, and 40
String[] outputRow = new String[3];
if(parsedRow.length < 40){
outputRow[2] = null;
} else {
outputRow[2] = parsedRow[40]
}
if(parsedRow.length < 30){
outputRow[1] = null;
} else {
outputRow[1] = parsedRow[30]
}
if(parsedRow.length < 20){
outputRow[0] = null;
} else {
outputRow[0] = parsedRow[20]
}
}
This is a lot of code for a simple requirement. It gets worse if you are trying to get values of columns by name. You should use a more modern parser such as the one provided by uniVocity-parsers.
To reliably and easily get the columns you want, simply write:
CsvParserSettings settings = new CsvParserSettings();
parserSettings.selectIndexes(20, 30, 40);
CsvParser parser = new CsvParser(settings);
List<String[]> allRows = parser.parseAll(new FileReader(yourFile));
Disclosure: I am the author of this library. It's open-source and free (Apache V2.0 license).
To read some specific column
I did something like this:
dpkcs.csv content:
FN,LN,EMAIL,CC
Name1,Lname1,email1#gmail.com,CC1
Nmae2,Lname2,email2r#gmail.com,CC2
The function to read it:
private void getEMailRecepientList() {
List<EmailRecepientData> emailList = null;// Blank list of POJO class
Scanner scanner = null;
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader("dpkcs.csv"));
Map<String, Integer> mailHeader = new HashMap<String, Integer>();
// read file line by line
String line = null;
int index = 0;
line = reader.readLine();
// Get header from 1st row of csv
if (line != null) {
StringTokenizer str = new StringTokenizer(line, ",");
int headerCount = str.countTokens();
for (int i = 0; i < headerCount; i++) {
String headerKey = str.nextToken();
mailHeader.put(headerKey.toUpperCase(), new Integer(i));
}
}
emailList = new ArrayList<EmailRecepientData>();
while ((line = reader.readLine()) != null) {
// POJO class for getter and setters
EmailRecepientData email = new EmailRecepientData();
scanner = new Scanner(line);
scanner.useDelimiter(",");
//Use Specific key to get value what u want
while (scanner.hasNext()) {
String data = scanner.next();
if (index == mailHeader.get("EMAIL"))
email.setEmailId(data);
else if (index == mailHeader.get("FN"))
email.setFirstName(data);
else if (index == mailHeader.get("LN"))
email.setLastName(data);
else if (index == mailHeader.get("CC"))
email.setCouponCode(data);
index++;
}
index = 0;
emailList.add(email);
}
reader.close();
} catch (Exception e) {
StringWriter stack = new StringWriter();
e.printStackTrace(new PrintWriter(stack));
} finally {
scanner.close();
}
System.out.println("list--" + emailList);
}
The POJO Class:
public class EmailRecepientData {
private String emailId;
private String firstName;
private String lastName;
private String couponCode;
public String getEmailId() {
return emailId;
}
public void setEmailId(String emailId) {
this.emailId = emailId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getCouponCode() {
return couponCode;
}
public void setCouponCode(String couponCode) {
this.couponCode = couponCode;
}
#Override
public String toString() {
return "Email Id=" + emailId + ", First Name=" + firstName + " ,"
+ " Last Name=" + lastName + ", Coupon Code=" + couponCode + "";
}
}
I sugges to use the Apache Commons CSV https://commons.apache.org/proper/commons-csv/
Here is one example:
Path currentRelativePath = Paths.get("");
String currentPath = currentRelativePath.toAbsolutePath().toString();
String csvFile = currentPath + "/pathInYourProject/test.csv";
Reader in;
Iterable<CSVRecord> records = null;
try
{
in = new FileReader(csvFile);
records = CSVFormat.EXCEL.withHeader().parse(in); // header will be ignored
}
catch (IOException e)
{
e.printStackTrace();
}
for (CSVRecord record : records) {
String line = "";
for ( int i=0; i < record.size(); i++)
{
if ( line == "" )
line = line.concat(record.get(i));
else
line = line.concat("," + record.get(i));
}
System.out.println("read line: " + line);
}
It automaticly recognize , and " but not ; (maybe it can be configured...).
My example file is:
col1,col2,col3
val1,"val2",val3
"val4",val5
val6;val7;"val8"
And output is:
read line: val1,val2,val3
read line: val4,val5
read line: val6;val7;"val8"
Last line is considered like one value.
We can use the core java stuff alone to read the CVS file column by column. Here is the sample code I have wrote for my requirement. I believe that it will help for some one.
BufferedReader br = new BufferedReader(new FileReader(csvFile));
String line = EMPTY;
int lineNumber = 0;
int productURIIndex = -1;
int marketURIIndex = -1;
int ingredientURIIndex = -1;
int companyURIIndex = -1;
// read comma separated file line by line
while ((line = br.readLine()) != null) {
lineNumber++;
// use comma as line separator
String[] splitStr = line.split(COMMA);
int splittedStringLen = splitStr.length;
// get the product title and uri column index by reading csv header
// line
if (lineNumber == 1) {
for (int i = 0; i < splittedStringLen; i++) {
if (splitStr[i].equals(PRODUCTURI_TITLE)) {
productURIIndex = i;
System.out.println("product_uri index:" + productURIIndex);
}
if (splitStr[i].equals(MARKETURI_TITLE)) {
marketURIIndex = i;
System.out.println("marketURIIndex:" + marketURIIndex);
}
if (splitStr[i].equals(COMPANYURI_TITLE)) {
companyURIIndex = i;
System.out.println("companyURIIndex:" + companyURIIndex);
}
if (splitStr[i].equals(INGREDIENTURI_TITLE)) {
ingredientURIIndex = i;
System.out.println("ingredientURIIndex:" + ingredientURIIndex);
}
}
} else {
if (splitStr != null) {
String conditionString = EMPTY;
// avoiding arrayindexoutboundexception when the line
// contains only ,,,,,,,,,,,,,
for (String s : splitStr) {
conditionString = s;
}
if (!conditionString.equals(EMPTY)) {
if (productURIIndex != -1) {
productCVSUriList.add(splitStr[productURIIndex]);
}
if (companyURIIndex != -1) {
companyCVSUriList.add(splitStr[companyURIIndex]);
}
if (marketURIIndex != -1) {
marketCVSUriList.add(splitStr[marketURIIndex]);
}
if (ingredientURIIndex != -1) {
ingredientCVSUriList.add(splitStr[ingredientURIIndex]);
}
}
}
}
Finds all files in folder and write that data to ArrayList row.
Initialize
ArrayList<ArrayList<String>> row=new ArrayList<ArrayList<String>>();
BufferedReader br=null;
For Accessing row
for(ArrayList<String> data:row){
data.get(col no);
}
or row.get(0).get(0) // getting first row first col
Functions that reads all files from folders and concatenate them row.
static void readData(){
String path="C:\\Users\\Galaxy Computers\\Desktop\\Java project\\Nasdaq\\";
File files=new File(path);
String[] list=files.list();
try {
String sCurrentLine;
char check;
for(String filename:list){
br = new BufferedReader(new FileReader(path+filename));
br.readLine();//If file contains uneccessary first line.
while ((sCurrentLine = br.readLine()) != null) {
row.add(splitLine(sCurrentLine));
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
static ArrayList<String> splitLine(String line){
String[] ar=line.split(",");
ArrayList<String> d=new ArrayList<String>();
for(String data:ar){
d.add(data);
}
return d;
}
Well, how about this !!
This code calculates both row and column count in a csv file. Try this out !!
static int[] getRowsColsNo() {
Scanner scanIn = null;
int rows = 0;
int cols = 0;
String InputLine = "";
try {
scanIn = new Scanner(new BufferedReader(
new FileReader("filename.csv")));
scanIn.useDelimiter(",");
while (scanIn.hasNextLine()) {
InputLine = scanIn.nextLine();
String[] InArray = InputLine.split(",");
rows++;
cols = InArray.length;
}
} catch (Exception e) {
System.out.println(e);
}
return new int[] { rows, cols };
}