Getting key and value of linkedHashMap

Question

I try to read data from csv file, save it to linkedHashMap and print it. But the thing is that I neet print key and value separately. Csv file has just 2 columns: First: email, Second: name.

public class CsvReader {

String CSVPath = "c:/Users/PC/Desktop/file.csv";
CSVReader reader;

public void readCsvFile() throws IOException {
    try {

        reader = new CSVReader(new FileReader(CSVPath));
        String[] column;
        ArrayList<LinkedHashMap<String, String>> myArraylist = new 
    ArrayList<LinkedHashMap<String, String>>();
        LinkedHashMap<String, String> map;

        while ((column = reader.readNext()) != null) {
            map = new LinkedHashMap<String, String>();
            map.put("Emails", column[0]);
            myArraylist.add(map);
        }
        reader.close();

        for (int i = 0; i < myArraylist.size(); i++) {

System.out.println(myArraylist.get(i).get("Emails").toString());

        }

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}


}

When I run this code I get the following:

info@staybysantacruz.com;Quality Inn & Suites Santa Cruz Mountains
VacationRentals321@gmail.com;In Big Bear
info@haiyi-hotels.com;Best Western Americania

so it prints email and the name together. I tried to get to key and value of the linkedHashMap but with no luck. Could someone help me?

CSV file is here: https://ufile.io/43d2t. It doesn't have any semicolons. — Alex20280, Oct 31 '18 at 23:43
Basically I need to save date to LinkedHAshMap and later on to be able to print out either Key or Value. But not a Key + Value at the same time. — Alex20280, Oct 31 '18 at 23:55

score 1 · Answer 1 · answered Oct 31 '18 at 07:38

1

As in your CSV file data separated with semi-columns so first of all, you have to provide CsvReader separator.

 reader = new CSVReader(new FileReader(CSVPath),";");

This is deprecated constructor initialization.

For the latest API you can use below code for getting CSVReader to object with the separator.

 final CSVParser parser = new CSVParserBuilder()
  .withSeparator(';')
  .withIgnoreQuotations(true)
  .build();

final CSVReader reader = new CSVReaderBuilder(new StringReader(csv))
  .withSkipLines(1)
  .withCSVParser(parser)
  .build();

Assuming you have separator semi-column if you have any other separator except comma because it's default separator for CSVReader

answered Oct 31 '18 at 07:38

Kumar Panchal

186
13

In fact it doesn't contain ";". You can check csv file here: https://uploadfiles.io/43d2t. I have no idea yet why it prints ";". – Alex20280 Oct 31 '18 at 23:56
in you CSV file info@staybysantacruz.com;Quality Inn & Suites Santa Cruz Mountains. Only ; is dividing both values – Kumar Panchal Nov 01 '18 at 12:31
Now I try to get info directly from Excel or Json file. Let's see if I cano do that. – Alex20280 Nov 06 '18 at 01:54
Ok verify it @Alex20280 – Kumar Panchal Nov 06 '18 at 07:16

score 0 · Answer 2 · answered Oct 31 '18 at 06:00

0

You are reading this as CSV, but it seems to be seperated by a semicolon

so split

String email = column[0].split (";")[0];
String desc = column[0].split (";")[1];

answered Oct 31 '18 at 06:00

Scary Wombat

44,617
6
35
64

Amit Kumar Lal · Answer 3 · 2018-10-31T07:06:30.497

For csv file it's better to use Apache commons csv jar as its effective and meant to read CSV with minimal code and better features below is the code for the same

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;

public class Test {

    static String CSVPath = "c:/Test/SampleFile.csv";

    public static void main(String...strings) throws IOException {
        Map<String, String> userNameEmailMap = new HashMap<String, String>();
        CSVParser csvParser = new CSVParser(new FileReader(new File(CSVPath)), CSVFormat.DEFAULT);
        List<CSVRecord> values = csvParser.getRecords();
        for (CSVRecord csvRecord : values) {
            for (String rowRecord : csvRecord) {
                String[] records = rowRecord.split("\\s+");
                System.out.println(Arrays.toString(records));
                //if you want to add it to a map 
                userNameEmailMap.put(records[0], records[1]);
            }
        }
        csvParser.close();

        for (Entry<String, String> entry : userNameEmailMap.entrySet()) {
            System.out.println("Email :: "+entry.getKey()+"   "+"Value :: "+entry.getValue());
        }
    }
}

I have used commons-csv 1.5 maven link https://mvnrepository.com/artifact/org.apache.commons/commons-csv/1.5

It's better to use commons csv as it helps in future extensibility if the extra column is added.

Getting key and value of linkedHashMap

3 Answers3