package com.mkyong.util;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class ReadFromCVS {
ArrayList<datas> dataList = new ArrayList<datas>();
public static void main(String[] args) {
ReadFromCVS obj = new ReadFromCVS();
obj.run();
obj.printDataList(obj.dataList);
}
public void run() {
String csvFile = "C:\\Users\\User\\Downloads\\SalesData.csv";
BufferedReader br = null;
String csvSplitBy = ",";
String line = "";
try {
br = new BufferedReader(new FileReader(csvFile));
br.readLine();
while ((line = br.readLine()) != null) {
// split on comma
String[] datas = line.split(csvSplitBy);
// crate data object to store values
datas dataObject = new datas();
// add values from the csv file to data object
dataObject.setProductId(Integer.parseInt(datas[0]));
dataObject.setUnits(Integer.parseInt(datas[1]));
// adding data object to a list
dataList.add(dataObject);
}
// print values stored in a datalist
Collections.sort(dataList);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public void printDataList(List<datas> dataListToPrint) {
for (int i = 0; i < dataListToPrint.size(); i++) {
System.out.println("Product ID: " + dataListToPrint.get(i).getProductId() + " Units: "
+ dataListToPrint.get(i).getUnits());
}
}
}
class datas implements Comparable<datas> {
private int productId;
private int units;
public int getProductId() {
return productId;
}
public void setProductId(int productId) {
this.productId = productId;
}
public int getUnits() {
return units;
}
public void setUnits(int units) {
this.units = units;
}
@Override
public int compareTo(datas d) {
if (this.getProductId() > d.getProductId()) {
return 1;
} else if (this.getProductId() < d.getProductId()) {
return -1;
} else {
return 0;
}
}
}
what ia trying to do is read csv file( contains (product Id and units) and put them in arraylist of objects, then sort the arraylist in ascending order, then I have to look for duplicate product id and add the units to same single product id so their will be no duplicate in the second arraylist.. i am having trouble creating second arraylist and moving the unique products and adding the duplicate product id units to the same unique id units.. please help me
This the out put i get so far:
Product ID: 10001 Units: 5
Product ID: 10001 Units: 8
Product ID: 10001 Units: 7
Product ID: 10002 Units: 4
Product ID: 10002 Units: 10
Product ID: 10002 Units: 6
Product ID: 10003 Units: 8
Product ID: 10003 Units: 6
Product ID: 10003 Units: 3
Product ID: 10003 Units: 7
Product ID: 10003 Units: 4
Product ID: 10004 Units: 6
Product ID: 10004 Units: 9
