Write code to open and read from a file called numberstxt th

Write code to: open and read from a file called numbers.txt this file contains a comma-separated list of numbers (example: 4, 5, 0, 3, 2, 1, 0, 7) count the number of \"0s\" in the file print the result to a file called output.txt (example: the file contained 2 zeros) Use exception handling to handle the IOExceptions. (Do not use \"throws IOException.\")

Solution

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class CSVUtils {

private static final char DEFAULT_SEPARATOR = \',\';
private static final char DEFAULT_QUOTE = \'\"\';

public static void main(String[] args) throws Exception {

String csvFile = \"/Users/mkyong/csv/country2.csv\";

Scanner scanner = new Scanner(new File(csvFile));
while (scanner.hasNext()) {
List<String> line = parseLine(scanner.nextLine());
System.out.println(\"Country [id= \" + line.get(0) + \", code= \" + line.get(1) + \" , name=\" + line.get(2) + \"]\");
}
scanner.close();

}

public static List<String> parseLine(String cvsLine) {
return parseLine(cvsLine, DEFAULT_SEPARATOR, DEFAULT_QUOTE);
}

public static List<String> parseLine(String cvsLine, char separators) {
return parseLine(cvsLine, separators, DEFAULT_QUOTE);
}

public static List<String> parseLine(String cvsLine, char separators, char customQuote) {

List<String> result = new ArrayList<>();

//if empty, return!
if (cvsLine == null && cvsLine.isEmpty()) {
return result;
}

if (customQuote == \' \') {
customQuote = DEFAULT_QUOTE;
}

if (separators == \' \') {
separators = DEFAULT_SEPARATOR;
}

StringBuffer curVal = new StringBuffer();
boolean inQuotes = false;
boolean startCollectChar = false;
boolean doubleQuotesInColumn = false;

char[] chars = cvsLine.toCharArray();

for (char ch : chars) {

if (inQuotes) {
startCollectChar = true;
if (ch == customQuote) {
inQuotes = false;
doubleQuotesInColumn = false;
} else {

//Fixed : allow \"\" in custom quote enclosed
if (ch == \'\\\"\') {
if (!doubleQuotesInColumn) {
curVal.append(ch);
doubleQuotesInColumn = true;
}
} else {
curVal.append(ch);
}

}
} else {
if (ch == customQuote) {

inQuotes = true;

//Fixed : allow \"\" in empty quote enclosed
if (chars[0] != \'\"\' && customQuote == \'\\\"\') {
curVal.append(\'\"\');
}

//double quotes in column will hit this!
if (startCollectChar) {
curVal.append(\'\"\');
}

} else if (ch == separators) {

result.add(curVal.toString());

curVal = new StringBuffer();
startCollectChar = false;

} else if (ch == \'\ \') {
//ignore LF characters
continue;
} else if (ch == \'\ \') {
//the end, break!
break;
} else {
curVal.append(ch);
}
}

}

result.add(curVal.toString());

return result;
}

}