RosettaCodeData/Task/CSV-data-manipulation/Java/csv-data-manipulation-4.java

126 lines
3.6 KiB
Java

import java.io.*;
import java.util.*;
import org.apache.commons.csv.*;
public class RCsv {
private static final String NL = System.getProperty("line.separator");
private static final String FILENAME_IR = "data/csvtest_in.csv";
private static final String FILENAME_OR = "data/csvtest_sum.csv";
private static final String COL_NAME_SUM = "SUM, \"integers\""; // demonstrate white space, comma & quote handling
public static void main(String[] args) {
Reader iCvs = null;
Writer oCvs = null;
System.out.println(textFileContentsToString(FILENAME_IR));
try {
iCvs = new BufferedReader(new FileReader(FILENAME_IR));
oCvs = new BufferedWriter(new FileWriter(FILENAME_OR));
processCsv(iCvs, oCvs);
}
catch (IOException ex) {
ex.printStackTrace();
}
finally {
try {
if (iCvs != null) { iCvs.close(); }
if (oCvs != null) { oCvs.close(); }
}
catch (IOException ex) {
ex.printStackTrace();
}
}
System.out.println(textFileContentsToString(FILENAME_OR));
return;
}
public static void processCsv(Reader iCvs, Writer oCvs) throws IOException {
CSVPrinter printer = null;
try {
printer = new CSVPrinter(oCvs, CSVFormat.DEFAULT.withRecordSeparator(NL));
List<String> oCvsHeaders;
List<String> oCvsRecord;
CSVParser records = CSVFormat.DEFAULT.withHeader().parse(iCvs);
Map<String, Integer> irHeader = records.getHeaderMap();
oCvsHeaders = new ArrayList<String>(Arrays.asList((irHeader.keySet()).toArray(new String[0])));
oCvsHeaders.add(COL_NAME_SUM);
printer.printRecord(oCvsHeaders);
for (CSVRecord record : records) {
oCvsRecord = record2list(record, oCvsHeaders);
printer.printRecord(oCvsRecord);
}
}
finally {
if (printer != null) {
printer.close();
}
}
return;
}
private static List<String> record2list(CSVRecord record, List<String> oCvsHeaders) {
List<String> cvsRecord;
Map<String, String> rMap = record.toMap();
long recNo = record.getRecordNumber();
rMap = alterRecord(rMap, recNo);
int sum = 0;
sum = summation(rMap);
rMap.put(COL_NAME_SUM, String.valueOf(sum));
cvsRecord = new ArrayList<String>();
for (String key : oCvsHeaders) {
cvsRecord.add(rMap.get(key));
}
return cvsRecord;
}
private static Map<String, String> alterRecord(Map<String, String> rMap, long recNo) {
int rv;
Random rg = new Random(recNo);
rv = rg.nextInt(50);
String[] ks = rMap.keySet().toArray(new String[0]);
int ix = rg.nextInt(ks.length);
long yv = 0;
String ky = ks[ix];
String xv = rMap.get(ky);
if (xv != null && xv.length() > 0) {
yv = Long.valueOf(xv) + rv;
rMap.put(ks[ix], String.valueOf(yv));
}
return rMap;
}
private static int summation(Map<String, String> rMap) {
int sum = 0;
for (String col : rMap.keySet()) {
String nv = rMap.get(col);
sum += nv != null && nv.length() > 0 ? Integer.valueOf(nv) : 0;
}
return sum;
}
private static String textFileContentsToString(String filename) {
StringBuilder lineOut = new StringBuilder();
Scanner fs = null;
try {
fs = new Scanner(new File(filename));
lineOut.append(filename);
lineOut.append(NL);
while (fs.hasNextLine()) {
String line = fs.nextLine();
lineOut.append(line);
lineOut.append(NL);
}
}
catch (FileNotFoundException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
}
finally {
if (fs != null) {
fs.close();
}
}
return lineOut.toString();
}
}