Develop Reference

StringTokenizer is not getting right value after delimiter

I'm trying to get the string from ARCHIVE_FILE_EXTENSION_FILTER but somehow it is not taking the first value and returning NULL
Below is the properties info
#indicate any file extensions to filter by - must be comma-delimited. Enter 'none' to get all files
Text.FileArchiver.INV_ARCHIVE_FILE_EXTENSION_FILTER=done , proc
May I know why it's not working the value and any issue with my code
String extension = env.getProperty(trimIni(ARCHIVE_FILE_EXTENSION_FILTER));
if (Objects.nonNull(extension) && !NONE.equalsIgnoreCase(extension)) {
StringTokenizer token = new StringTokenizer(extension, ",");
int i = 0;
String[] tmpExtensions = {};
if (token.countTokens() > 0) {
tmpExtensions = new String[token.countTokens()];
}
while (token.hasMoreTokens()) {
tmpExtensions[i] = token.nextToken();
}
extensions = tmpExtensions;
}

Parsing csv data into object with different column length

I am new to Java and practicing parsing csv file into the object. I've tried but cannot figure it out.
The file looks like this:
[0], [1], [2], [3] , [4] , [5] , [6] , [7] , [8] , [9]
class, gender, age, bodyType, profession, pregnant, isYou ,species, isPet, role
scenario:green, , , , , , , ,
person, female, 24, average , , FALSE , , , , passenger
animal, male , 4, , , FALSE , , dog , TRUE , pedestrian
scenario:red
person, male , 16, athletic, boxer , FALSE , TRUE , , , passenger
person, female, 25, athletic, doctor , TRUE , FALSE , , , pedestrian
I need to parse it by any number of passengers and pedestrians with any scenarios. Finally, add these scenarios into an ArrayList for analyzing.
What I think is to:
loop through each line, stops when reaches to the next scenario:red, adds the passengers and the pedestrians to the Character ArrayList. (I've done adding, but don't how to stop).
Create a scenario using constructor scenario(ArrayList<Character> passenger, ArrayList<Character> pedestrians, boolean redOrGreen);
The ArrayList scenarios add the created scenarios.
What I've done is put everything together instead of separate them. Any help or hint is highly appreciated.
Thanks for this community who helped me, here is what I've got so far.
public void loadCsv() throws IOException {
String csvFile = "config.csv";
String line = "";
String csvSplit = "\\s*,\\s*";
Scenario scenario = new Scenario();
Person person = new Person();
Animal animal = new Animal();
ArrayList<Scenario> scenaios = new ArrayList<Scenario>();
ArrayList<String> csvContents = new ArrayList<String>();
ArrayList<Character> passengers = new ArrayList<Character>();
ArrayList<Character> pedestrians = new ArrayList<Character>();
try (BufferedReader csvReader = new BufferedReader(new FileReader(csvFile));) {
String headerLine = csvReader.readLine(); //get rid of the header
//add each line to the arrayList
while ((line = csvReader.readLine()) != null) {
csvContents.add(line);
}
for(String csvLine : csvContents) {
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
if (data.length == NO_OF_FIELD) { //check and avoid indexOutOfBoundException
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
if (clazz.startsWith("scenario") && data.length == 1) {
scenario = new Scenario();
scenario.setLegalCrossing(clazz.endsWith("green"));
continue;
}
else if ("person".equals(clazz) && data.length ==10) {
person = loadCsvPerson(data);
addCharacter(person, data);
}
else if ("animal".equals(clazz) && data.length ==10) {
animal = loadCsvAnimal(data);
addCharacter(animal, data);
}
}
}
}
//passenger and pedestrians are in position
System.out.println("passengers: " + passengers);
System.out.println("pedestrians: " + pedestrians);
if (null != scenario) {
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}

If it is possible to change the csv file format, I would add scenario type column (and scenario id or name if required), so you can work with csv file as a result set from database when you join tables (scenario + passenger + pedestrian) and return plain rows.
With this approach you will be able to delegate parsing to any csv library and do your logic (group by scenario id/name/type) separately. With surrogate rows you have (scenario:green...) you have to write your custom parser.
For example, you can use univocity to simply parse file into your model (even using annotations) and iteratively group it and handle.

Or if you need to work with existing file format do something like that:
if (clazz.startsWith("scenario") && data.length == 1) {
// collect existing scenario before starting processing new one
if (scenario != null) {
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
passengers = new ArrayList();
pedestrians = new ArrayList();
scenarios.add(scenario);
}
// now start new group (scenario)
scenario = new Scenario();
scenario.setLegalCrossing(clazz.endsWith("green"));
continue;
}

Following things need to be addressed in your code:
Strive to avoid using the name of a class which is already used by the standard library (and especially when it is in the default package, java.lang) e.g. there is already a class Character in Java library and therefore you should use a different name for your custom class.
Use continue to skip the line, scenario:red
for(String csvLine : csvContents) {
if(csvLine.equals("scenario:red")){
continue;
}
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
if (data.length == NO_OF_FIELD) {
//..
}
//..
}
If you have already defined final int NO_OF_FIELD = 10, you can use the same instead of using the value 10 directly i.e. you should use NO_OF_FIELD instead of 10 in the following code:
if (data.length == NO_OF_FIELD) { //check and avoid indexOutOfBoundException
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
//...
else if ("person".equals(clazz) && data.length ==10) {
However, you also need to understand that && data.length ==10 is unnecessary here as you have already checked data.length == NO_OF_FIELD in the enclosing if condition.
I couldn't understand the rest of your points. If you clarify them, I'll be able to help you further.

I need to add the previous scenario in the second round.
Since the last set of data won't be captured, I need to set another new scenario to add it in. Thanks for the art sir.
Character character = null;
try (BufferedReader csvReader = new BufferedReader(new FileReader(csvFile));) {
String headerLine = csvReader.readLine(); //get rid of the header
//add each line to the arrayList
while ((line = csvReader.readLine()) != null) {
csvContents.add(line);
}
final int NO_OF_FIELDS = 10;
for(String csvLine : csvContents) {
String[] data = csvLine.split(csvSplit); // split by comma and remove redundant spaces
String clazz = data[0].toLowerCase();// cannot use word "class" as a variable
if (clazz.startsWith("scenario") && data.length == 1) {
// adding scenario after one set of data
// i.e second round adding the first round data
if (passengers.size() != 0 && pedestrians.size() != 0) {
Scenario scenario = new Scenario();
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
scenarios.add(scenario);
}
passengers = new ArrayList<Character>();
pedestrians = new ArrayList<Character>();
if (clazz.endsWith("green")) {
scenario.setLegalCrossing(true);
System.out.println("green light");
}
else if (clazz.endsWith("red")){
scenario.setLegalCrossing(false);
System.out.println("red light");
}
continue;
}
//...
Scenario scenario = new Scenario();
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
scenarios.add(scenario);
scenario.setPassengers(passengers);
scenario.setPedestrians(pedestrians);
Audit audit = new Audit();
audit.setScenario(scenarios);

manipulate and sort text file

I am working on a project where I have been given a text file and I have to add up the points for each team and printout the top 5 teams.
The text file looks like this:
FRAMae Berenice MEITE 455.455<br>
CHNKexin ZHANG 454.584<br>
UKRNatalia POPOVA 453.443<br>
GERNathalie WEINZIERL 452.162<br>
RUSEvgeny PLYUSHCHENKO 191.399<br>
CANPatrick CHAN 189.718<br>
CHNHan YAN 185.527<br>
CHNCheng & Hao 271.018<br>
ITAStefania & Ondrej 270.317<br>
USAMarissa & Simon 264.256<br>
GERMaylin & Daniel 260.825<br>
FRAFlorent AMODIO 179.936<br>
GERPeter LIEBERS 179.615<br>
JPNYuzuru HANYU 197.9810<br>
USAJeremy ABBOTT 165.654<br>
UKRYakov GODOROZHA 160.513<br>
GBRMatthew PARR 157.402<br>
ITAPaul Bonifacio PARKINSON 153.941<br>
RUSTatiana & Maxim 283.7910<br>
CANMeagan & Eric 273.109<br>
FRAVanessa & Morgan 257.454<br>
JPNNarumi & Ryuichi 246.563<br>
JPNCathy & Chris 352.003<br>
UKRSiobhan & Dmitri 349.192<br>
CHNXintong &Xun 347.881<br>
RUSYulia LIPNITSKAYA 472.9010<br>
ITACarolina KOSTNER 470.849<br>
JPNMao ASADA 464.078<br>
UKRJulia & Yuri 246.342<br>
GBRStacey & David 244.701<br>
USAMeryl &Charlie 375.9810<br>
CANTessa & Scott 372.989<br>
RUSEkaterina & Dmitri 370.278<br>
FRANathalie & Fabian 369.157<br>
ITAAnna & Luca 364.926<br>
GERNelli & Alexander 358.045<br>
GBRPenny & Nicholas 352.934<br>
USAAshley WAGNER 463.107<br>
CANKaetlyn OSMOND 462.546<br>
GBRJenna MCCORKELL 450.091<br>
The first three letters represent the team.
the rest of the text is the the competitors name.
The last digit is the score the competitor recived.
Code so far:
import java.util.Arrays;
public class project2 {
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] array = new String[41];
String[] info = new String[41];
String[] stats = new String[41];
String[] team = new String[41];
//.txt file location
FileInput fileIn = new FileInput();
fileIn.openFile("C:\\Users\\O\\Desktop\\turn in\\team.txt");
// txt file to array
int i = 0;
String line = fileIn.readLine();
array[i] = line;
i++;
while (line != null) {
line = fileIn.readLine();
array[i] = line;
i++;
}
//Splitting up Info/team/score into seprate arrays
for (int j = 0; j < 40; j++) {
team[j] = array[j].substring(0, 3).trim();
info[j] = array[j].substring(3, 30).trim();
stats[j] = array[j].substring(36).trim();
}
// Random stuff i have been trying
System.out.println(team[1]);
System.out.println(info[1]);
System.out.println(stats[1]);
MyObject ob = new MyObject();
ob.setText(info[0]);
ob.setNumber(7, 23);
ob.setNumber(3, 456);
System.out.println("Text is " + ob.getText() + " and number 3 is " + ob.getNumber(7));
}
}
I'm pretty much stuck at this point because I am not sure how to add each teams score together.

This looks like homework... First of all you need to examine how you are parsing the strings in the file.
You're saying: the first 3 characters are the country, which looks correct, but then you set the info to the 4th through the 30th characters, which isn't correct. You need to dynamically figure out where that ends and the score begins. There is a space between the "info" and the "stats," knowing that you could use String's indexOf function. (http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#indexOf(int))

Have a look at Maps.
A map is a collection that allows you to get data associated with a key in a very short time.
You can create a Map where the key is a country name, with value being the total points.
example:
Map<String,Integer> totalScore = new HashMap<>();
if (totalScore.containsKey("COUNTRYNAME"))
totalScore.put("COUNTRYNAME", totalScore.get("COUNTRYNAME") + playerScore)
else
totalScore.put("COUNTRYNAME",0)
This will add to the country score if the score exists, otherwise it will create a new totalScore for a country initialized to 0.

Not tested, but should give you some ideas:
public static void main(String... args)
throws Exception {
class Structure implements Comparable<Structure> {
private String team;
private String name;
private Double score;
public Structure(String team, String name, Double score) {
this.team = team;
this.name = name;
this.score = score;
}
public String getTeam() {
return team;
}
public String getName() {
return name;
}
public Double getScore() {
return score;
}
#Override
public int compareTo(Structure o) {
return this.score.compareTo(o.score);
}
}
File file = new File("path to your file");
List<String> lines = Files.readAllLines(Paths.get(file.toURI()), StandardCharsets.UTF_8);
Pattern p = Pattern.compile("(\\d+(?:\\.\\d+))");
List<Structure> structures = new ArrayList<Structure>();
for (String line : lines) {
Matcher m = p.matcher(line);
while (m.find()) {
String number = m.group(1);
String text = line.substring(0, line.indexOf(number) - 1);
double d = Double.parseDouble(number);
String team = text.substring(0, 3);
String name = text.substring(3, text.length());
structures.add(new Structure(team, name, d));
}
}
Collections.sort(structures);
List<Structure> topFive = structures.subList(0, 5);
for (Structure structure : topFive) {
System.out.println("Team: " + structure.getTeam());
System.out.println("Name: " + structure.getName());
System.out.println("Score: " + structure.getScore());
}
}
Just remove <br> from your file.

Loading file into memory
Your string splitting logic looks fine.
Create a class like PlayerData. Create one instance of that class for each row and set all the three fields into that using setters.
Keep adding the PlayerData objects into an array list.
Accumulating
Loop through the arraylist and accumulate the team scores into a hashmap. Create a Map to accumulate the team scores by mapping teamCode to totalScore.
Always store row data in a custom object for each row. String[] for each column is not a good way of holding data in general.

Take a look in File Utils. After that you can extract the content from last space character using String Utils e removing the <br> using it as a key for a TreeMap. Than you can have your itens ordered.
List<String> lines = FileUtils.readLines(yourFile);
Map<String, String> ordered = new TreeMap<>();
for (String s : lines) {
String[] split = s.split(" ");
String name = split[0].trim();
String rate = splt[1].trim().substring(0, key.length - 4);
ordered.put(rate, name);
}
Collection<String> rates = ordered.values(); //names ordered by rate
Of course that you need to adjust the snippet.

EMV TLV Java Function

I'm looking for a way to translate an EMV response with Java like with this online option:
http://www.emvlab.org/tlvutils/
where you put something like this EMV response:
6f3a8407a0000000031010a52f500b56495341204352454449548701015f2d086573656e707466729f12074352454449544f9f1101019f38039f1a02
and it will show you everything perfectly, I started doing something by myself but then I realize that maybe we could have two 9F38(PDOL) Strings not neccesary two same tags cuz I know it's impossible but maybe the value of a tag end in 9F and the start of the next tag would be 38 and that would give me an error... Now that I mention it, is that possible? cuz that was one of the main reasons why I stopped doing my own function..
Does any of you have written a function to do this already?
Thanks!

https://github.com/binaryfoo/emv-bertlv should do the trick.
Using your example, the following code:
List<DecodedData> decoded = new RootDecoder().decode("6f3a8407a0000000031010a52f500b56495341204352454449548701015f2d086573656e707466729f12074352454449544f9f1101019f38039f1a02", "EMV", "constructed");
new DecodedWriter(System.out).write(decoded, "");
Will output:
[6F (FCI template)] 8407A0000000031010A52F500B56495341204352454449548701015F...1A02
[84 (dedicated file name)] A0000000031010
[A5 (FCI proprietary template)] 500B56495341204352454449548701015F2D086573656E707466729F...1A02
[50 (application label)] VISA CREDIT
[87 (application priority indicator)] 01
[5F2D (language preference)] esenptfr
[9F12 (application preferred name)] CREDITO
[9F11 (issuer code table index)] 01
[9F38 (PDOL - Processing data object list)] 9F1A02
9F1A (terminal country code) 2 bytes

This project has code to deal with EMV data http://code.google.com/p/javaemvreader/

You are on the right track. You can easily build your own EMV parser using the technique call TLV (Tag Length Value). Your raw data always comes back with a Tag, then after the tag is the length, using the length can get you the value.
So create three methods
method 1: Contains all the short tags
method 2: Contains all the long tags
method 3: Contains all the proprietary tags
So when you pass in your raw emv tag:
6f3a8407a0000000031010a52f500b56495341204352454449548701015f2d086573656e707466729f12074352454449544f9f1101019f38039f1a02
Loop through all those three methods, it will give you all the nice information that you need.

Use below function which will gives you hashmap of TLV value
public LinkedHashMap parseBERTLVTag(String tlv) throws DecoderException
{
if(tlv==null || "".equalsIgnoreCase(tlv)){
return null;
}
System.out.println("============= START ["+tlv+"]==================");
boolean inTagRead= true;
Map<String,String> tags= new HashMap<>();
StringBuilder _tmp = new StringBuilder();
String lastTag = "";
int old_index = 0;
boolean isFirstTagByte = true;
int len = 0;
boolean more=true;
String data = "";
while (more)
{
len = 0;
String hByte = tlv.substring(old_index,(old_index = old_index+2));
if(inTagRead)
{
if(isLastTagByte(hByte, isFirstTagByte))
{
inTagRead=false;
_tmp.append(hByte);
lastTag = _tmp.toString();
System.out.println("Tag["+lastTag+"]");
tags.put(lastTag, null);
_tmp= new StringBuilder();
}else
{
_tmp.append(hByte);
}
isFirstTagByte = false;
}else//Length
{
isFirstTagByte = true;
if(isLastLengthByte(hByte)) {
inTagRead=true;
_tmp.append(hByte);
len = Integer.parseInt(_tmp.toString(), 16 );
//read len*2
System.out.println(" Length ["+len+"]");
data = tlv.substring(old_index, (old_index = old_index+len*2));
String tmpData= lastTag+":"+_tmp.toString()+":h"+data;
System.out.println(" Data ["+tmpData+"]");
_tmp = new StringBuilder();
tags.put(lastTag, tmpData);
}else
{
_tmp.append(hByte);
}
}
more= tlv.length()<=old_index?false:true;
System.out.println("tag "+lastTag+" value "+data+" length "+len);
if(lastTag.length() > 0 && data.length() > 0 && len > 0){
if(!map.containsKey(lastTag)){
map.put(lastTag,new TLVModel().setTag(lastTag).setLength(len).setValue(data));
}
}
}//END OF WHILE
System.out.println("------------ as MAP ---------------------");
System.out.println("size "+map.size());
for (Map.Entry mp:map.entrySet()){
System.out.println("key "+mp.getKey()+" value "+mp.getValue());
}
return map.size() > 0 ? map : null;
}

Extracting data from a collection in Java

I have a csv dataset like this:
A, 10, USA
B,30, UK
C,4,IT
A,20,UK
B,10,USA
I want to read this csv lines and provide the following output:
A has ran 30 miles with average of 15.
B has ran 30 miles with average of 20.
C has ran 4 miles with average of 4.
I want to achieve this in Java. I have done this in C# by using Linq:
var readlines = File.ReadAllLines(filename);
var query = from lines in readlines
let data = lines.Split(',')
select new
{
Name = data[0],
Miles = data[1],
};
var values = query.GroupBy(x => new {x.Name}).Select(group => new { Person = group.Key, Events = group.Sum(g =>Convert.ToDouble(g.Miles)) ,Count = group.Count() });
I am looking to do this in Java, and I am not sure if I can do this without using any third party library or not? Any ideas?
So far, my code looks like this in Java:
CSVReader reader = new CSVReader(new FileReader(filename));
java.util.List<String[]> content = reader.readAll();
String[] row = null;
for(Object object:content)
{
row = (String[]) object;
String Name = row[0];
String Miles = row[1];
System.out.printf("%s has ran %s miles %n",Name,Miles);
}
reader.close();
}
I am looking for a nice way to get the total milage value for each name to calculate for the average.

As a C# developer, it is hard sometimes not to miss the features of linq. But as Farlan suggested you could do something like this:
CSVReader reader = new CSVReader(new FileReader(filename));
java.util.List<String[]> content = reader.readAll();
Map<String, Group> groups = new HashMap<>();
for(String[] row : content)
{
String Name = row[0];
String Miles = row[1];
System.out.printf("%s has ran %s miles %n", Name, Miles);
if (groups.containsKey(Name)){
groups.get(Name).Add(Double.valueOf(Miles));
} else {
Group g = new Group();
g.Add(Double.valueOf(Miles));
groups.put(Name, g);
}
}
reader.close();
for (String name : groups.keySet())
{
System.out.println(name + " ran " + groups.get(name).total() + " with avg of " + groups.get(name).average());
}
}
class Group {
private List<Double> miles;
public Group()
{
miles = new ArrayList<>();
}
public Double total(){
double sum = 0;
for (Double mile : miles)
{
sum += mile;
}
return sum;
}
public Double average(){
if (miles.size() == 0)
return 0d;
return total() / miles.size();
}
public void Add(Double m){
miles.add(m);
}
}

Use Java's BufferedReader class:
BufferedReader in = new BufferedReader(new FileReader("your.csv"));
String line;
while ( (line = in.readLine()) != null) {
String [] fields = line.split(",");
System.out.println(fields[0] + " has ran " + fields[1] + " miles with average " + fields[2]);
}

There are quite a few ways to do this, some long-winded approaches, some shorter. The issue is that Java can be very verbose for doing simple tasks, so the better approaches can be a bit uglier.
The example below shows you exactly how to achieve this, par the printing. Bear in mind however, it might not be the best approach but I feel its more of the easier ones to read and comprehend.
final File csvFile = new File("filename.csv");
final Scanner reader = new Scanner(csvFile);
final Map<String, Integer> info = new HashMap<>(); //Store the data
//Until there is are no more lines, continue
while (reader.hasNextLine()) {
final String[] data = reader.nextLine().split(","); // data[0] = A. [1] = 10. [2] = USA
final String alpha = data[0];
if (!info.containsKey(alpha)) {
info.put(alpha, Integer.parseInt(data[1]));
} else {
int miles = info.get(alpha);
info.put(alpha, miles + Integer.parseInt(data[1]));
}
}
reader.close();
The steps involved are simple:
Step 1 - Read the file.
By passing a File into the Scanner object, you set the target parsing to the File and not the console. Using the very neat hasNextLine() method, you can continually read each line until no more exist. Each line is then split by a comma, and stored in a String array for reference.
Step 2 - Associating the data.
As you want to cumulatively add the integers together, you need a way to associate already passed in letters with the numbers. A heavyweight but clean way of doing this is to use a HashMap. The Key which it takes is going to be a String, specifically A B or C. By taking advantage of the fact the Key is unique, we can use the O(1) containsKey(String) method to check if we've already read in the letter. If its new, add it to the HashMap and save the number with it. If however, the letter has been seen before, we find the old value, add it with the new one and overwrite the data inside the HashMap.
All you need to do now is print out the data. Feel free to take a different approach, but I hope this is a clear example of how you CAN do it in Java.

Maybe you could try this Java library: https://code.google.com/p/qood/
It handles data without any getter/setters, so it's more flexible than LINQ.
in your case, file "D:/input.csv" has 3 columns:
NAME,MILES,COUNTRY
A, 10, USA
B,30, UK
C,4,IT
A,20,UK
B,10,USA
the query code would be:
final QModel raw = QNew.modelCSV("D:/input.csv")
.debug(-1);//print out what read from CSV
raw.query()
.selectAs("OUTPUT",
"CONCAT(NAME,' has ran ',SUM(MILES),' miles with average of ',MEAN(MILES),'.')")
.groupBy("NAME")
.result().debug(-1)//print out the result
.to().fileCSV("D:/output.csv", "UTF-8");//write to another CSV file