How to process csv.file data after parsing in java

我的未来我决定 提交于 2020-06-29 03:54:19


I am new to java and practicing processing csv file. I've already successfully parsed the csv file, saved it in an array, and got rid of the header.

The file looks like this:

class, gender, age, bodyType, profession, pregnant, species, isPet, role
scenario:green,   ,         ,           ,         ,        ,      ,
person, female, 24, average , doctor    , FALSE   ,        ,      , passenger
animal, male  ,  4          ,           , FALSE   , dog    , true , pedestrian

the column without a string is empty in the file. Like the species and isPet above.

Now, I want to iterate through this array and create the instance, and it's too complex for me to figure it out.

For example, I have a Scenario class with the constructor:

Scenario(ArrayList<Character> passenger, ArrayList<Character> pedestrian, boolean greenOrRed)

and before creating scenario instance, I have to create Character by the constructor with two different subclasses Person and Animal. Further, arrange them into two separate groups, which are passenger and pedestrian:

Person(Gender gender, int age, Profession profession, BodyType bodyType, boolean isPregnant)
Animal(Gender gender, int age, BodyType bodyType, String species)

What I've tried like this:

public void loadCsv() throws IOException {

    String csvFile = "config.csv";
    String line = "";
    String csvSplit = ",";
    try (BufferedReader csvReader = new BufferedReader(new FileReader(csvFile));) {
        String headerLine = csvReader.readLine();
        while ((line = csvReader.readLine()) != null) {
            for (String token : data) {
                if (!token.isEmpty() && token.equals("scenario:green")) {
                    scenario.setLegalCrossing(true); //pass to setter works
                    //how to process with next token?

    } catch (FileNotFoundException e) {


And I've referred to this post: How to easily process CSV file to List<MyClass>

Any help or hint is highly appreciated.


The order is like this:

First, set the boolean greenOrRed from the Scenario class.

//if the class equals to Scenario:green

Second is to generate Person and Animal

//if class equals to Person
Person people =Person(Gender gender, int age, Profession profession, BodyType bodyType, boolean isPregnant)
//if class equals to Animal
Animal animal = Animal(Gender gender, int age, BodyType bodyType, String species)

Third, add them into superclass array:

ArrayList<Character> passenger = new ArrayList<Character>();
ArrayList<Character> pedestrian = new ArrayList<Character>();

passenger.add(people); // if role equals passenger
pedestrian.add(animal); // if role equals pedestrian

Finally, add passenger and pedestrian into Scenario constructor with the first step boolean value to form an instance.

Scenario singleScenario = Scenario(passenger, pedestrian, legalCrossing)


Please review the following example of parsing your sample data (all details of reading the CSV file and skipping the header are omitted):

List<String> csvContents = Arrays.asList(
//  "class, gender, age, bodyType, profession, pregnant, species, isPet, role",
    "person, female, 24, average , doctor    , FALSE   ,        ,      , passenger",
    "animal, male  ,  4,         ,           , FALSE   , dog    , true , pedestrian"

Scenario scenario = null;
List<Character> passengers = new ArrayList<>();
List<Character> pedestrians = new ArrayList<>();

for (String line : csvContents) {
    String[] data = line.split("\\s*,\\s*"); // split by comma and remove redundant spaces
    Character character = null;
    String clazz = data[0].toLowerCase();
    if (clazz.startsWith("scenario")) {
        scenario = new Scenario();
    } else if ("person".equals(clazz)) {
        character = new Person(data[1], Integer.parseInt(data[2]), data[3], data[8], data[4], Boolean.parseBoolean(data[5]));
    } else if ("animal".equals(clazz)) {
        character = new Animal(data[1], Integer.parseInt(data[2]), data[3], data[8], data[6], Boolean.parseBoolean(data[7]));

    String role = data[8].toLowerCase();
    if ("passenger".equals(role)) {
        if (null != character) passengers.add(character);
    } else if ("pedestrian".equals(role)) {
        if (null != character) pedestrians.add(character);

System.out.println("passengers: " + passengers);
System.out.println("pedestrians: " + pedestrians);

if (null != scenario) {


passengers: [Person(super=Character(gender=female, age=24, bodyType=average, role=passenger), profession=doctor, isPregnant=false)]
pedestrians: [Animal(super=Character(gender=male, age=4, bodyType=, role=pedestrian), species=dog, isPet=true)]

You should be able to use this code snippet as a reference and modify it according to your needs.