CSV_JSON/src/main/java/main.java - master - Letta21/CSV_XM_JSON

CSV_JSON/src/main/java/main.java
100 строк4 KB
Letta21
update CSV_JSON/src/main/java/main.java
15 янв 2026, 02:11
15 янв 2026, 02:113e74319
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;
import com.opencsv.CSVReader;
import com.opencsv.bean.ColumnPositionMappingStrategy;
import com.opencsv.bean.CsvToBean;
import com.opencsv.bean.CsvToBeanBuilder;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

class Main {
    public static void main(String[] args) {
        // Задача 1 (CSV) 
        String[] columnMapping = {"id", "firstName", "lastName", "country", "age"};
        List<Employee> listFromCsv = parseCSV(columnMapping, "data.csv");
        String jsonFromCsv = listToJson(listFromCsv);
        writeString(jsonFromCsv, "data.json");

        // Задача 2 (XML) 
        List<Employee> listFromXml = parseXML("data.xml");
        String jsonFromXml = listToJson(listFromXml);
        writeString(jsonFromXml, "data2.json");
    }

    private static List<Employee> parseXML(String fileName) {
        List<Employee> employeeList = new ArrayList<>();
        try {
            // Создаем фабрику и билдер для чтения документа
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(new File(fileName));

            // Получаем корневой элемент документа 
            Node root = doc.getDocumentElement();

            // Получаем список дочерних узлов (узлы <employee>)
            NodeList nodeList = root.getChildNodes();

            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);

                //  интересуют только узлы-элементы  
                if (Node.ELEMENT_NODE == node.getNodeType()) {
                    Element element = (Element) node;

                    // Извлекаем данные из тегов  
                    long id = Long.parseLong(element.getElementsByTagName("id").item(0).getTextContent());
                    String firstName = element.getElementsByTagName("firstName").item(0).getTextContent();
                    String lastName = element.getElementsByTagName("lastName").item(0).getTextContent();
                    String country = element.getElementsByTagName("country").item(0).getTextContent();
                    int age = Integer.parseInt(element.getElementsByTagName("age").item(0).getTextContent());

                    // Создаем объект и добавляем в список
                    employeeList.add(new Employee(id, firstName, lastName, country, age));
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return employeeList;
    }

    // Методы из первой задачи

    private static List<Employee> parseCSV(String[] columnMapping, String fileName) {
        try (CSVReader csvReader = new CSVReader(new FileReader(fileName))) {
            ColumnPositionMappingStrategy<Employee> strategy = new ColumnPositionMappingStrategy<>();
            strategy.setType(Employee.class);
            strategy.setColumnMapping(columnMapping);
            CsvToBean<Employee> csv = new CsvToBeanBuilder<Employee>(csvReader)
                    .withMappingStrategy(strategy)
                    .build();
            return csv.parse();
        } catch (IOException e) {
            return null;
        }
    }

    private static String listToJson(List<Employee> list) {
        Gson gson = new GsonBuilder().setPrettyPrinting().create();
        Type listType = new TypeToken<List<Employee>>() {}.getType();
        return gson.toJson(list, listType);
    }

    private static void writeString(String json, String fileName) {
        try (FileWriter file = new FileWriter(fileName)) {
            file.write(json);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}