java/org/example/CsvJsonParser.java - master - siman_coder/JUnit

java/org/example/CsvJsonParser.java
142 строки5 KB
siman_coder
Create: CsvJsonParser.java, Employee.java, Main.java, CsvJsonParserTest.java, build.gradle, data.csv, data.json, data.xml, data2.json
07 июл 2026, 11:23
Верифицирован
07 июл 2026, 11:231a342fc
package org.example;

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 java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Type;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

public class CsvJsonParser {

    // Парсинг CSV
    public static List<Employee> parseCSV(String[] columnMapping, String fileName) {
        List<Employee> employees = null;

        try (CSVReader csvReader = new CSVReader(new FileReader(fileName))) {
            ColumnPositionMappingStrategy<Employee> strategy = new ColumnPositionMappingStrategy<>();
            strategy.setType(Employee.class);
            strategy.setColumnMapping(columnMapping);

            CsvToBean<Employee> csvToBean = new CsvToBeanBuilder<Employee>(csvReader)
                    .withMappingStrategy(strategy)
                    .build();

            employees = csvToBean.parse();
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }

        return employees;
    }

    // Парсинг XML (ручной)
    public static List<Employee> parseXML(String fileName) {
        List<Employee> employees = new ArrayList<>();

        try {
            if (!Files.exists(Paths.get(fileName))) {
                return employees;
            }

            String xmlContent = new String(Files.readAllBytes(Paths.get(fileName)));
            String[] parts = xmlContent.split("</employee>");

            for (String part : parts) {
                if (part.contains("<employee>")) {
                    String idStr = extractTagContent(part, "id");
                    String firstName = extractTagContent(part, "firstName");
                    String lastName = extractTagContent(part, "lastName");
                    String country = extractTagContent(part, "country");
                    String ageStr = extractTagContent(part, "age");

                    if (idStr != null && firstName != null && lastName != null &&
                            country != null && ageStr != null) {

                        long id = Long.parseLong(idStr.trim());
                        int age = Integer.parseInt(ageStr.trim());

                        Employee employee = new Employee(id, firstName, lastName, country, age);
                        employees.add(employee);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }

        return employees;
    }

    private static String extractTagContent(String xml, String tag) {
        String openTag = "<" + tag + ">";
        String closeTag = "</" + tag + ">";

        int startIndex = xml.indexOf(openTag);
        if (startIndex == -1) {
            return null;
        }

        startIndex += openTag.length();
        int endIndex = xml.indexOf(closeTag, startIndex);

        if (endIndex == -1) {
            return null;
        }

        return xml.substring(startIndex, endIndex).trim();
    }

    // Преобразование списка в JSON
    public static String listToJson(List<Employee> list) {
        GsonBuilder builder = new GsonBuilder().setPrettyPrinting();
        Gson gson = builder.create();

        Type listType = new TypeToken<List<Employee>>() {}.getType();
        return gson.toJson(list, listType);
    }

    // Парсинг JSON в список
    public static List<Employee> jsonToList(String fileName) {
        List<Employee> employees = new ArrayList<>();

        try {
            if (!Files.exists(Paths.get(fileName))) {
                return employees;
            }

            String jsonContent = new String(Files.readAllBytes(Paths.get(fileName)));
            Gson gson = new Gson();
            Type listType = new TypeToken<List<Employee>>() {}.getType();
            employees = gson.fromJson(jsonContent, listType);
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }

        return employees;
    }

    // Запись JSON в файл
    public static boolean writeString(String json, String fileName) {
        try (FileWriter fileWriter = new FileWriter(fileName)) {
            fileWriter.write(json);
            return true;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }
}