src/main/java/service/Parser.java - master - Shcod/java-core-Parser

src/main/java/service/Parser.java
121 строка4 KB
Shcod
first commit
10 авг 2026, 01:10
10 авг 2026, 01:104aa8947
package service;

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 entity.Employee;
import org.json.simple.JSONArray;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.*;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

public class Parser {

    public List<Employee> parseCSV(String[] columnMapping, String filename) {
        List<Employee> employeeList;
        try (CSVReader reader = new CSVReader(new FileReader(filename))) {

            ColumnPositionMappingStrategy<Employee> strategy = new ColumnPositionMappingStrategy<>();
            strategy.setType(Employee.class);
            strategy.setColumnMapping(columnMapping);

            CsvToBean<Employee> csv = new CsvToBeanBuilder<Employee>(reader).withMappingStrategy(strategy).build();
            employeeList = csv.parse();

        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return employeeList;
    }

    public List<Employee> parseXML(String filename) {
        List<Employee> employeeList = new ArrayList<>();
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(new File(filename));
            Node root = doc.getDocumentElement();
            NodeList nodeList = root.getChildNodes();

            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);
                if (node.getNodeType() == Node.ELEMENT_NODE) {
                    Element element = (Element) node;
                    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());
                    employeeList.add(new Employee(id, firstName, lastName, country, age));
                }
            }
        } catch (ParserConfigurationException | SAXException | IOException e) {
            throw new RuntimeException(e);
        }
        return employeeList;
    }

    public String listToJson(List<Employee> employees) {
        GsonBuilder builder = new GsonBuilder();
        Gson gson = builder.create();
        Type listType = new TypeToken<List<Employee>>() {
        }.getType();
        return gson.toJson(employees, listType);
    }

    public List<Employee> jsonToList(String path) {
        List<Employee> result = new ArrayList<>();
        JSONParser parser = new JSONParser();
        try {
            JSONArray arr = (JSONArray) parser.parse(readString(path));
            GsonBuilder builder = new GsonBuilder();
            Gson gson = builder.create();
            for (Object o : arr) {
                result.add(gson.fromJson(o.toString(), Employee.class));
            }
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }

        return result;
    }

    public String readString(String path) {
        StringBuilder sb = new StringBuilder();
        try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return sb.toString();
    }


    public void writeString(String path, String json) {
        try (FileWriter writer = new FileWriter(path)) {
            writer.write(json);
            writer.flush();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}