Добавлено формирование CSV файла

people.csv

@@ -0,0 +1,11 @@
+first_name,last_name,day_of_birth,month_of_birth,year_of_birth
+Юлия,Авдеев,22,JULY,1978
+София,Киселев,27,MAY,2005
+Валентин,Поляков,10,MAY,1983
+Аркадий,Куликов,10,OCTOBER,1981
+Валерий,Матвеев,15,AUGUST,1992
+Сергей,Баранова,19,APRIL,1979
+Надежда,Зуев,5,JANUARY,1984
+Матвей,Крылова,22,SEPTEMBER,1980
+Олег,Лобанова,17,FEBRUARY,1999
+Анжелика,Ширяева,11,AUGUST,1972

pom.xml

@@ -27,6 +27,17 @@
             <version>5.8.1</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.github.javafaker</groupId>
+            <artifactId>javafaker</artifactId>
+            <version>1.0.2</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.24.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 </project>

src/main/java/org/writer/CsvColumn.java

@@ -0,0 +1,19 @@
+package org.writer;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Аннотация для пометки полей, которые должны попадать в CSV. * Поле order используется для задания порядка колонок в выходном файле.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface CsvColumn {
+
+    String name() default "";
+
+    int order() default Integer.MAX_VALUE;
+
+}

src/main/java/org/writer/CsvWritable.java

@@ -0,0 +1,117 @@
+package org.writer;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.*;
+
+import static java.nio.file.StandardOpenOption.CREATE;
+import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
+import static java.util.stream.Collectors.joining;
+
+/**
+ * Реализация Writable, сохраняющая список объектов в CSV файл
+ */
+public class CsvWritable implements Writable {
+
+    private final String separator;
+
+    /**
+     * Создаёт CsvWritable с разделителем по умолчанию (запятая).
+     */
+    public CsvWritable() {
+        this(",");
+    }
+
+    /**
+     * Создаёт CsvWritable с указанным разделителем.
+     *
+     * @param separator строка-разделитель
+     */
+    public CsvWritable(String separator) {
+        if (StringUtils.isEmpty(separator)) {
+            throw new IllegalArgumentException("Сепаратор не заполнен");
+        }
+        this.separator = separator;
+    }
+
+    /**
+     * Сохраняет список объектов в CSV файл
+     *
+     * @param data     список объектов одного типа
+     * @param fileName путь к файлу (создаётся/перезаписывается)
+     */
+    @Override
+    public void writeToFile(List<?> data, String fileName) {
+        if (data == null || data.isEmpty()) {
+            throw new IllegalArgumentException("Данные не заполнены");
+        }
+        Class<?> clazz = data.get(0).getClass();
+        List<Field> columns = getAnnotatedFields(clazz);
+        List<String> header = columns.stream().map(f -> {
+            CsvColumn ann = f.getAnnotation(CsvColumn.class);
+            return ann.name().isEmpty()
+                    ? f.getName()
+                    : ann.name();
+        }).toList();
+        Path path = Path.of(fileName);
+        try (BufferedWriter writer = Files.newBufferedWriter(path, CREATE, TRUNCATE_EXISTING)) {
+            writer.write(String.join(separator, header));
+            writer.newLine();
+            for (Object obj : data) {
+                List<String> row = new ArrayList<>();
+                for (Field field : columns) {
+                    field.setAccessible(true);
+                    Object value = field.get(obj);
+                    row.add(escapeCsv(formatValue(value)));
+                }
+                writer.write(String.join(separator, row));
+                writer.newLine();
+            }
+        } catch (IOException | IllegalAccessException e) {
+            throw new RuntimeException("Ошибка записи CSV файла", e);
+        }
+    }
+
+    private List<Field> getAnnotatedFields(Class<?> clazz) {
+        Field[] fields = clazz.getDeclaredFields();
+        return Arrays.stream(fields)
+                .filter(f -> f.isAnnotationPresent(CsvColumn.class))
+                .sorted(Comparator.comparingInt(f -> f.getAnnotation(CsvColumn.class).order()))
+                .toList();
+    }
+
+    private String formatValue(Object value) {
+        if (value == null) {
+            return "";
+        }
+        if (value instanceof Enum<?>) {
+            return ((Enum<?>) value).name();
+        }
+        if (value instanceof Collection<?>) {
+            return ((Collection<?>) value).stream()
+                    .map(Objects::toString)
+                    .collect(joining(";"));
+        }
+        return value.toString();
+    }
+
+    private String escapeCsv(String field) {
+        if (StringUtils.isEmpty(field)) {
+            return "";
+        }
+        boolean needQuotes = field.contains(",")
+                || field.contains("\"")
+                || field.contains("\n")
+                || field.contains("\r")
+                || field.contains(";");
+        String escaped = field.replace("\"", "\"\"");
+        return needQuotes
+                ? "\"" + escaped + "\""
+                : escaped;
+    }
+}

src/main/java/org/writer/Main.java

@@ -1,7 +1,40 @@
 package org.writer;
 
+import com.github.javafaker.Faker;
+import org.writer.model.Months;
+import org.writer.model.Person;
+import org.writer.model.Student;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.IntStream;
+
 public class Main {
     public static void main(String[] args) {
-        System.out.println("Hello world!");
+        Faker faker = new Faker(new Locale("ru"));
+        List<Person> people = IntStream.range(0, 10)
+                .mapToObj(i -> Person.builder()
+                        .firstName(faker.name().firstName())
+                        .lastName(faker.name().lastName())
+                        .dayOfBirth(faker.number().numberBetween(1, 28))
+                        .monthOfBirth(Months.values()[faker.number().numberBetween(0, Months.values().length)])
+                        .yearOfBirth(faker.number().numberBetween(1970, 2010))
+                        .build())
+                .toList();
+        List<Student> students = new ArrayList<>();
+        for (int i = 0; i < 5; i++) {
+            List<String> scores = IntStream.range(0, 4)
+                    .mapToObj(j -> String.valueOf(faker.number().numberBetween(50, 100)))
+                    .toList();
+            students.add(Student.builder()
+                    .name(faker.name().fullName())
+                    .score(scores)
+                    .build());
+        }
+        Writable writer = new CsvWritable();
+        writer.writeToFile(people, "people.csv");
+        writer.writeToFile(students, "students.csv");
+        System.out.println("CSV файлы (people.csv, students.csv) успешно заполнены");
     }
 }

src/main/java/org/writer/model/Person.java

@@ -3,20 +3,26 @@
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
+import org.writer.CsvColumn;
 
 @Data
 @Builder
 @AllArgsConstructor
 public class Person {
 
+    @CsvColumn(name = "first_name", order = 1)
     private String firstName;
 
+    @CsvColumn(name = "last_name", order = 2)
     private String lastName;
 
+    @CsvColumn(name = "day_of_birth", order = 3)
     private int dayOfBirth;
 
+    @CsvColumn(name = "month_of_birth", order = 4)
     private Months monthOfBirth;
 
+    @CsvColumn(name = "year_of_birth", order = 5)
     private int yearOfBirth;
 
 }

src/main/java/org/writer/model/Student.java

@@ -3,6 +3,7 @@
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
+import org.writer.CsvColumn;
 
 import java.util.List;
 
@@ -11,7 +12,9 @@
 @AllArgsConstructor
 public class Student {
 
+    @CsvColumn(name = "name", order = 1)
     private String name;
 
+    @CsvColumn(name = "score", order = 2)
     private List<String> score;
 }

src/test/java/org/writer/CsvWritableTest.java

@@ -0,0 +1,68 @@
+package org.writer;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.writer.model.Months;
+import org.writer.model.Person;
+import org.writer.model.Student;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class CsvWritableTest {
+
+    private Writable writable;
+
+    @TempDir
+    Path tempDir;
+
+    @BeforeEach
+    void setUp() {
+        writable = new CsvWritable();
+    }
+
+    @Test
+    void writesPersonCsv() throws IOException {
+        Person p1 = Person.builder()
+                .firstName("Ivan")
+                .lastName("Petrov")
+                .dayOfBirth(5)
+                .monthOfBirth(Months.MARCH)
+                .yearOfBirth(1990)
+                .build();
+        Person p2 = Person.builder()
+                .firstName("Anna")
+                .lastName("Ivanova")
+                .dayOfBirth(12)
+                .monthOfBirth(Months.DECEMBER)
+                .yearOfBirth(1985)
+                .build();
+        Path file = tempDir.resolve("persons.csv");
+
+        writable.writeToFile(List.of(p1, p2), file.toString());
+
+        String content = Files.readString(file);
+        assertThat(content).contains("first_name,last_name,day_of_birth,month_of_birth,year_of_birth");
+        assertThat(content).contains("Ivan,Petrov,5,MARCH,1990");
+        assertThat(content).contains("Anna,Ivanova,12,DECEMBER,1985");
+    }
+
+    @Test
+    void writesStudentCsvWithListField() throws IOException {
+        Student s = Student.builder().name("Sidor Sidorov").score(List.of("80", "90", "75")).build();
+        Path file = tempDir.resolve("students.csv");
+
+        writable.writeToFile(List.of(s), file.toString());
+
+        String content = Files.readString(file);
+        assertThat(content).contains("name,score");
+        assertThat(content).contains("Sidor Sidorov");
+        assertThat(content).contains("80;90;75");
+    }
+
+}

students.csv

@@ -0,0 +1,6 @@
+name,score
+Илья Алексеев,"97;54;82;61"
+Валентин Анисимов,"60;67;53;55"
+Ирина Мельникова,"87;57;88;67"
+Анна Леонидовна Романова,"64;64;63;63"
+Мишина Клавдия,"74;81;98;89"