chore: organize homework into first-part directory

2026-09-12 17:46:39 +04:00
parent cd4bc632ed
commit 58459cc92b
80 changed files with 0 additions and 0 deletions
@@ -0,0 +1,39 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.example</groupId>
+  <artifactId>student-reader</artifactId>
+  <packaging>jar</packaging>
+  <version>1.0-SNAPSHOT</version>
+  <name>student-reader</name>
+  <url>http://maven.apache.org</url>
+  <dependencies>
+
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>2.20.0</version>
+    </dependency>
+
+    <dependency>
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jsr310</artifactId>
+      <version>2.20.0</version>
+    </dependency>
+
+  </dependencies>
+
+  <properties>
+    <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
+  </properties>
+
+</project>
@@ -0,0 +1,71 @@
+package com.example;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.time.Year;
+import java.util.Comparator;
+import java.util.List;
+
+public class App {
+
+  public static void main(String[] args) {
+
+    try {
+
+      Path studentsJsonFile = Path.of("students.json");
+      List<Student> students = StudentReader.read(studentsJsonFile);
+
+      // Условие использования одного stream сохраняется
+      students.stream()
+
+          // Вывести в консоль каждого студента (переопределите toString)
+          .peek(System.out::println)
+
+          // Получить для каждого студента список книг
+          .map(s -> s.getBooks()) // Stream<List<Book>>
+
+          // Получить книги
+          .flatMap(List::stream) // Stream<Book>;
+
+          // Oтсортировать книги по количеству страниц (Не забывайте про условия для сравнения
+          // объектов)
+          .sorted(Comparator.comparingInt(Book::getPageCount))
+
+          // Оставить только уникальные книги
+          .distinct()
+
+          // Отфильтровать книги, оставив только те, которые были выпущены после 2000 года
+          .filter(b -> b.getPublishYear().isAfter(Year.of(2000)))
+
+          // Ограничить стрим на 3 элементах
+          .limit(3)
+
+          // Получить из книг годы выпуска
+          .map(Book::getPublishYear)
+
+          // При помощи методов короткого замыкания (почитайте самостоятельно что это такое) вернуть
+          // Optional от года
+          .findFirst()
+
+          // При помощи методов получения значения из Optional вывести в консоль год выпуска
+          // найденной книги, либо запись о том, что такая книга отсутствует
+          .ifPresentOrElse(
+              year -> System.out.println("Год выпуска: " + year),
+              () -> System.out.println("Подходящая книга отсутствует"));
+
+    } catch (IOException e) {
+
+      System.err.println("Сударь, вы передали неправильный файл!");
+      e.printStackTrace();
+      System.exit(1);
+
+    } catch (Exception e) {
+
+      System.err.println("Ну тут мои полномочии всё!");
+      e.printStackTrace();
+      System.exit(1);
+    }
+
+    System.out.println("Выполнение программы завершено");
+  }
+}
@@ -0,0 +1,72 @@
+package com.example;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import java.time.Year;
+import java.util.Objects;
+
+public class Book {
+
+  @JsonCreator
+  public Book(
+      @JsonProperty("author") String author,
+      @JsonProperty("title") String title,
+      @JsonProperty("publishYear") Year publishYear,
+      @JsonProperty("pageCount") int pageCount) {
+
+    this.author = author;
+    this.title = title;
+    this.publishYear = publishYear;
+    this.pageCount = pageCount;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+
+    if (!(o instanceof Book book)) {
+      return false;
+    }
+
+    return pageCount == book.pageCount
+        && author.equals(book.author)
+        && title.equals(book.title)
+        && publishYear.equals(book.publishYear);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(author, title, publishYear, pageCount);
+  }
+
+  @Override
+  public String toString() {
+    return "Book{"
+        + "author='"
+        + author
+        + '\''
+        + ", title='"
+        + title
+        + '\''
+        + ", publishYear="
+        + publishYear
+        + ", pageCount="
+        + pageCount
+        + '}';
+  }
+
+  public int getPageCount() {
+    return pageCount;
+  }
+
+  public Year getPublishYear() {
+    return publishYear;
+  }
+
+  private final String author;
+  private final String title;
+  private final Year publishYear;
+  private final int pageCount;
+}
@@ -0,0 +1,47 @@
+package com.example;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.List;
+
+public class Student {
+
+  @JsonCreator
+  public Student(
+      @JsonProperty("name") String name,
+      @JsonProperty("surname") String surname,
+      @JsonProperty("books") List<Book> books) {
+
+    this.name = name;
+    this.surname = surname;
+    this.books = List.copyOf(books);
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder booksString = new StringBuilder();
+
+    for (Book book : books) {
+      booksString.append("\n    ").append(book);
+    }
+
+    return "Student{\n"
+        + "  name='"
+        + name
+        + "'\n"
+        + "  surname='"
+        + surname
+        + "'\n"
+        + "  books="
+        + booksString
+        + "\n}";
+  }
+
+  public List<Book> getBooks() {
+    return books;
+  }
+
+  private final String name;
+  private final String surname;
+  private final List<Book> books;
+}
@@ -0,0 +1,20 @@
+package com.example;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.List;
+
+public final class StudentReader {
+
+  public static List<Student> read(Path path) throws IOException {
+    return MAPPER.readValue(path.toFile(), new TypeReference<List<Student>>() {});
+  }
+
+  private StudentReader() {}
+
+  private static final ObjectMapper MAPPER =
+      new ObjectMapper().registerModule(new JavaTimeModule());
+}
@@ -0,0 +1,110 @@
+[
+  {
+    "name": "Aaa",
+    "surname": "Bbb",
+    "books": [
+      {
+        "author": "Aaa Aaa",
+        "title": "Book Aaa",
+        "publishYear": "2027",
+        "pageCount": 500
+      },
+      {
+        "author": "Bbb Bbb",
+        "title": "Book Bbb",
+        "publishYear": "2018",
+        "pageCount": 200
+      },
+      {
+        "author": "Ccc Ccc",
+        "title": "Book Ccc",
+        "publishYear": "2024",
+        "pageCount": 900
+      },
+      {
+        "author": "Ddd Ddd",
+        "title": "Book Ddd",
+        "publishYear": "2015",
+        "pageCount": 400
+      },
+      {
+        "author": "Ddd Ddd",
+        "title": "Book Ddd",
+        "publishYear": "2015",
+        "pageCount": 400
+      }
+    ]
+  },
+  {
+    "name": "Ccc",
+    "surname": "Ddd",
+    "books": [
+      {
+        "author": "Eee Eee",
+        "title": "Book Eee",
+        "publishYear": "1999",
+        "pageCount": 300
+      },
+      {
+        "author": "Fff Fff",
+        "title": "Book Fff",
+        "publishYear": "2030",
+        "pageCount": 1200
+      },
+      {
+        "author": "Ggg Ggg",
+        "title": "Book Ggg",
+        "publishYear": "2005",
+        "pageCount": 100
+      },
+      {
+        "author": "Hhh Hhh",
+        "title": "Book Hhh",
+        "publishYear": "2021",
+        "pageCount": 800
+      },
+      {
+        "author": "Iii Iii",
+        "title": "Book Iii",
+        "publishYear": "2012",
+        "pageCount": 600
+      }
+    ]
+  },
+  {
+    "name": "Eee",
+    "surname": "Fff",
+    "books": [
+      {
+        "author": "Aaa Aaa",
+        "title": "Book Aaa",
+        "publishYear": "2027",
+        "pageCount": 500
+      },
+      {
+        "author": "Bbb Bbb",
+        "title": "Book Bbb",
+        "publishYear": "2018",
+        "pageCount": 200
+      },
+      {
+        "author": "Jjj Jjj",
+        "title": "Book Jjj",
+        "publishYear": "2001",
+        "pageCount": 1000
+      },
+      {
+        "author": "Kkk Kkk",
+        "title": "Book Kkk",
+        "publishYear": "1995",
+        "pageCount": 700
+      },
+      {
+        "author": "Lll Lll",
+        "title": "Book Lll",
+        "publishYear": "2025",
+        "pageCount": 1100
+      }
+    ]
+  }
+]