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 +1,27 @@
+import java.util.Objects;
+
+final class ImmutableClass {
+  ImmutableClass(MutableClass firstField, String secondField, Integer thirdField) {
+    this.firstField = new MutableClass(Objects.requireNonNull(firstField));
+    this.secondField = secondField;
+    this.thirdField = thirdField;
+  }
+
+  public MutableClass getFirstField() {
+    return new MutableClass(firstField);
+  }
+
+  public String getSecondField() {
+    // Копировать не нужно так как String является Immutable
+    return secondField;
+  }
+
+  public Integer getThirdField() {
+    // Копировать не нужно так как Integer является Immutable
+    return thirdField;
+  }
+
+  private final MutableClass firstField;
+  private final String secondField;
+  private final Integer thirdField;
+}
@@ -0,0 +1,20 @@
+class MutableClass {
+  MutableClass(int value) {
+    this.setValue(value);
+  }
+
+  // Конструктор копирования
+  public MutableClass(MutableClass other) {
+    this.value = other.value;
+  }
+
+  public int getValue() {
+    return value;
+  }
+
+  public void setValue(int value) {
+    this.value = value;
+  }
+
+  private int value;
+}
@@ -0,0 +1,9 @@
+# Homework 01
+
+Реализовать свой иммутабельный класс, который будет
+внутри себя содержать поле с изменяемым классом.
+
+## UPDATED
+
+Иммутабельный класс должен содержать минимум 3 различных поля, включая поле с
+изменяемым классом.
@@ -0,0 +1,61 @@
+# Emacs/vim
+
+*~
+*.swp
+
+# VSCode
+
+.vscode
+.classpath
+.project
+.settings/
+
+
+# MacOS
+
+.DS_Store
+
+# CS56 specific: Secrets files
+
+localhost.json
+heroku.json
+
+# Maven (from: https://github.com/github/gitignore/blob/master/Maven.gitignore)
+
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+# https://github.com/takari/maven-wrapper#usage-without-binary-jar
+.mvn/wrapper/maven-wrapper.jar
+
+# Java (from: https://github.com/github/gitignore/blob/master/Java.gitignore)
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
@@ -0,0 +1,29 @@
+# Homework 02
+
+1. Создать класс Student, обязательное поле класса Student - List<Book> (минимум по 5 книг у каждого)
+
+2. Создать текстовый файл со студентами и книгами
+
+3. При помощи внутренних фреймворков и библиотек для ввода-вывода информации в Java считать содержимое файла и заполнить List<Student> этими данными (Должен быть реализован механизм заполнения коллекции студентов из текстового файла)
+
+4. При помощи одного (не допускается объявления никаких промежуточных переменных, совсем никаких) стрима:
+
+    Вывести в консоль каждого студента (переопределите toString)
+
+    Получить для каждого студента список книг
+
+    Получить книги
+
+    Отсортировать книги по количеству страниц (Не забывайте про условия для сравнения объектов)
+
+    Оставить только уникальные книги
+
+    Отфильтровать книги, оставив только те, которые были выпущены после 2000 года
+
+    Ограничить стрим на 3 элементах
+
+    Получить из книг годы выпуска
+
+    При помощи методов короткого замыкания (почитайте самостоятельно что это такое) вернуть Optional от года
+
+    При помощи методов получения значения из Optional вывести в консоль год выпуска найденной книги, либо запись о том, что такая книга отсутствует
@@ -0,0 +1 @@
+xargs img2pdf -o result.pdf < order.txt
@@ -0,0 +1,10 @@
+Book{author='Ggg Ggg', title='Book Ggg', publishYear=2005, pageCount=100}
+Book{author='Bbb Bbb', title='Book Bbb', publishYear=2018, pageCount=200}
+Book{author='Ddd Ddd', title='Book Ddd', publishYear=2015, pageCount=400}
+Book{author='Aaa Aaa', title='Book Aaa', publishYear=2027, pageCount=500}
+Book{author='Iii Iii', title='Book Iii', publishYear=2012, pageCount=600}
+Book{author='Hhh Hhh', title='Book Hhh', publishYear=2021, pageCount=800}
+Book{author='Ccc Ccc', title='Book Ccc', publishYear=2024, pageCount=900}
+Book{author='Jjj Jjj', title='Book Jjj', publishYear=2001, pageCount=1000}
+Book{author='Lll Lll', title='Book Lll', publishYear=2025, pageCount=1100}
+Book{author='Fff Fff', title='Book Fff', publishYear=2030, pageCount=1200}
@@ -0,0 +1,48 @@
+❮ mvn exec:java -Dexec.mainClass="com.example.App" > output.txt
+
+[INFO] Scanning for projects...
+[INFO] 
+[INFO] ---------------------< com.example:student-reader >---------------------
+[INFO] Building student-reader 1.0-SNAPSHOT
+[INFO]   from pom.xml
+[INFO] --------------------------------[ jar ]---------------------------------
+[INFO] 
+[INFO] --- exec:3.6.3:java (default-cli) @ student-reader ---
+Student{
+  name='Aaa'
+  surname='Bbb'
+  books=
+    Book{author='Aaa Aaa', title='Book Aaa', publishYear=2027, pageCount=500}
+    Book{author='Bbb Bbb', title='Book Bbb', publishYear=2018, pageCount=200}
+    Book{author='Ccc Ccc', title='Book Ccc', publishYear=2024, pageCount=900}
+    Book{author='Ddd Ddd', title='Book Ddd', publishYear=2015, pageCount=400}
+    Book{author='Ddd Ddd', title='Book Ddd', publishYear=2015, pageCount=400}
+}
+Student{
+  name='Ccc'
+  surname='Ddd'
+  books=
+    Book{author='Eee Eee', title='Book Eee', publishYear=1999, pageCount=300}
+    Book{author='Fff Fff', title='Book Fff', publishYear=2030, pageCount=1200}
+    Book{author='Ggg Ggg', title='Book Ggg', publishYear=2005, pageCount=100}
+    Book{author='Hhh Hhh', title='Book Hhh', publishYear=2021, pageCount=800}
+    Book{author='Iii Iii', title='Book Iii', publishYear=2012, pageCount=600}
+}
+Student{
+  name='Eee'
+  surname='Fff'
+  books=
+    Book{author='Aaa Aaa', title='Book Aaa', publishYear=2027, pageCount=500}
+    Book{author='Bbb Bbb', title='Book Bbb', publishYear=2018, pageCount=200}
+    Book{author='Jjj Jjj', title='Book Jjj', publishYear=2001, pageCount=1000}
+    Book{author='Kkk Kkk', title='Book Kkk', publishYear=1995, pageCount=700}
+    Book{author='Lll Lll', title='Book Lll', publishYear=2025, pageCount=1100}
+}
+Год выпуска: 2005
+Выполнение программы завершено
+[INFO] ------------------------------------------------------------------------
+[INFO] BUILD SUCCESS
+[INFO] ------------------------------------------------------------------------
+[INFO] Total time:  1.025 s
+[INFO] Finished at: 2026-08-06T23:30:03+04:00
+[INFO] ------------------------------------------------------------------------
@@ -0,0 +1,7 @@
+"screenshots/Screenshot from 2026-08-06 23-28-36.png"
+"screenshots/Screenshot from 2026-08-06 23-29-11.png"
+"screenshots/Screenshot from 2026-08-06 23-29-31.png"
+"screenshots/Screenshot from 2026-08-06 23-52-39.png"
+"screenshots/Screenshot from 2026-08-06 23-35-03.png"
+"screenshots/Screenshot from 2026-08-06 23-26-45.png"
+"screenshots/Screenshot from 2026-08-06 23-31-03.png"
@@ -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
+      }
+    ]
+  }
+]
@@ -0,0 +1,147 @@
+# =========================
+# Gradle
+# =========================
+
+.gradle/
+.gradle-tasknamecache
+gradle-app.setting
+
+# Build directories
+bin/
+**/bin/
+out/
+**/out/
+build/
+**/build/
+target/
+**/target/
+
+# Keep Gradle Wrapper files
+.gradle/wrapper/
+!gradle/wrapper/gradle-wrapper.jar
+!gradle/wrapper/gradle-wrapper.properties
+
+# =========================
+# Java
+# =========================
+
+# Compiled class files
+*.class
+
+# Java package files
+*.jar
+*.war
+*.ear
+
+# Java temporary files
+*.ctxt
+*.mtj.tmp/
+
+# JVM crash logs
+hs_err_pid*
+
+
+# =========================
+# IntelliJ IDEA
+# =========================
+
+.idea/
+*.iws
+*.iml
+
+# IDEA generated files
+*.idea/dataSources.ids
+*.idea/dataSources.local.xml
+*.idea/dataSources.xml
+*.idea/dictionaries/
+*.idea/dynamic.xml
+*.idea/gradle.xml
+*.idea/jsLibraryMappings.xml
+*.idea/libraries/
+*.idea/mongoSettings.xml
+*.idea/sqlDataSources.xml
+*.idea/tasks.xml
+*.idea/uiDesigner.xml
+*.idea/vcs.xml
+*.idea/workspace.xml
+*.idea_modules/
+
+
+# =========================
+# Eclipse / VS Code
+# =========================
+
+.classpath
+.project
+.settings/
+
+.vscode/
+
+
+# =========================
+# OS generated files
+# =========================
+
+# macOS
+.DS_Store
+.AppleDB
+.AppleDesktop
+.AppleDouble
+.DocumentRevisions-V100
+.LSOverride
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+._*
+.apdisk
+
+# Windows
+Thumbs.db
+ehthumbs.db
+Desktop.ini
+
+
+# =========================
+# IDE / Plugin generated files
+# =========================
+
+Icon
+Network Trash Folder
+Temporary Items
+
+atlassian-ide-plugin.xml
+
+
+# =========================
+# Crashlytics / Fabric
+# =========================
+
+com_crashlytics_export_strings.xml
+crashlytics-build.properties
+crashlytics.properties
+fabric.properties
+
+
+# =========================
+# Temporary files
+# =========================
+
+*~
+*.swp
+*.swo
+*.tmp
+
+
+# =========================
+# Build artifacts
+# =========================
+
+dependency-reduced-pom.xml
+release.properties
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+
+buildNumber.properties
@@ -0,0 +1,3 @@
+# Homework 03
+
+Реализовать паттерны: Стратегия, Цепочка обязанностей, Билдер, Прокси, Декоратор, Адаптер
@@ -0,0 +1,21 @@
+❮ ./gradlew run > output.txt
+
+Reusing configuration cache.
+> Task :app:processResources NO-SOURCE
+> Task :app:compileJava UP-TO-DATE
+> Task :app:classes UP-TO-DATE
+
+> Task :app:run
+Был передан аргумент -568655464
+Product{first='first', second='second', third=3}
+ConcreteHandlerA обработал int: 42
+ConcreteHandlerB обработал String: Hello
+ConcreteComponent выполняет операцию
+ConcreteDecorator добавляет поведение
+ServiceProxy разрешает выполнение операции
+ConcreteService выполняет операцию
+ConcreteStrategyB выполняет операцию
+
+BUILD SUCCESSFUL in 837ms
+2 actionable tasks: 1 executed, 1 up-to-date
+Configuration cache entry reused.
@@ -0,0 +1,8 @@
+"screenshots/Screenshot from 2026-08-08 19-09-49.png"
+"screenshots/Screenshot from 2026-08-08 19-19-23.png"
+"screenshots/Screenshot from 2026-08-08 19-21-54.png"
+"screenshots/Screenshot from 2026-08-08 19-58-26.png"
+"screenshots/Screenshot from 2026-08-08 19-59-37.png"
+"screenshots/Screenshot from 2026-08-08 20-01-08.png"
+"screenshots/Screenshot from 2026-08-08 20-02-37.png"
+"screenshots/Screenshot from 2026-08-08 20-11-19.png"
@@ -0,0 +1,40 @@
+#!/usr/bin/env fish
+
+set BASE app/src/main/java/org/example
+
+# Создание директорий
+mkdir -p $BASE/{strategy,chain,builder,proxy,decorator,adapter}
+
+# Strategy
+touch $BASE/strategy/Strategy.java
+touch $BASE/strategy/ConcreteStrategyA.java
+touch $BASE/strategy/ConcreteStrategyB.java
+touch $BASE/strategy/Context.java
+
+# Chain of Responsibility
+touch $BASE/chain/Handler.java
+touch $BASE/chain/AbstractHandler.java
+touch $BASE/chain/ConcreteHandlerA.java
+touch $BASE/chain/ConcreteHandlerB.java
+
+# Builder
+touch $BASE/builder/Product.java
+touch $BASE/builder/ProductBuilder.java
+
+# Proxy
+touch $BASE/proxy/Service.java
+touch $BASE/proxy/RealService.java
+touch $BASE/proxy/ServiceProxy.java
+
+# Decorator
+touch $BASE/decorator/Component.java
+touch $BASE/decorator/ConcreteComponent.java
+touch $BASE/decorator/Decorator.java
+touch $BASE/decorator/ConcreteDecorator.java
+
+# Adapter
+touch $BASE/adapter/Target.java
+touch $BASE/adapter/Adaptee.java
+touch $BASE/adapter/Adapter.java
+
+echo "Java pattern files created successfully!"
@@ -0,0 +1,12 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+
+# Binary files should be left untouched
+*.jar           binary
+
@@ -0,0 +1,44 @@
+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * This generated file contains a sample Java application project to get you started.
+ * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/9.6.1/userguide/building_java_projects.html in the Gradle documentation.
+ * This project uses @Incubating APIs which are subject to change.
+ */
+
+plugins {
+    // Apply the application plugin to add support for building a CLI application in Java.
+    application
+}
+
+repositories {
+    // Use Maven Central for resolving dependencies.
+    mavenCentral()
+}
+
+dependencies {
+    // This dependency is used by the application.
+    implementation(libs.guava)
+}
+
+testing {
+    suites {
+        // Configure the built-in test suite
+        val test = named<JvmTestSuite>("test") {
+            // Use JUnit Jupiter test framework
+            useJUnitJupiter("6.0.1")
+        }
+    }
+}
+
+// Apply a specific Java toolchain to ease working on different environments.
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+application {
+    // Define the main class for the application.
+    mainClass = "org.example.App"
+}
@@ -0,0 +1,79 @@
+/*
+ * This source file was generated by the Gradle 'init' task
+ */
+package org.example;
+
+import org.example.adapter.*;
+import org.example.builder.*;
+import org.example.chain.*;
+import org.example.decorator.*;
+import org.example.proxy.*;
+import org.example.strategy.*;
+
+public class App {
+  public static void main(String[] args) {
+    run();
+  }
+
+  private static void run() {
+    checkAdapterPattern();
+
+    checkBuilderPattern();
+
+    checkChainPattern();
+
+    checkDecoratorPattern();
+
+    checkProxyPattern();
+
+    checkStrategyPattern();
+  }
+
+  private static void checkAdapterPattern() {
+    Adaptee adaptee = new Adaptee();
+    Target target = new Adapter(adaptee);
+
+    target.methodWithoutArguments();
+  }
+
+  private static void checkBuilderPattern() {
+    Product product =
+        new ProductBuilder().setFirst("first").setSecond("second").setThird(3).build();
+
+    System.out.println(product);
+  }
+
+  private static void checkChainPattern() {
+    Handler handler = new ConcreteHandlerA();
+    handler.setNext(new ConcreteHandlerB());
+
+    handler.handle(42);
+    handler.handle("Hello");
+  }
+
+  private static void checkDecoratorPattern() {
+    Component component = new ConcreteComponent();
+    Component decorator = new ConcreteDecorator(component);
+
+    decorator.operation();
+  }
+
+  private static void checkProxyPattern() {
+    Service service = new ConcreteService();
+    Service proxy = new ServiceProxy(service);
+
+    proxy.execute();
+  }
+
+  private static void checkStrategyPattern() {
+    Context context = new Context(new ConcreteStrategyA());
+
+    boolean crayfishWhistled = true; // Если рак на горе свистнул
+
+    if (crayfishWhistled) {
+      context.setStrategy(new ConcreteStrategyB());
+    }
+
+    context.executeStrategy();
+  }
+}
@@ -0,0 +1,9 @@
+package org.example.adapter;
+
+/** Adaptee */
+public class Adaptee {
+
+  public void methodWithArgument(int argument) {
+    System.out.println("Был передан аргумент " + argument);
+  }
+}
@@ -0,0 +1,21 @@
+package org.example.adapter;
+
+import java.util.Random;
+
+/** Adapter */
+public class Adapter implements Target {
+
+  public Adapter(Adaptee adaptee) {
+    this.adaptee = adaptee;
+    this.random = new Random();
+  }
+
+  @Override
+  public void methodWithoutArguments() {
+    int argument = random.nextInt();
+    adaptee.methodWithArgument(argument);
+  }
+
+  private final Adaptee adaptee;
+  private Random random;
+}
@@ -0,0 +1,7 @@
+package org.example.adapter;
+
+/** Target */
+public interface Target {
+
+  void methodWithoutArguments();
+}
@@ -0,0 +1,41 @@
+package org.example.builder;
+
+/** Product */
+public class Product {
+
+  public Product(String first, String second, int third) {
+    this.first = first;
+    this.second = second;
+    this.third = third;
+  }
+
+  public String getFirst() {
+    return first;
+  }
+
+  public String getSecond() {
+    return second;
+  }
+
+  public int getThird() {
+    return third;
+  }
+
+  @Override
+  public String toString() {
+    return "Product{"
+        + "first='"
+        + first
+        + '\''
+        + ", second='"
+        + second
+        + '\''
+        + ", third="
+        + third
+        + '}';
+  }
+
+  private final String first;
+  private final String second;
+  private final int third;
+}
@@ -0,0 +1,28 @@
+package org.example.builder;
+
+/** Builder */
+public class ProductBuilder {
+
+  public ProductBuilder setFirst(String first) {
+    this.first = first;
+    return this;
+  }
+
+  public ProductBuilder setSecond(String second) {
+    this.second = second;
+    return this;
+  }
+
+  public ProductBuilder setThird(int third) {
+    this.third = third;
+    return this;
+  }
+
+  public Product build() {
+    return new Product(first, second, third);
+  }
+
+  private String first;
+  private String second;
+  private int third;
+}
@@ -0,0 +1,18 @@
+package org.example.chain;
+
+/** Abstract Handler */
+public abstract class AbstractHandler implements Handler {
+
+  @Override
+  public void setNext(Handler handler) {
+    this.next = handler;
+  }
+
+  protected void handleNext(Object request) {
+    if (next != null) {
+      next.handle(request);
+    }
+  }
+
+  private Handler next;
+}
@@ -0,0 +1,14 @@
+package org.example.chain;
+
+/** Concrete Handler A */
+public class ConcreteHandlerA extends AbstractHandler {
+
+  @Override
+  public void handle(Object request) {
+    if (request instanceof Integer) {
+      System.out.println("ConcreteHandlerA обработал int: " + request);
+    } else {
+      handleNext(request);
+    }
+  }
+}
@@ -0,0 +1,14 @@
+package org.example.chain;
+
+/** Concrete Handler B */
+public class ConcreteHandlerB extends AbstractHandler {
+
+  @Override
+  public void handle(Object request) {
+    if (request instanceof String) {
+      System.out.println("ConcreteHandlerB обработал String: " + request);
+    } else {
+      handleNext(request);
+    }
+  }
+}
@@ -0,0 +1,8 @@
+package org.example.chain;
+
+/** Handler */
+public interface Handler {
+  void setNext(Handler handler);
+
+  void handle(Object request);
+}
@@ -0,0 +1,6 @@
+package org.example.decorator;
+
+/** Component */
+public interface Component {
+  void operation();
+}
@@ -0,0 +1,10 @@
+package org.example.decorator;
+
+/** Concrete Component */
+public class ConcreteComponent implements Component {
+
+  @Override
+  public void operation() {
+    System.out.println("ConcreteComponent выполняет операцию");
+  }
+}
@@ -0,0 +1,15 @@
+package org.example.decorator;
+
+/** Concrete Decorator */
+public class ConcreteDecorator extends Decorator {
+
+  public ConcreteDecorator(Component component) {
+    super(component);
+  }
+
+  @Override
+  public void operation() {
+    component.operation();
+    System.out.println("ConcreteDecorator добавляет поведение");
+  }
+}
@@ -0,0 +1,16 @@
+package org.example.decorator;
+
+/** Decorator */
+public abstract class Decorator implements Component {
+
+  protected Decorator(Component component) {
+    this.component = component;
+  }
+
+  @Override
+  public void operation() {
+    component.operation();
+  }
+
+  protected final Component component;
+}
@@ -0,0 +1,10 @@
+package org.example.proxy;
+
+/** Concrete Service */
+public class ConcreteService implements Service {
+
+  @Override
+  public void execute() {
+    System.out.println("ConcreteService выполняет операцию");
+  }
+}
@@ -0,0 +1,6 @@
+package org.example.proxy;
+
+/** Service */
+public interface Service {
+  void execute();
+}
@@ -0,0 +1,17 @@
+package org.example.proxy;
+
+/** Service Proxy */
+public class ServiceProxy implements Service {
+
+  public ServiceProxy(Service service) {
+    this.service = service;
+  }
+
+  @Override
+  public void execute() {
+    System.out.println("ServiceProxy разрешает выполнение операции");
+    service.execute();
+  }
+
+  private final Service service;
+}
@@ -0,0 +1,10 @@
+package org.example.strategy;
+
+/** Concrete Strategy A */
+public class ConcreteStrategyA implements Strategy {
+
+  @Override
+  public void execute() {
+    System.out.println("ConcreteStrategyA выполняет операцию");
+  }
+}
@@ -0,0 +1,10 @@
+package org.example.strategy;
+
+/** Concrete Strategy B */
+public class ConcreteStrategyB implements Strategy {
+
+  @Override
+  public void execute() {
+    System.out.println("ConcreteStrategyB выполняет операцию");
+  }
+}
@@ -0,0 +1,19 @@
+package org.example.strategy;
+
+/** Context */
+public class Context {
+
+  public Context(Strategy strategy) {
+    this.strategy = strategy;
+  }
+
+  public void setStrategy(Strategy strategy) {
+    this.strategy = strategy;
+  }
+
+  public void executeStrategy() {
+    strategy.execute();
+  }
+
+  private Strategy strategy;
+}
@@ -0,0 +1,6 @@
+package org.example.strategy;
+
+/** Strategy */
+public interface Strategy {
+  void execute();
+}
@@ -0,0 +1,7 @@
+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/build_environment.html#sec:gradle_configuration_properties
+
+org.gradle.configuration-cache=true
+org.gradle.parallel=true
+org.gradle.caching=true
+
@@ -0,0 +1,8 @@
+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/version_catalogs.html#sec::toml-dependencies-format
+
+[versions]
+guava = "33.5.0-jre"
+
+[libraries]
+guava = { module = "com.google.guava:guava", version.ref = "guava" }
@@ -0,0 +1,9 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.6.1-bin.zip
+networkTimeout=10000
+retries=0
+retryBackOffMs=500
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   gradlew start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh gradlew
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/<unknown>/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
@@ -0,0 +1,82 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  gradlew startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables, and ensure extensions are enabled
+setlocal EnableExtensions
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute gradlew
+@rem endlocal doesn't take effect until after the line is parsed and variables are expanded
+@rem which allows us to clear the local environment before executing the java command
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
+
+:exitWithErrorLevel
+@rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
+"%COMSPEC%" /c exit %ERRORLEVEL%
@@ -0,0 +1,15 @@
+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * The settings file is used to specify which projects to include in your build.
+ * For more detailed information on multi-project builds, please refer to https://docs.gradle.org/9.6.1/userguide/multi_project_builds.html in the Gradle documentation.
+ * This project uses @Incubating APIs which are subject to change.
+ */
+
+plugins {
+    // Apply the foojay-resolver plugin to allow automatic download of JDKs
+    id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
+}
+
+rootProject.name = "project-root"
+include("app")
@@ -0,0 +1,61 @@
+# Emacs/vim
+
+*~
+*.swp
+
+# VSCode
+
+.vscode
+.classpath
+.project
+.settings/
+
+
+# MacOS
+
+.DS_Store
+
+# CS56 specific: Secrets files
+
+localhost.json
+heroku.json
+
+# Maven (from: https://github.com/github/gitignore/blob/master/Maven.gitignore)
+
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+# https://github.com/takari/maven-wrapper#usage-without-binary-jar
+.mvn/wrapper/maven-wrapper.jar
+
+# Java (from: https://github.com/github/gitignore/blob/master/Java.gitignore)
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
@@ -0,0 +1,18 @@
+<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>concurrency</artifactId>
+  <packaging>jar</packaging>
+  <version>1.0-SNAPSHOT</version>
+  <name>concurrency</name>
+  <url>http://maven.apache.org</url>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>
@@ -0,0 +1,47 @@
+package com.example;
+
+import com.example.util.ThreadUtils;
+
+public class DeadLock {
+
+  private static final Object LOCK_A = new Object();
+  private static final Object LOCK_B = new Object();
+
+  public static void main(String[] args) {
+
+    Thread thread1 =
+        new Thread(
+            () -> {
+              synchronized (LOCK_A) {
+                System.out.println("Thread 1: получил LOCK_A");
+
+                ThreadUtils.sleep(100);
+
+                System.out.println("Thread 1: пытается получить LOCK_B");
+
+                synchronized (LOCK_B) {
+                  System.out.println("Thread 1: получил LOCK_B");
+                }
+              }
+            });
+
+    Thread thread2 =
+        new Thread(
+            () -> {
+              synchronized (LOCK_B) {
+                System.out.println("Thread 2: получил LOCK_B");
+
+                ThreadUtils.sleep(100);
+
+                System.out.println("Thread 2: пытается получить LOCK_A");
+
+                synchronized (LOCK_A) {
+                  System.out.println("Thread 2: получил LOCK_A");
+                }
+              }
+            });
+
+    thread1.start();
+    thread2.start();
+  }
+}
@@ -0,0 +1,106 @@
+package com.example;
+
+public class LiveLock {
+
+  static class Corridor {
+    private Person currentPerson;
+
+    public Corridor(Person person) {
+      currentPerson = person;
+    }
+
+    public synchronized void setPerson(Person person) {
+      currentPerson = person;
+    }
+
+    public synchronized Person getPerson() {
+      return currentPerson;
+    }
+
+    public synchronized void pass() {
+      System.out.printf("%s прошёл по коридору!%n", currentPerson.name);
+    }
+  }
+
+  static class Person {
+    private final String name;
+    private volatile boolean wantsToPass;
+
+    public Person(String personName) {
+      name = personName;
+      wantsToPass = true;
+    }
+
+    public String getName() {
+      return name;
+    }
+
+    public boolean wantsToPass() {
+      return wantsToPass;
+    }
+
+    public void walkThrough(Corridor corridor, Person otherPerson) {
+      while (wantsToPass) {
+
+        // Если сейчас право пройти принадлежит другому человеку,
+        // немного ждём и снова проверяем ситуацию.
+        if (corridor.getPerson() != this) {
+          try {
+            Thread.sleep(1);
+          } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            return;
+          }
+          continue;
+        }
+
+        // Если второй человек тоже хочет пройти,
+        // вежливо уступаем ему дорогу.
+        if (otherPerson.wantsToPass()) {
+          System.out.printf("%s: Проходи первым, %s!%n", name, otherPerson.getName());
+
+          corridor.setPerson(otherPerson);
+          continue;
+        }
+
+        // Если другой человек уже прошёл,
+        // наконец сами идём по коридору.
+        corridor.pass();
+        wantsToPass = false;
+
+        System.out.printf("%s: Спасибо, %s!%n", name, otherPerson.getName());
+
+        corridor.setPerson(otherPerson);
+      }
+    }
+  }
+
+  public static void main(String[] args) {
+
+    final Person ivan = new Person("Иван");
+    final Person petr = new Person("Пётр");
+
+    // Изначально право пройти по коридору принадлежит Ивану.
+    final Corridor corridor = new Corridor(ivan);
+
+    // Первый поток — Иван.
+    new Thread(
+            new Runnable() {
+              @Override
+              public void run() {
+                ivan.walkThrough(corridor, petr);
+              }
+            })
+        .start();
+
+    // Второй поток — Пётр.
+    new Thread(
+            new Runnable() {
+              @Override
+              public void run() {
+                petr.walkThrough(corridor, ivan);
+              }
+            })
+        .start();
+  }
+}
@@ -0,0 +1,12 @@
+package com.example.util;
+
+public class ThreadUtils {
+
+  public static void sleep(long millis) {
+    try {
+      Thread.sleep(millis);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+    }
+  }
+}
@@ -0,0 +1,55 @@
+package com.example;
+
+public class TwoThreads {
+
+  private static final Object lock = new Object();
+  private static boolean turnOne = true;
+
+  public static void main(String[] args) {
+
+    Thread thread1 =
+        new Thread(
+            () -> {
+              while (true) {
+                synchronized (lock) {
+                  while (!turnOne) {
+                    try {
+                      lock.wait();
+                    } catch (InterruptedException e) {
+                      Thread.currentThread().interrupt();
+                      return;
+                    }
+                  }
+
+                  System.out.print("1");
+                  turnOne = false;
+                  lock.notifyAll();
+                }
+              }
+            });
+
+    Thread thread2 =
+        new Thread(
+            () -> {
+              while (true) {
+                synchronized (lock) {
+                  while (turnOne) {
+                    try {
+                      lock.wait();
+                    } catch (InterruptedException e) {
+                      Thread.currentThread().interrupt();
+                      return;
+                    }
+                  }
+
+                  System.out.print("2");
+                  turnOne = true;
+                  lock.notifyAll();
+                }
+              }
+            });
+
+    thread1.start();
+    thread2.start();
+  }
+}