Hw2

src/main/java/edu/hw2/Main.java

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+package edu.hw2;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public final class Main {
+    private final static Logger LOGGER = LogManager.getLogger();
+
+    private Main() {
+    }
+
+    public static void main(String[] args) {
+    }
+}

src/main/java/edu/hw2/Task1/Expr.java

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+package edu.hw2.Task1;
+
+public sealed interface Expr {
+    double evaluate();
+
+    record Constant(double value) implements Expr {
+        @Override
+        public double evaluate() {
+            return value;
+        }
+    }
+
+    public record Negate(Expr value) implements Expr {
+        @Override
+        public double evaluate() {
+            return value.evaluate() * -1;
+        }
+    }
+
+    record Exponent(Expr value, double exponent) implements Expr {
+        @Override
+        public double evaluate() {
+            return Math.pow(value.evaluate(), exponent);
+        }
+    }
+
+    record Addition(Expr value1, Expr value2) implements Expr {
+        @Override
+        public double evaluate() {
+            return value1.evaluate() + value2.evaluate();
+        }
+    }
+
+    record Multiplication(Expr value1, Expr value2) implements Expr {
+        @Override
+        public double evaluate() {
+            return value1.evaluate() * value2.evaluate();
+        }
+    }
+}

src/main/java/edu/hw2/Task2/Rectangle.java

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+package edu.hw2.Task2;
+
+public class Rectangle {
+    private int width;
+    private int height;
+
+    public Rectangle(int width, int height) {
+        this.width = width;
+        this.height = height;
+    }
+
+    public Rectangle setWidth(int width) {
+        return new Rectangle(width, height);
+    }
+
+    public Rectangle setHeight(int height) {
+        return new Rectangle(width, height);
+    }
+
+    public double area() {
+        return width * height;
+    }
+}

src/main/java/edu/hw2/Task2/Square.java

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+package edu.hw2.Task2;
+
+public class Square extends Rectangle {
+    public Square(int sideLength) {
+        super(sideLength, sideLength);
+    }
+
+    @Override
+    public Rectangle setWidth(int width) {
+        return new Square(width);
+    }
+
+    @Override
+    public Rectangle setHeight(int height) {
+        return new Square(height);
+    }
+}

src/main/java/edu/hw2/Task3/Connection/Connection.java

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+package edu.hw2.Task3.Connection;
+
+public interface Connection extends AutoCloseable {
+    double PROBABLITY_BOUND = 0.5;
+
+    void execute(String command);
+
+    default boolean isConnectionFailed() {
+        return Math.random() > PROBABLITY_BOUND;
+    }
+}

src/main/java/edu/hw2/Task3/Connection/FaultyConnection.java

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+package edu.hw2.Task3.Connection;
+
+import edu.hw2.Task3.ConnectionException;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class FaultyConnection implements Connection {
+    private final static Logger LOGGER = LogManager.getLogger();
+
+    @Override
+    public void execute(String command) {
+        if (isConnectionFailed()) {
+            throw new ConnectionException("Connection cannot be established", new Exception());
+        }
+        LOGGER.info(command);
+    }
+
+    @Override
+    public void close() {
+        LOGGER.info("Connection closed");
+    }
+}

src/main/java/edu/hw2/Task3/Connection/StableConnection.java

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+package edu.hw2.Task3.Connection;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class StableConnection implements Connection {
+    private final static Logger LOGGER = LogManager.getLogger();
+
+    @Override
+    public void execute(String command) {
+        LOGGER.info(command);
+    }
+
+    @Override
+    public void close() {
+        LOGGER.info("Connection closed!");
+    }
+}

src/main/java/edu/hw2/Task3/ConnectionException.java

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+package edu.hw2.Task3;
+
+public class ConnectionException extends RuntimeException {
+    public ConnectionException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/edu/hw2/Task3/ConnectionManager/ConnectionManager.java

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+package edu.hw2.Task3.ConnectionManager;
+
+import edu.hw2.Task3.Connection.Connection;
+
+public interface ConnectionManager {
+    double PROBABLITY_BOUND = 0.5;
+
+    Connection getConnection();
+
+    default boolean isFaultyConnection() {
+        return Math.random() > PROBABLITY_BOUND;
+    }
+}

src/main/java/edu/hw2/Task3/ConnectionManager/DefaultConnectionManager.java

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+package edu.hw2.Task3.ConnectionManager;
+
+import edu.hw2.Task3.Connection.Connection;
+import edu.hw2.Task3.Connection.FaultyConnection;
+import edu.hw2.Task3.Connection.StableConnection;
+
+public class DefaultConnectionManager implements ConnectionManager {
+    @Override
+    public Connection getConnection() {
+        if (isFaultyConnection()) {
+            return new FaultyConnection();
+        }
+        return new StableConnection();
+    }
+}

src/main/java/edu/hw2/Task3/ConnectionManager/FaultyConnectionManager.java

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+package edu.hw2.Task3.ConnectionManager;
+
+import edu.hw2.Task3.Connection.Connection;
+import edu.hw2.Task3.Connection.FaultyConnection;
+
+public class FaultyConnectionManager implements ConnectionManager {
+    @Override
+    public Connection getConnection() {
+        return new FaultyConnection();
+    }
+}

src/main/java/edu/hw2/Task3/PopularCommandExecutor.java

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+package edu.hw2.Task3;
+
+import edu.hw2.Task3.Connection.Connection;
+import edu.hw2.Task3.ConnectionManager.ConnectionManager;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public final class PopularCommandExecutor {
+    private final ConnectionManager manager;
+    private final int maxAttemps;
+    private final static Logger LOGGER = LogManager.getLogger();
+
+    public PopularCommandExecutor(ConnectionManager manager, int maxAttemps) {
+        this.manager = manager;
+        this.maxAttemps = maxAttemps;
+    }
+
+    public void updatePackages() {
+        tryExecute("apt update && apt upgrade -y");
+    }
+
+    private void tryExecute(String command) {
+        int attemps = 0;
+        while (attemps < maxAttemps) {
+            Connection connection = manager.getConnection();
+            try {
+                connection.execute(command);
+            } catch (ConnectionException e) {
+                if (attemps == maxAttemps - 1) {
+                    LOGGER.info(e.getMessage());
+                }
+                attemps++;
+            } finally {
+                try {
+                    connection.close();
+                } catch (Exception closeException) {
+                    LOGGER.info(connection.toString() + " didnt close!");
+                }
+            }
+        }
+    }
+}

src/main/java/edu/hw2/Task4/Call.java

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+package edu.hw2.Task4;
+
+public class Call {
+    private Call() {
+    }
+
+    public static CallingInfo callingInfo() {
+        var stackTrace = new Throwable().getStackTrace();
+        int stackLength = stackTrace.length;
+        String callerMethodName = stackTrace[1].getMethodName();
+        String callerClassName = stackTrace[1].getClassName();
+        return new CallingInfo(callerClassName, callerMethodName);
+    }
+}

src/main/java/edu/hw2/Task4/CallingInfo.java

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+package edu.hw2.Task4;
+
+public record CallingInfo(String className, String methodName) {
+}

src/test/java/edu/hw2/CallingInfoTest.java

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+package edu.hw2;
+
+import edu.hw2.Task4.Call;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+public class CallingInfoTest {
+    @Test
+    @DisplayName("Вызов метода из CallingInfoTest")
+    public void callingInfo_ShouldReturnThisClassAndMethodName() {
+        var info = Call.callingInfo();
+
+        String className = this.getClass().getName();
+        String methodName = new Object() {}
+            .getClass()
+            .getEnclosingMethod()
+            .getName();
+
+        assertThat(info.className()).isEqualTo(className);
+        assertThat(info.methodName()).isEqualTo(methodName);
+    }
+}

src/test/java/edu/hw2/ExprTest.java

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+package edu.hw2;
+
+import edu.hw2.Task1.Expr;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+public class ExprTest {
+    @Test
+    @DisplayName("Базовый тест")
+    void expr_shouldCorrectlyEvaluate_basicTest() {
+        var two = new Expr.Constant(2);
+        var four = new Expr.Constant(4);
+        var negOne = new Expr.Negate(new Expr.Constant(1));
+        var sumTwoFour = new Expr.Addition(two, four);
+        var mult = new Expr.Multiplication(sumTwoFour, negOne);
+        var exp = new Expr.Exponent(mult, 2);
+        var res = new Expr.Addition(exp, new Expr.Constant(1));
+
+        assertThat(res.evaluate()).isEqualTo(37.0);
+    }
+
+    @Test
+    @DisplayName("Отрицательное число в Negate")
+    void expr_shouldEvaluateMinusOne_whenValueAlreadyNagative() {
+        var negOne = new Expr.Negate(new Expr.Constant(-1));
+
+        assertThat(negOne.evaluate()).isEqualTo(1);
+    }
+
+    @Test
+    @DisplayName("Отрицательные числа в Exponent")
+    void expr_shouldExponentCorrectly_whenValueAndExponentNegative() {
+        var negOne = new Expr.Exponent(new Expr.Constant(-2), -5);
+
+        assertThat(negOne.evaluate()).isEqualTo(-0.03125);
+    }
+}

src/test/java/edu/hw2/RectangleTest.java

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+package edu.hw2;
+
+import edu.hw2.Task2.Rectangle;
+import edu.hw2.Task2.Square;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+public class RectangleTest {
+    @Test
+    @DisplayName("Проверка LSP")
+    public void squareArea_shouldReturnCorrectSquareArea() {
+        Rectangle square = new Square(30);
+        double area = square.area();
+        assertThat(area).isEqualTo(900);
+    }
+
+    @Test
+    @DisplayName("Квадрату устанавливается ширина и высота")
+    public void squareArea_shouldReturnCorrectSquareArea_whenSquareHasWidthAndHeight() {
+        Rectangle square = new Square(30);
+        square = square.setHeight(99);
+        square = square.setWidth(20);
+        double area = square.area();
+        assertThat(area).isEqualTo(400);
+    }
+
+    @Test
+    @DisplayName("Квадрату устанавливается ширина и высота, но объект не изменяется")
+    public void squareArea_shouldReturnInitialSquareArea() {
+        Rectangle square = new Square(30);
+        square.setHeight(99);
+        square.setWidth(20);
+        double area = square.area();
+        assertThat(area).isEqualTo(900);
+    }
+
+}