hw05-aop - задача на аспектно-ориентированное программирование

hw05-aop/build.gradle

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+plugins {
+    id 'java'
+}
+
+sourceCompatibility = JavaVersion.VERSION_17
+targetCompatibility = JavaVersion.VERSION_17
+
+dependencies {
+}

hw05-aop/src/main/java/ru/otus/Main.java

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+package ru.otus;
+
+import ru.otus.app.CalculateImpl;
+import ru.otus.app.Ioc;
+
+public class Main {
+    public static void main(String[] args) {
+        var calculate = Ioc.createCalculateLogImpl(new CalculateImpl());
+        calculate.calculation(1323);
+
+
+
+    }
+}

hw05-aop/src/main/java/ru/otus/app/Calculate.java

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+package ru.otus.app;
+
+
+public interface Calculate {
+    void calculation(int number);
+}

hw05-aop/src/main/java/ru/otus/app/CalculateImpl.java

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+package ru.otus.app;
+
+public class CalculateImpl implements Calculate {
+    @Log
+    @Override
+    public void calculation(int number) {
+        System.out.println(number + number);
+    }
+}

hw05-aop/src/main/java/ru/otus/app/Ioc.java

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+package ru.otus.app;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class Ioc {
+    private Ioc() {}
+
+    public static Calculate createCalculateLogImpl(Calculate calculate){
+        InvocationHandler invocationHandler = new MyHandler(calculate);
+        return (Calculate) Proxy.newProxyInstance(Ioc.class.getClassLoader(), new Class<?>[]{Calculate.class}, invocationHandler);
+
+    }
+    private static class MyHandler implements InvocationHandler {
+        private final Calculate calculate;
+        private final List<Method> methodsWithAnnotation;
+
+        MyHandler(Calculate calculate) {
+            this.calculate = calculate;
+            List<Method> methodsWithAnnotationCalculate = new ArrayList<>();
+
+            for (Method method : calculate.getClass().getDeclaredMethods()) {
+                for (Annotation annotation : method.getDeclaredAnnotations()) {
+                    if (annotation.annotationType() == Log.class) {
+                        methodsWithAnnotationCalculate.add(method);
+                    }
+                }
+            }
+            this.methodsWithAnnotation = methodsWithAnnotationCalculate;
+        }
+
+
+        @Override
+        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+            //проверяем по названию и по массиву аннотаций
+            for (Method annotatedMethod: methodsWithAnnotation) {
+                if (annotatedMethod.getName().equals(method.getName()) &&
+                        Arrays.toString(annotatedMethod.getParameterTypes()).equals(Arrays.toString(method.getParameterTypes()))) {
+                    System.out.println("выполняем метод " + method.getName() + ", параметры " + Arrays.toString(args));
+                    break;
+                }
+            }
+            return method.invoke(calculate, args);
+        }
+
+    }
+}

hw05-aop/src/main/java/ru/otus/app/Log.java

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+
+package ru.otus.app;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface Log {
+}