package com.example.concurrency.annotations;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Concurrent {
String value() default "";
}
package com.example.concurrency.tasks;
import com.example.concurrency.annotations.Concurrent;
@Concurrent
public class MyTask implements Runnable {
@Override
public void run() {
}
}
package com.example.concurrency.framework;
import com.example.concurrency.annotations.Concurrent;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
public class AnnotationParser {
public static List<Runnable> parseTasks(Class<?> clazz) {
List<Runnable> tasks = new ArrayList<>();
Annotation annotation = clazz.getAnnotation(Concurrent.class);
if (annotation != null) {
tasks.add(createTask(clazz));
}
Method[] methods = clazz.getDeclaredMethods();
for (Method method : methods) {
annotation = method.getAnnotation(Concurrent.class);
if (annotation != null) {
tasks.add(createTask(clazz, method));
}
}
return tasks;
}
private static Runnable createTask(Class<?> clazz) {
try {
return (Runnable) clazz.getDeclaredConstructor().newInstance();
} catch (Exception e) {
throw new RuntimeException("Failed to create task", e);
}
}
private static Runnable createTask(Class<?> clazz, Method method) {
try {
return (Runnable) method.invoke(clazz.getDeclaredConstructor().newInstance());
} catch (Exception e) {
throw new RuntimeException("Failed to create task", e);
}
}
}
package com.example.concurrency;
import com.example.concurrency.framework.AnnotationParser;
public class Main {
public static void main(String[] args) {
List<Runnable> tasks = AnnotationParser.parseTasks(ConcurrencyApp.class);
ExecutorService executor = Executors.newFixedThreadPool(tasks.size());
for (Runnable task : tasks) {
executor.submit(task);
}
executor.shutdown();
}
}
