JAVA編程思想第四版-多線程的練習答案之練習10

package exercise.exercise10;

import java.util.ArrayList;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class MainFibonacci {

	static int count=0;
	public MainFibonacci(int n) {

		System.out.println("exercise " + n);
	}

	public static void main(String[] args) {
		ExecutorService es = Executors.newCachedThreadPool();
		ArrayList<Future<Integer>> resultList = new ArrayList<Future<Integer>>();
		for (int i = 1; i < 10; i++) {
			// resultList.add(es.submit(new MainFibonacci(i)));//練習5的實現方式
			resultList.add(es.submit(new Callable<Integer>() {

				@Override
				public Integer call() throws Exception {
					return runTask(count++);
				}

				private Integer runTask(int count) {
					return getFibonacciInner(count);
				}
			}));
		}
		ArrayList<Integer> futureList = new ArrayList<Integer>();
		for (Future<Integer> future : resultList) {
			try {
				futureList.add(future.get());
			} catch (InterruptedException e) {
				e.printStackTrace();
			} catch (ExecutionException e) {
				e.printStackTrace();
			} finally {
				es.shutdown();
			}
		}

		Integer[] sequence = new Integer[futureList.size()];
		sequence[0] = futureList.get(0);
		for (int i = 1; i < futureList.size(); i++) {
			sequence[i] = sequence[i - 1] + futureList.get(i);
		}
		for (int i = 0; i < sequence.length; i++) {
			System.out.println("第" + (i+1) + "fibonacci的數爲：" + futureList.get(i));
		}
		for (int i = 0; i < sequence.length; i++) {
			System.out.println("前" + (i+1) + "fibonacci的值總和爲：" + sequence[i]);
		}
	}

	public static int getFibonacciInner(int fibo) {
		if (0 == fibo) {
			return 0;
		}
		if (fibo < 2) {
			return 1;
		}
		return getFibonacciInner(fibo - 1) + getFibonacciInner(fibo - 2);
	}
}
/**
 * 前1fibonacci的值總和爲：0 前2fibonacci的值總和爲：1 前3fibonacci的值總和爲：2 前4fibonacci的值總和爲：4
 * 前5fibonacci的值總和爲：7 前6fibonacci的值總和爲：12 前7fibonacci的值總和爲：20
 * 前8fibonacci的值總和爲：33 前9fibonacci的值總和爲：54
 * 
 */

JAVA編程思想第四版21章，第669頁，練習10的答案，如果發現錯誤，請多指正！