java多线程模拟并行计算框架

package concurrent;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;

//用十个线程计算一个数组的和
class TaskWithResult implements Callable<Integer> {
private Integer[] ints;

public TaskWithResult(Integer[] ints) {
this.ints = ints;
}

private int sumFromArray() {
int result = 0;
for (int a : this.ints) {
result += a;
}
return result;
}

@Override
public Integer call() throws Exception {
return sumFromArray();
}
}

public class Paiallel1 {
public static Integer[] segArray(int start, int end, int[] array) {
List<Integer> result = new ArrayList<Integer>();
for (int i = start; i < end; i++) {
result.add(array[i]);
}

Integer[] ary = result.toArray(new Integer[result.size()]);

return ary;
}

public static int getSum(int[] array) {
int result = 0;
for (int i = 0; i < array.length; i++) {
result += array[i];
}
return result;
}

public static void main(String[] args) throws InterruptedException,
ExecutionException {
long start1 = System.currentTimeMillis();
ExecutorService exec = Executors.newFixedThreadPool(10);
int[] array = { 300, 800, 89, 390, 892, 9384, 909, 1, 343, 5839, 939,
43, 355, 323, 32, 55, 3, 3, 43, 5, 5, 45, 555, 554, 554, 555,
545, 555, 553, 35, 2322, 332, 3232, 433, 344, 524, 245, 524,
6565, 526 };

List<FutureTask<Integer>> tasks = new ArrayList<FutureTask<Integer>>();

for (int i = 0; i < 10; i++) {
int incre = array.length / 10;
int start = i * incre;
int end = (i + 1) * incre;
if (end > array.length)
end = array.length;
Integer[] prt = segArray(start, end, array);

TaskWithResult calbTask = new TaskWithResult(prt);
FutureTask<Integer> task = new FutureTask<Integer>(calbTask);
tasks.add(task);
if (!exec.isShutdown()) {
exec.submit(task);
}
}

int result = 0;
for (FutureTask<Integer> task : tasks) {
int partRst = task.get();
result += partRst;
}
exec.shutdown();
long end1 = System.currentTimeMillis();
System.out.println("并行计算耗时：" + (end1 - start1));
System.out.println("并行计算的结果：" + result);

long start2 = System.currentTimeMillis();
int result2 = getSum(array);
long end2 = System.currentTimeMillis();

System.out.println("并行计算耗时：" + (end2 - start2));
System.out.println("单独计算的结果：" + result2);

}

}

package concurrent;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

//用十个线程计算一个数组的和
class TaskWithResult1 implements Callable<Integer> {
private Integer[] ints;

public TaskWithResult1(Integer[] ints) {
this.ints = ints;
}

private int sumFromArray() {
int result = 0;
for (int a : this.ints) {
result += a;
}
return result;
}

@Override
public Integer call() throws Exception {
return sumFromArray();
}
}

public class Paiallel2 {
public static Integer[] segArray(int start, int end, int[] array) {
List<Integer> result = new ArrayList<Integer>();
for (int i = start; i < end; i++) {
result.add(array[i]);
}

Integer[] ary = result.toArray(new Integer[result.size()]);

return ary;
}

public static int getSum(int[] array) {
int result = 0;
for (int i = 0; i < array.length; i++) {
result += array[i];
}
return result;
}

public static void main(String[] args) throws InterruptedException,
ExecutionException {
ExecutorService exec = Executors.newFixedThreadPool(10);
CompletionService<Integer> cplSvc = new ExecutorCompletionService<Integer>(
exec);

int[] array = { 300, 800, 89, 390, 892, 9384, 909, 1, 343, 5839, 939,
43, 355, 323, 32, 55, 3, 3, 43, 5, 5, 45, 555, 554, 554, 555,
545, 555, 553, 35, 2322, 332, 3232, 433, 344, 524, 245, 524,
6565, 526 };

for (int i = 0; i < 10; i++) {
int incre = array.length / 10;
int start = i * incre;
int end = (i + 1) * incre;
if (end > array.length)
end = array.length;
Integer[] prt = segArray(start, end, array);

TaskWithResult1 calbTask = new TaskWithResult1(prt);
if (!exec.isShutdown()) {
cplSvc.submit(calbTask);
}
}

int result = 0;
for (int i = 0; i < 10; i++) {
int partRst = cplSvc.take().get();
result += partRst;
}
exec.shutdown();
System.out.println("并行计算的结果：" + result);

int result2 = getSum(array);
System.out.println("单独计算的结果：" + result2);

}

}