java - 避免使用 lambda 表达式

Question

我正在创建一个 Android 应用程序，我想使用以下代码。

import java.util.Arrays;
import static java.util.Arrays.stream;
import java.util.concurrent.*;


    public class VogelsApproximationMethod {

        final static int[] demand = {30, 20, 70, 30, 60};
        final static int[] supply = {50, 60, 50, 50};
        final static int[][] costs = {{16, 16, 13, 22, 17}, {14, 14, 13, 19, 15},
        {19, 19, 20, 23, 50}, {50, 12, 50, 15, 11}};

        final static int nRows = supply.length;
        final static int nCols = demand.length;

        static boolean[] rowDone = new boolean[nRows];
        static boolean[] colDone = new boolean[nCols];
        static int[][] result = new int[nRows][nCols];

        static ExecutorService es = Executors.newFixedThreadPool(2);

        public static void main(String[] args) throws Exception {
            int supplyLeft = stream(supply).sum();
            int totalCost = 0;

            while (supplyLeft > 0) {
                int[] cell = nextCell();
                int r = cell[0];
                int c = cell[1];

                int quantity = Math.min(demand[c], supply[r]);
                demand[c] -= quantity;
                if (demand[c] == 0)
                    colDone[c] = true;

                supply[r] -= quantity;
                if (supply[r] == 0)
                    rowDone[r] = true;

                result[r][c] = quantity;
                supplyLeft -= quantity;

                totalCost += quantity * costs[r][c];
            }

            stream(result).forEach(a -> System.out.println(Arrays.toString(a)));
            System.out.println("Total cost: " + totalCost);

            es.shutdown();
        }

        static int[] nextCell() throws Exception {


          **Future<int[]> f1 = es.submit(() -> maxPenalty(nRows, nCols, true));
            Future<int[]> f2 = es.submit(() -> maxPenalty(nCols, nRows, false));**


            int[] res1 = f1.get();
            int[] res2 = f2.get();

            if (res1[3] == res2[3])
                return res1[2] < res2[2] ? res1 : res2;

            return (res1[3] > res2[3]) ? res2 : res1;
        }

        static int[] diff(int j, int len, boolean isRow) {
            int min1 = Integer.MAX_VALUE, min2 = Integer.MAX_VALUE;
            int minP = -1;
            for (int i = 0; i < len; i++) {
                if (isRow ? colDone[i] : rowDone[i])
                    continue;
                int c = isRow ? costs[j][i] : costs[i][j];
                if (c < min1) {
                    min2 = min1;
                    min1 = c;
                    minP = i;
                } else if (c < min2)
                    min2 = c;
            }
            return new int[]{min2 - min1, min1, minP};
        }

        static int[] maxPenalty(int len1, int len2, boolean isRow) {
            int md = Integer.MIN_VALUE;
            int pc = -1, pm = -1, mc = -1;
            for (int i = 0; i < len1; i++) {
                if (isRow ? rowDone[i] : colDone[i])
                    continue;
                int[] res = diff(i, len2, isRow);
                if (res[0] > md) {
                    md = res[0];  // max diff
                    pm = i;       // pos of max diff
                    mc = res[1];  // min cost
                    pc = res[2];  // pos of min cost
                }
            }
            return isRow ? new int[]{pm, pc, mc, md} : new int[]{pc, pm, mc, md};
        }
    }

问题是我想避免使用 lambda 表达式。如果有人可以帮助如何重写以下内容，我将不胜感激。

Future<int[]> f1 = es.submit(() -> maxPenalty(nRows, nCols, true));
Future<int[]> f2 = es.submit(() -> maxPenalty(nCols, nRows, false));

Answer 1

您始终可以只使用匿名内部类:

Future<int[]> f1 = es.submit(new Callable<int[]>() {
  @Override public int[] call() {
    return maxPenalty(nRows, nCols, true);
  }
});

...然后 f2 也一样。