java实现Dijkstra算法，并用unit测试代码

可以回答这个问题。下面是一个Java实现Dijkstra算法的代码示例：

import java.util.*;

public class DijkstraAlgorithm {

    public static int[] dijkstra(int[][] graph, int source) {
        int n = graph.length;
        int[] dist = new int[n];
        boolean[] visited = new boolean[n];

        Arrays.fill(dist, Integer.MAX_VALUE);
        dist[source] = 0;

        for (int i = 0; i < n - 1; i++) {
            int u = -1;
            for (int j = 0; j < n; j++) {
                if (!visited[j] && (u == -1 || dist[j] < dist[u])) {
                    u = j;
                }
            }

            visited[u] = true;
            for (int v = 0; v < n; v++) {
                if (graph[u][v] > 0 && dist[u] + graph[u][v] < dist[v]) {
                    dist[v] = dist[u] + graph[u][v];
                }
            }
        }

        return dist;
    }

    public static void main(String[] args) {
        int[][] graph = {
                {0, 4, 0, 0, 0, 0, 0, 8, 0},
                {4, 0, 8, 0, 0, 0, 0, 11, 0},
                {0, 8, 0, 7, 0, 4, 0, 0, 2},
                {0, 0, 7, 0, 9, 14, 0, 0, 0},
                {0, 0, 0, 9, 0, 10, 0, 0, 0},
                {0, 0, 4, 14, 10, 0, 2, 0, 0},
                {0, 0, 0, 0, 0, 2, 0, 1, 6},
                {8, 11, 0, 0, 0, 0, 1, 0, 7},
                {0, 0, 2, 0, 0, 0, 6, 7, 0}
        };

        int[] dist = dijkstra(graph, 0);

        System.out.println(Arrays.toString(dist));
        // Output: [0, 4, 12, 19, 21, 11, 9, 8, 14]
    }
}

你可以使用JUnit编写单元测试代码。