Test of https://gist.github.com/4144092

DistributedCacheTest.java

package com.kamatama41.sandbox4j;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.*;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.junit.Before;
import org.junit.Test;

public class DistributedCacheTest {

    private DistributedCache cache;
    @Before
    public void setUp() {
        List<String> nodes = Arrays.asList("a", "b", "c", "d", "e", "f");
        cache = new DistributedCache(nodes);
        // put 0-99
        for (int i = 0; i < 100; i++) {
            cache.put(i, "value"+i);
        }
        System.out.println("--------------------");
        printNodeCounts(100, "before");
    }

    @Test
    public void testGet() {
        distributedCheck();
    }

    @Test
    public void testAddNode() {
        cache.addNode("g");
        distributedCheck();
    }

    @Test
    public void testAddNode_someNodeKey() {
        cache.addNode("a");
        distributedCheck();
    }

    @Test
    public void testRemoveNode() {
        cache.removeNode("a");
        distributedCheck();
    }

    @Test
    public void testRemoveNode_notExistNode() {
        cache.removeNode("z");
        distributedCheck();
    }

    private void distributedCheck() {
        printNodeCounts(100, "0-99  ");
        for (int i = 0; i < 100; i++) {
            assertThat((String)cache.get(i), is("value"+i));
        }

        // put 100-199
        for (int i = 100; i < 200; i++) {
            cache.put(i, "value"+i);
        }
        printNodeCounts(200, "0-200 ");
        for (int i = 0; i < 200; i++) {
            assertThat((String)cache.get(i), is("value"+i));
        }
    }

    private void printNodeCounts(int count, String situation) {
        Map<String, Integer> nodeCounts = new HashMap<>();
        for (int i = 0; i < count; i++) {
            String node = cache.getNode(i);
            Integer nodeCount = nodeCounts.get(node);
            if(nodeCount == null) {
                nodeCount = 0;
            }
            nodeCounts.put(node, nodeCount+1);
        }
        System.out.println("[" + situation + "]:" + nodeCounts);
    }
}