add some logs to RandomDataSourceSelector

src/main/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceSelector.java

@@ -216,6 +216,8 @@ public class RandomDataSourceSelector implements DataSourceSelector {
             for (DataSource b : blacklist) {
                 dataSourceSet.remove(b);
             }
+            LOG.info(blacklist.size() + " Blacklist DataSource removed, return "
+                    + dataSourceSet.size() + " DataSource(s).");
         }
         return dataSourceSet;
     }
@@ -228,6 +230,7 @@ public class RandomDataSourceSelector implements DataSourceSelector {
             }
         }
         if (!busyDataSourceSet.isEmpty() && busyDataSourceSet.size() < dataSourceSet.size()) {
+            LOG.info("Busy DataSouces: " + busyDataSourceSet.size() + "/" + dataSourceSet.size());
             for (DataSource ds : busyDataSourceSet) {
                 dataSourceSet.remove(ds);
             }

src/test/java/com/alibaba/druid/pool/ha/node/FileNodeListenerTest.java

@@ -100,7 +100,7 @@ public class FileNodeListenerTest {
         String file = "/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties";
         FileNodeListener listener = new FileNodeListener();
         listener.setFile(file);
-        listener.setPrefix("prefix3");
+        listener.setPrefix("prefix0");
         List<NodeEvent> list = listener.refresh();
 
         assertTrue(listener.getProperties().isEmpty());

src/test/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceSelectorSingleDataSourceTest.java

@@ -0,0 +1,97 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.pool.ha.HighAvailableDataSource;
+import com.alibaba.druid.support.logging.Log;
+import com.alibaba.druid.support.logging.LogFactory;
+
+public class RandomDataSourceSelectorSingleDataSourceTest {
+    private final static Log LOG = LogFactory
+            .getLog(RandomDataSourceSelectorSingleDataSourceTest.class);
+
+    private HighAvailableDataSource highAvailableDataSource;
+
+    @Before
+    public void setUp() throws Exception {
+        highAvailableDataSource = new HighAvailableDataSource();
+        String file = "/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties";
+        highAvailableDataSource.setDataSourceFile(file);
+        highAvailableDataSource.setPropertyPrefix("prefix3");
+        highAvailableDataSource.setMaxActive(2);
+        highAvailableDataSource.setMaxWait(500);
+        highAvailableDataSource.setInitialSize(2);
+        initSelector(highAvailableDataSource);
+        highAvailableDataSource.init();
+    }
+
+    @After
+    public void tearDown() {
+        highAvailableDataSource.destroy();
+        highAvailableDataSource = null;
+    }
+
+    @Test
+    public void testGetWhileBlacklistIsEmpty() {
+        RandomDataSourceSelector selector = (RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector();
+        DruidDataSource dataSource = (DruidDataSource) highAvailableDataSource.getAvailableDataSourceMap()
+                .get("prefix3.foo");
+        assertNotNull(selector.get());
+        assertFalse(dataSource.isTestOnReturn());
+    }
+
+    @Test
+    public void testGetWhileBlacklisted() throws Exception {
+        RandomDataSourceSelector selector = (RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector();
+        DruidDataSource dataSource = (DruidDataSource) highAvailableDataSource.getAvailableDataSourceMap()
+                .get("prefix3.foo");
+        dataSource.setValidationQuery("select xxx from yyy");
+
+        Thread.sleep(10 * 1000);
+        assertTrue(dataSource.isTestOnReturn());
+        for (int i = 0; i < 5; i++) {
+            assertNotNull(selector.get());
+            Thread.sleep(1000);
+        }
+    }
+
+    @Test
+    public void testGetAfterRecovering() throws Exception {
+        RandomDataSourceSelector selector = (RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector();
+        DruidDataSource dataSource = (DruidDataSource) highAvailableDataSource.getAvailableDataSourceMap()
+                .get("prefix3.foo");
+        dataSource.setValidationQuery("select xxx from yyy");
+
+        Thread.sleep(10 * 1000);
+        assertTrue(dataSource.isTestOnReturn());
+        assertNotNull(selector.get());
+        Thread.sleep(10 * 1000);
+        assertTrue(dataSource.getPoolingCount() == 0);
+
+        dataSource.setValidationQuery("values current_timestamp");
+        Thread.sleep(10 * 1000);
+        assertFalse(dataSource.isTestOnReturn());
+        assertNotNull(selector.get());
+        assertTrue(dataSource.getPoolingCount() > 0);
+    }
+
+    private RandomDataSourceSelector initSelector(HighAvailableDataSource dataSource) {
+        RandomDataSourceSelector selector = new RandomDataSourceSelector(dataSource);
+        RandomDataSourceValidateThread validateThread = new RandomDataSourceValidateThread(selector);
+        RandomDataSourceRecoverThread recoverThread = new RandomDataSourceRecoverThread(selector);
+        validateThread.setCheckingIntervalSeconds(3);
+        recoverThread.setRecoverIntervalSeconds(3);
+        selector.setValidateThread(validateThread);
+        selector.setRecoverThread(recoverThread);
+        selector.init();
+        dataSource.setDataSourceSelector(selector);
+        return selector;
+    }
+}

src/test/resources/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties

@@ -4,5 +4,6 @@ prefix1.foo.password=foo_password
 prefix2.foo.url=jdbc:derby:memory:foo2;create=true
 prefix2.foo.username=bar
 prefix2.foo.password=bar_password
+prefix3.foo.url=jdbc:derby:memory:foo3;create=true
 foo.url=jdbc:derby:memory:foo3;create=true
 bar=jdbc:derby:memory:bar;create=true