ha support

src/main/java/com/alibaba/druid/pool/ha/MultiDataSource.java

@@ -181,6 +181,10 @@ public abstract class MultiDataSource extends DataSourceAdapter implements Multi
     public void handleNotAwailableDatasource(DataSourceHolder dataSourceHolder) {
         dataSourceHolder.setEnable(false);
     }
+    
+    public String[] getDataSourceNames() {
+        return this.dataSources.keySet().toArray(new String[this.dataSources.size()]);
+    }
 
     @Override
     public String getDbType() {
@@ -216,6 +220,16 @@ public abstract class MultiDataSource extends DataSourceAdapter implements Multi
     public long createTransactionId() {
         return transactionIdSeed.incrementAndGet();
     }
+    
+    public boolean restartDataSource(String name) {
+        DataSourceHolder holder = this.getDataSources().get(name);
+        if (holder != null) {
+            holder.restart();
+            return true;
+        }
+        
+        return false;
+    }
 
     class FailureDetectTask implements Runnable {