支持HA

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@467 b9813039-fb51-4c41-a8b9-e21c2acb5095

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

@@ -22,7 +22,7 @@ public class HADataSource extends MultiDataSource implements DataSource {
 
     protected ArrayList<DruidDataSource>  dataSources             = new ArrayList<DruidDataSource>();
     protected final List<DruidDataSource> notAvailableDatasources = new CopyOnWriteArrayList<DruidDataSource>();
-
+    
     public HADataSource(){
 
     }
@@ -40,7 +40,7 @@ public class HADataSource extends MultiDataSource implements DataSource {
         return new MultiDataSourceConnection(this, createConnectionId());
     }
 
-    protected int indexFor(MultiDataSourceConnection multiDataSourceConnection, String sql) {
+    protected int indexFor(MultiDataSourceConnection multiDataSourceConnection, String sql) throws SQLException {
         int size = dataSources.size();
         int connectionId = (int) multiDataSourceConnection.getId();
 

src/main/java/com/alibaba/druid/pool/ha/balance/BalancePolicy.java

@@ -0,0 +1,9 @@
+package com.alibaba.druid.pool.ha.balance;
+
+import java.sql.SQLException;
+
+import com.alibaba.druid.pool.ha.MultiDataSourceConnection;
+
+public interface BalancePolicy {
+    int indexFor(MultiDataSourceConnection connection, String sql) throws SQLException;
+}

src/main/java/com/alibaba/druid/pool/ha/balance/RoundRobinBlancePolicy.java

@@ -0,0 +1,20 @@
+package com.alibaba.druid.pool.ha.balance;
+
+import java.sql.SQLException;
+
+import com.alibaba.druid.pool.ha.MultiDataSource;
+import com.alibaba.druid.pool.ha.MultiDataSourceConnection;
+
+public class RoundRobinBlancePolicy implements BalancePolicy {
+
+    @Override
+    public int indexFor(MultiDataSourceConnection connection, String sql) throws SQLException {
+        MultiDataSource dataSource = connection.getHaDataSource();
+
+        int size = dataSource.getDataSources().size();
+        long connectionId = (int) connection.getId();
+
+        return (int) (connectionId % size);
+    }
+
+}