support useLocalSessionState config, default is true

src/main/java/com/alibaba/druid/pool/DruidAbstractDataSource.java

@@ -231,12 +231,24 @@ public abstract class DruidAbstractDataSource extends WrapperAdapter implements
 
     private Boolean                                    useUnfairLock                             = null;
 
+    private boolean                                    useLocalSessionState                       = true;
+
     public DruidAbstractDataSource(boolean lockFair){
         lock = new ReentrantLock(lockFair);
 
         notEmpty = lock.newCondition();
         empty = lock.newCondition();
     }
+    
+    public boolean isUseLocalSessionState() {
+        return useLocalSessionState;
+    }
+    
+    public void setUseLocalSessionState(boolean useLocalSessionState) {
+        this.useLocalSessionState = useLocalSessionState;
+    }
+
+
 
     public boolean isOracle() {
         return isOracle;

src/main/java/com/alibaba/druid/pool/DruidConnectionHolder.java

@@ -195,18 +195,22 @@ public final class DruidConnectionHolder {
         // reset default settings
         if (underlyingReadOnly != defaultReadOnly) {
             conn.setReadOnly(defaultReadOnly);
+            underlyingReadOnly = defaultReadOnly;
         }
 
         if (underlyingHoldability != defaultHoldability) {
             conn.setHoldability(defaultHoldability);
+            underlyingHoldability = defaultHoldability;
         }
 
         if (underlyingTransactionIsolation != defaultTransactionIsolation) {
             conn.setTransactionIsolation(defaultTransactionIsolation);
+            underlyingTransactionIsolation = defaultTransactionIsolation;
         }
 
         if (underlyingAutoCommit != defaultAutoCommit) {
             conn.setAutoCommit(defaultAutoCommit);
+            underlyingAutoCommit = defaultAutoCommit;
         }
 
         connectionEventListeners.clear();

src/main/java/com/alibaba/druid/pool/DruidPooledConnection.java

@@ -671,6 +671,14 @@ public class DruidPooledConnection extends PoolableWrapper implements javax.sql.
     @Override
     public void setAutoCommit(boolean autoCommit) throws SQLException {
         checkState();
+        
+        boolean useLocalSessionState = holder.getDataSource().isUseLocalSessionState();
+        
+        if (useLocalSessionState) {
+            if (autoCommit == holder.isUnderlyingAutoCommit()) {
+                return;
+            }
+        }
 
         try {
             conn.setAutoCommit(autoCommit);