remove clearParameter log error

src/test/java/com/alibaba/druid/bvt/pool/ExceptionSorterTest.java

@@ -0,0 +1,49 @@
+package com.alibaba.druid.bvt.pool;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.mock.MockConnection;
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.pool.vendor.MockExceptionSorter;
+
+public class ExceptionSorterTest extends TestCase {
+
+    private DruidDataSource dataSource;
+
+    protected void setUp() throws Exception {
+        dataSource = new DruidDataSource();
+        dataSource.setUrl("jdbc:mock:xxx");
+        dataSource.setTestOnBorrow(true);
+        dataSource.setDbType("mysql");
+        dataSource.setPoolPreparedStatements(true);
+
+        dataSource.init();
+    }
+
+    protected void tearDown() throws Exception {
+        dataSource.close();
+    }
+
+    public void test_exceptionSorter() throws Exception {
+        Assert.assertTrue(dataSource.getExceptionSorterClassName(),
+                          dataSource.getExceptionSorter() instanceof MockExceptionSorter);
+
+        Connection conn = dataSource.getConnection();
+        MockConnection mockConn = conn.unwrap(MockConnection.class);
+
+        PreparedStatement stmt = conn.prepareStatement("select 1");
+
+        stmt.execute();
+        
+        mockConn.close();
+
+        stmt.close();
+
+        conn.close();
+    }
+}