user clearDefines optimize Oracle PrepareStatement Cache memoery use

src/test/java/com/alibaba/druid/pool/TestOraclePreparedStatement.java

@@ -0,0 +1,59 @@
+package com.alibaba.druid.pool;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+
+import junit.framework.TestCase;
+import oracle.jdbc.driver.OraclePreparedStatement;
+
+import com.alibaba.druid.util.JdbcUtils;
+
+public class TestOraclePreparedStatement extends TestCase {
+
+    private String jdbcUrl;
+    private String user;
+    private String password;
+
+    public void setUp() throws Exception {
+        jdbcUrl = "jdbc:oracle:thin:@10.20.149.85:1521:ocnauto";
+        // jdbcUrl = "jdbc:oracle:thin:@20.20.149.85:1521:ocnauto"; // error url
+        user = "alibaba";
+        password = "ccbuauto";
+    }
+
+    public void test_0() throws Exception {
+        Class.forName(JdbcUtils.getDriverClassName(jdbcUrl));
+
+        Connection conn = DriverManager.getConnection(jdbcUrl, user, password);
+
+        // ResultSet metaRs = conn.getMetaData().getTables(null, "ALIBABA", null, new String[] {"TABLE"});
+        // JdbcUtils.printResultSet(metaRs);
+        // metaRs.close();
+
+        OraclePreparedStatement oracleStmt = null;
+        PreparedStatement stmt = conn.prepareStatement("SELECT ? FROM DUAL");
+        oracleStmt = (OraclePreparedStatement) stmt;
+        {
+            
+            stmt.setString(1, "aaa");
+            ResultSet rs = stmt.executeQuery();
+            rs.next();
+
+            rs.close();
+            
+            oracleStmt.clearDefines();
+        }
+        {
+            stmt.setString(1, "bbb");
+            ResultSet rs = stmt.executeQuery();
+            rs.next();
+            
+            rs.close();
+            stmt.close();
+        }
+
+        conn.close();
+    }
+}

src/test/java/com/alibaba/druid/pool/TestOracle_DruidDataSource.java

@@ -29,6 +29,7 @@ public class TestOracle_DruidDataSource extends TestCase {
     public void test_0() throws Exception {
         final String SQL = "SELECT SYSDATE FROM DUAL";
         final DruidDataSource dataSource = new DruidDataSource();
+        dataSource.setInitialSize(1);
         dataSource.setUrl(jdbcUrl);
         dataSource.setUsername(user);
         dataSource.setPassword(password);