Bug #71924 StatementInterceptorV2.postProcess() exceptions swallows other exceptions

• Submitted: 4 Mar 2014 13:22
• Modified: 4 Mar 2014 13:23
• Reporter: Filipe Silva
• Status: Verified
• Category: Connector / J
• Severity: S3 (Non-critical)
• Version: 5.1.29
• OS: Any
• Assigned to: Filipe Silva
• CPU Architecture: Any

[4 Mar 2014 13:22] Filipe Silva

Description:
If the method StatementInterceptorV2.postProcess() throws an exception, it swallows any other that may have occurred while executing the main query.

How to repeat:
package mysql.interceptors;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import com.mysql.jdbc.ResultSetInternalMethods;
import com.mysql.jdbc.StatementInterceptorV2;

public class StatementInterceptorTest {
	private static final String CONNECTION_URL = "jdbc:mysql:///test?statementInterceptors="
			+ MyStatementInterceptor.class.getName();

	private static final String USERNAME = "myuser";
	private static final String PASSWORD = "mypass";

	public static void main(String[] args) throws Exception {
		Class.forName("com.mysql.jdbc.Driver");

		Connection conn = DriverManager.getConnection(CONNECTION_URL, USERNAME, PASSWORD);
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("SELECT c FROM t_original");

		rs.close();
		stmt.close();
		conn.close();
	}

	public static class MyStatementInterceptor implements StatementInterceptorV2 {
		public void init(com.mysql.jdbc.Connection conn, Properties props) throws SQLException {
		}

		public ResultSetInternalMethods preProcess(String sql, com.mysql.jdbc.Statement interceptedStatement,
				com.mysql.jdbc.Connection connection) throws SQLException {
			return null;
		}

		public boolean executeTopLevelOnly() {
			return true;
		}

		public void destroy() {
		}

		public ResultSetInternalMethods postProcess(String sql, com.mysql.jdbc.Statement interceptedStatement,
				ResultSetInternalMethods originalResultSet, com.mysql.jdbc.Connection connection, int warningCount,
				boolean noIndexUsed, boolean noGoodIndexUsed, SQLException statementException) throws SQLException {

			return (ResultSetInternalMethods) interceptedStatement.executeQuery("SELECT c FROM t_intercepted");
		}
	}
}

Suggested fix:
Chain exceptions thrown.

[4 Mar 2014 16:23] Filipe Silva

Posted by developer:
 
Instead of the postProcess() method above, the correct code example should contain:

public ResultSetInternalMethods postProcess(String sql, com.mysql.jdbc.Statement interceptedStatement,
		ResultSetInternalMethods originalResultSet, com.mysql.jdbc.Connection connection, int warningCount,
		boolean noIndexUsed, boolean noGoodIndexUsed, SQLException statementException) throws SQLException {

	if (sql.contains("t_original")) {
		return (ResultSetInternalMethods) interceptedStatement.executeQuery(sql.replace("t_original", "t_intercepted"));
	}
	return originalResultSet;
}