How to get server messages (raise notice) from PostgreSQL function that was invoked through MyBatis mapper method?

Question

When running a plain JDBC statement, the output messages produced through raise notice commands in a PostgreSQL function can be fetched using Statement.getWarnings() , eg:

try (CallableStatement callableStatement = connection.prepareCall("select my_func()")) {
    callableStatement.execute();
    // ... do something with the output ...
    SQLWarning sqlWarning = callableStatement.getWarnings();
    while (sqlWarning != null) {
      System.out.println(sqlWarning.getMessage());
      sqlWarning = sqlWarning.getNextWarning();
    }
}

Is there a way to fetch that same output after running a MyBatis mapper method, without resorting to raw JDBC?

Answer 1

Unless a better option is suggested, I was able to fetch that output using a MyBatis interceptor. The interceptor code:

@Intercepts({
        @Signature(type = StatementHandler.class, method = "update", args = {Statement.class})})
public class FetchStatementWarningsInterceptor implements Interceptor {

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        Object[] args = invocation.getArgs();
        if (args == null || args.length != 1 || !(args[0] instanceof Statement)) {
            return invocation.proceed();
        }
        Statement statement = (Statement) args[0];
        Object result = invocation.proceed();
        if (!statement.isClosed()) {
            SQLWarning sqlWarning = statement.getWarnings();
            // ... do something with the warnings output ...
        }
        return result;
    }

}