JDBC driver getBoolean fails on null value

[escabe]

OrientDB Version: latest git version (commit d6fb8ec)

Java Version: 1.8.0_121-b13

OS: Windows 10

Expected behavior

I have a class myV with a property myBool which is of type Boolean. There are two records of type myV, the first record contains has a value for myBool (false) and the second record has myBool = null.

When I retrieve these records through the JDBC interface, I believe that I should be able to write:

// Execute query
Statement s = conn.createStatement();
ResultSet r = s.executeQuery("SELECT myBool FROM myV");
// Obtain meta data
ResultSetMetaData m = r.getMetaData();
int nCols = m.getColumnCount();
// Get the column types once and store them in an array
int colTypes[] = new int[nCols];
for (int i=0;i<nCols;i++) {
    colTypes[i] = m.getColumnType(i+1);
}

// Go through all rows and columns
while(r.next()) {
    for (int i=0;i<nCols;i++) {
        switch (colTypes[i]) {
            case java.sql.Types.BOOLEAN:
                boolean b = r.getBoolean(i+1);
                System.out.println(b);
                break;
            default:
                Object obj = r.getObject(i+1);
                System.out.println(obj);
                break;
        }
    }
}
r.close();
s.close();

There are three important assumptions/points in this code:

1. I only have to determine the types of the columns once; I mean this cannot change per row, right?

2. If the type is BOOLEAN, I should retrieve the value with getBoolean.

3. In my real code I have case statements for other types as well, not shown here, plus, also, shown here, always a fallback which uses getObject, which should always work.

Actual behavior

This errors out with

Exception in thread "main" java.sql.SQLException: An error occurred during the retrieval of the boolean value at column 'myBool' ---> {"@type":"d","@version":0,"myBool":null}
	at com.orientechnologies.orient.jdbc.OrientJdbcResultSet.getBoolean(OrientJdbcResultSet.java:379)
	at com.orientechnologies.orient.jdbc.OrientJdbcResultSet.getBoolean(OrientJdbcResultSet.java:369)
	at Main.main(Main.java:21)
Caused by: java.lang.NullPointerException
	at com.orientechnologies.orient.jdbc.OrientJdbcResultSet.getBoolean(OrientJdbcResultSet.java:375)
	... 2 more

The problem here is that getBoolean fails when the actual data is null.

Note by the way, that if I do not "cache" the column types and use m.getColumnType inside the while-loop, that getColumnType will return 0 once the second row is reached; which gets me into the default case which then works correctly. But the type of a column should not be changing when going through the rows, right?

Proposed fix

For now, I actually made a change to the JDBC driver, updated getBoolean to use Boolean object instead of boolean primitive and return false if value was null:

public boolean getBoolean(String columnLabel) throws SQLException {
  try {
    Boolean r = result.getProperty(columnLabel);
    if (r==null) {
      lastReadWasNull = true;
      return false;
    } else {
        return r;
    }
  } catch (Exception e) {
    throw new SQLException(
        "An error occurred during the retrieval of the boolean value at column '" + columnLabel + "' ---> " + result.toElement()
            .toJSON(), e);
  }

}

[luigidellaquila]

Hi @escabe

I just pushed a fix, it will be released with v 3.0.12

Thanks

Luigi