org.postgresql.util.PGobject is in unnamed module of loader 'app'

[dirkluijk]

Please read https://stackoverflow.com/help/minimal-reproducible-example

Describe the issue
A clear and concise description of what the issue is.

Driver Version?
42.2.23 and 42.2.24

Java Version?
openjdk 15.0.1

OS Version?
Mac OS

PostgreSQL Version?
Postgres 10

Since version 42.2.23 we get this error:

java.lang.ClassCastException: class java.lang.String cannot be cast to class org.postgresql.util.PGobject (java.lang.String is in module java.base of loader 'bootstrap'; org.postgresql.util.PGobject is in unnamed module of loader 'app')

maybe it's related to
#2153 or #1949 (not sure though)

Any ideas?

[davecramer]

Do you have the rest of the exception. I'd like to see what happens before this is thrown.

[dirkluijk]

I checked, the code was was doing something like this:

Object[] values =  (Object[]) resultSet.getArray("some-field").getArray();
String firstValue = ((PGobject) values[0]).getValue()

I changed it to:

Object[] values = (Object[]) resultSet.getArray("some-field").getArray();
String firstValue = (String) values[0];

which can be simplified to:

String[] values = (String[]) resultSet.getArray("some-field").getArray();
String firstValue = values[0];

That fixed it. Which is fine for us, but maybe good to know that it was a breaking change.

[dirkluijk]

It seems to affect enum arrays. I looks like it's now automatically returned like an array of strings instead of a PGobject (which is actually an improvement imho). 😄

before:

Map<String, Object> actionDefault = template.queryForMap("SELECT * FROM ...");
assertThat(actionDefault).containsEntry("action", create("someType", "SOME_VALUE"));

private static PGobject create(String type, String value) {
    PGobject pGobject = new PGobject();
    pGobject.setType(type);
    try {
        pGobject.setValue(value);
    } catch (SQLException e) {
        throw new IllegalArgumentException(e);
    }
    return pGobject;
}

after:

Map<String, Object> actionDefault = template.queryForMap("SELECT * FROM ...");
assertThat(actionDefault).containsEntry("action", "SOME_VALUE");