Wrong isAssignableFrom check in org.geolatte.geom.codec.db.oracle.DefaultConnectionFinder:65

[harald-berger]

The Class.isAssignableFrom(Class) call in line 65 is backwards. We have an agent that instruments classes that implement java.sql.Connection. It adds a getter method that returns java.lang.Object. With the agent injected, since the isAssignableCheck is backwards, a ClassCastException is thrown. The fix is easy: (java.sql.Connection.class.isAssignableFrom(method.getReturnType())) I believe this was the orignal intention, like: (methodReturnValue instanceof java.sql.Connection) Class.isAssignableFrom must always be called reverse to it's "instanceof" counterpart.

I'm appending a small demo program to reproduce the issue.

package foo;

public class Foo {

interface Connection {
    String getName();
}

interface I1 {
    Connection getConnection();
    Object getConnectionData();
}

static class Impl1 implements I1 {

    @Override
    public Connection getConnection() {
        return new Connection() {

            @Override
            public String getName() {
                return "ValidConnection";
            }
        };
    }

    @Override
    public Object getConnectionData() {
        return "CData";
    }
}

public static void main(String[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
    foo(new Impl1());
}

private static void foo(Impl1 o) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
    for (Method method : o.getClass().getMethods()) {
// if (Connection.class.isAssignableFrom(method.getReturnType())) { // CORRECT
if (method.getReturnType().isAssignableFrom(Connection.class)) { // WRONG
Connection c = (Connection) method.invoke(o);
System.out.println(c.getName());
} else {
System.out.println("Skip: "+method);
}
}
}
}