Java – use Oracle JDBC 12.1.0.1 (for 12c database) on a Oracle 10g database

Yes, the upwards and downwards compatibility is usually pretty good. I've successfully used such configuration several times in the past.

Having said that I remember one occasion, where we had a problem with calling a stored procedure that returned an open cursor to the Java application. Going back to an older version of the OJDBC driver solved it. At the time, it was a Oracle 9i database.

So with some testing, you can become confident it works.

Android R Update:

From Android R, this method always returns false. Google says that this is done "to protect goat privacy":

/**
 * Used to determine whether the user making this call is subject to
 * teleportations.
 *
 * <p>As of {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this method can
 * now automatically identify goats using advanced goat recognition technology.</p>
 *
 * <p>As of {@link android.os.Build.VERSION_CODES#R}, this method always returns
 * {@code false} in order to protect goat privacy.</p>
 *
 * @return Returns whether the user making this call is a goat.
 */
public boolean isUserAGoat() {
    if (mContext.getApplicationInfo().targetSdkVersion >= Build.VERSION_CODES.R) {
        return false;
    }
    return mContext.getPackageManager()
            .isPackageAvailable("com.coffeestainstudios.goatsimulator");
}

Previous answer:

From their source, the method used to return false until it was changed in API 21.

/**
 * Used to determine whether the user making this call is subject to
 * teleportations.
 * @return whether the user making this call is a goat 
 */
public boolean isUserAGoat() {
    return false;
}

It looks like the method has no real use for us as developers. Someone has previously stated that it might be an Easter egg.

In API 21 the implementation was changed to check if there is an installed app with the package com.coffeestainstudios.goatsimulator

/**
 * Used to determine whether the user making this call is subject to
 * teleportations.
 *
 * <p>As of {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this method can
 * now automatically identify goats using advanced goat recognition technology.</p>
 *
 * @return Returns true if the user making this call is a goat.
 */
public boolean isUserAGoat() {
    return mContext.getPackageManager()
            .isPackageAvailable("com.coffeestainstudios.goatsimulator");
}

Here is the source and the change.