java - The declared package does not match the expected package ""

Question

I am using Eclipse and have not used Java for sometime. However, I can compile my code on the command-line just fine and generate the necessary .class files. In Eclipse, it complains that The declared package "Devices" does not match the expected package "". What does this mean and how can I fix it?

Sample code:

package Devices;

public final class DevFrequency 
{
    public short messageID;
    public double frequency;
    public short converterID;
    public DevFrequency() 
    {
    }
    public DevFrequency(short _messageID,double _frequency,short _converterID)
    {
        messageID = _messageID;
        frequency = _frequency;
        converterID = _converterID;
    }
}

The name of my project is DeviceDDS.

Answer 1

Try closing and re-opening the file.

It is possible to get this error in eclipse when there is absolutely nothing wrong with the file location or package declaration. Try that before spending a lot of time trying these other solutions. Sometimes eclipse just gets confused. It's worked for me on a number of occasions. I credit the idea to Joshua Goldberg.