Sort list of objects and Comparator.

Question

Hi. I have a problem with list sorting. There is a class with fields like these id (Long), number (String), operator (String), server (String) port (Integer). I have to sort list of these objects in accordance with the conditions specified by the user.
Conditions for sorting:
1. In the first account of the full compliance of the server name and port value (Object Gateway) specifed by the user.
2. When the server name is correct and the port is different from the standard, then the objects should be placed in ascending order of the port.
3. If the server name does not match the model, the order of the objects must reflect the declining value of a parameter port. If the list contains objects of the same port and different name, the order does not matter.
How should Comparator looks like?

Answer 1

Ok, this is the solution ;]
public class GatewayComparator implements Comparator<Gateway> {
    private String server;
    private Integer port;
    public GatewayComparator(String server, Integer port){
        this.server = server;
        this.port = port;
    public int compare(Gateway o1, Gateway o2) {
        int result = 0;
        if (o1.getServer().equals(this.server)) {
            result = -1;
        if (o2.getServer().equals(this.server)) {
            result = 1;
        if (o1.getServer().equals(this.server) && o2.getServer().equals(this.server)) {
            if (o1.getPort().equals(this.port)) {
                result = -1;
            if (o2.getPort().equals(this.port)) {
                result = 1;
            } else if (!o1.getPort().equals(this.port) && !o2.getPort().equals(this.port)) {
                result = o1.getPort().compareTo(o2.getPort());
        } else if (!o1.getServer().equals(this.server) && !o2.getServer().equals(this.server)) {
            if (o1.getPort() > o2.getPort()) {
                result = -1;
            } else if (o1.getPort() < o2.getPort()) {
                result = 1;
            } else {
                result = 0;
        return result;
}