SQL query join issue in Java program

I have a class that contains methods that connect to a database, run a query, and assigns data from the database into variables.

The purpose of this Java program is to scan a database that houses information on security threats for client's servers. When the query is run it should return selected data fields from 2 tables (target_stats and attack_stats) upon reading that the number of attacks (target_stats.num_attacks) is above 0.

I can successfully retrieve data from the target table but I get null values from the attacker table and I know that the field is not null in the database.

My question: can anyone detect an error, most likely a logical one, in my query that is causing the unfavorable results? I am a beginner programmer and fairly new to SQL.

Also, I am in the process of learning setters and getters in this program, all of the retrieved data is to be used in another class but I am testing and learning with just the target field for now. Perhaps that is causing an issue?

UPDATE I rant he query in MySQL query browser and get the same unfavorable result, so the problem is just in my query logic. I have done some research in queries and joins but must still be lacking suitable knowledge.

My code (hopefully I post it correctly in format):

public class Database {

String details = null;
int threat_level = 0;
ResultSet rslt = null;

private String target2;

Connection con;
public void createConnection() {

    //Establish a connection
    try {
        con = DriverManager.getConnection("sensitiveInformation");
    } catch (SQLException e) {

        e.printStackTrace();
    }
    System.out.println("Database connected");
}

public ResultSet getData() {

    String query =  "SELECT target_stats.server_id, target_stats.target, target_stats.threat_level, target_stats.client_id, attack_stats.attacker, attack_stats.num_this_attack " +
            "       FROM target_stats " +
            "       LEFT OUTER JOIN attack_stats " +
            "       ON target_stats.target = attack_stats.target " +
            "       WHERE target_stats.num_attacks > '0' " +
            "       AND target_stats.interval_id>'2'";
    Statement stmt = null;
    try {
        stmt = con.createStatement();
    } catch (SQLException e) {

        e.printStackTrace();
    }

    try {
        rslt = stmt.executeQuery(query);
    } catch (SQLException e) {

        e.printStackTrace();
    }

    return rslt;    

}

public void process() {

    try {


        String server_id = rslt.getString("server_id");
        target2 = rslt.getString("target");
        threat_level = rslt.getInt("threat_level");
        int client_id = rslt.getInt("client_id");
        String attacker = rslt.getString("attacker");
        String num_this_attack = rslt.getString("num_this_attack");
        details = "Target IP: " + target2 + " Server ID: " + server_id + " Client ID: " + client_id + " Threat Level: " + threat_level  + " Attacker IP: " + attacker + " Number of attacks: " + num_this_attack;


        System.out.println(details);


    } catch (SQLException e) {

        e.printStackTrace();
    }
}
public String getTraget2() {
    return target2;
}

}

Update: I should mention that I have a while loop in another class that properly reads through each record.

Update 2: Here is the main class, I am not concerned with the GUI elements right now:

public class MainDisplay extends JFrame {

static Toolkit tk = Toolkit.getDefaultToolkit();
static int Width = (int)tk.getScreenSize().getWidth();
static int Height = (int)tk.getScreenSize().getHeight();

public static JFrame frame = new JFrame();
public static JLayeredPane lpane = new JLayeredPane();
public static String target;

public static void main (String[] args) { new MainDisplay();

}

public MainDisplay() {

frame.setPreferredSize(new Dimension(Width, Height));
frame.setLocation(0,0);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setUndecorated(true);

//NoRisk Run = new NoRisk();
//Run.NoThreat();


ThreatPanel Run = new ThreatPanel();
Database Data = new Database();

//Create Connection to Database and run query

Data.createConnection();
Data.getData();
    try {
        while(Data.rslt.next()){
            Data.process();
            Run.TargetServer = Data.getTraget2();
            System.out.print(Data.getTraget2()); //for testing purposes
            Run.ShowThreats();
            try {
                Thread.sleep(1000*10); // sleeps for ten seconds
            } catch (InterruptedException e) {

                e.printStackTrace();
            }

        }
    } catch (SQLException e) {

        e.printStackTrace();
    }

//Run.ShowThreats();

frame.setLayout(new BorderLayout());
frame.add(lpane, BorderLayout.CENTER);
lpane.setBounds(0,0, Width, Height);






frame.pack();
frame.setVisible(true);

} }