Java命令jlist按状态

Question

i have a small problem, i don't know how to sort my jlist by status which is retrieved from database. i want sort by "online" and "offline", i mean online computers go first and then offline computers, i have this code now, it just makes the icon+text for the jlist

Can you tell me how can i filter/sortby status?

public void acx_pc(String query) {
    try {
        Statement st = con.createStatement();
        ResultSet rs = st.executeQuery(query);
        String comb;
        Map<Object, Icon> icons = new HashMap<>();
        ArrayList<String> pc_list = new ArrayList<>();
        int i = 0;


        while (rs.next()) {
            //Getting info from DB

            String pc_name = rs.getString("nombre_pc");
            String pc_ip = rs.getString("IP");
            String status = rs.getString("estado");
            //Setting text for the jList
            comb = pc_name + " - " + pc_ip;
            //Comparing Status
            switch (status) {
                case "online":
                    //This is just for rendering an image+text to Jlist
                    icons.put(comb, new ImageIcon(getClass().getResource("/Imagenes/com_on_30x30.png")));

                    break;
                case "offline":
                     //This is just for rendering an image to Jlist
                    icons.put(comb, new ImageIcon(getClass().getResource("/Imagenes/com_off_30x30.png")));
                    break;
            }
            //Adding info to ArrayList
            pc_list.add(i, comb);
            i++;

        }

        con.close();
        // Setting the list/text on Jlist
        Home.computer_jlist.setListData(pc_list.toArray());
        // create a cell renderer to add the appropriate icon
        Home.computer_jlist.setCellRenderer(new pc_cell_render(icons));

    } catch (Exception e) {
        System.out.println("Error aqui: " + e);

    }
}

I want to do something like (should automatically order) http://imageshack.us/a/img27/9018/2mx1.png

and not: http://imageshack.us/a/img407/346/e9r.png

Answer 1

You can sort your pc_list using the Collections.sort utility method a custom Comparator .

However, that's probably overkill. It would be easier to just use two lists:

ArrayList<String> pc_list = new ArrayList<>();
ArrayList<String> pc_offline_list = new ArrayList<>();

// . . .

switch (status) {
    case "online":
        //This is just for rendering an image+text to Jlist
        icons.put(comb, new ImageIcon(getClass().getResource("/Imagenes/com_on_30x30.png")));
        pc_list.add(comb);
        break;
    case "offline":
         //This is just for rendering an image to Jlist
        icons.put(comb, new ImageIcon(getClass().getResource("/Imagenes/com_off_30x30.png")));
        pc_offline_list.add(comb);
        break;
}

// . . .

pc_list.addAll(pc_offline_list);
Home.computer_jlist.setListData(pc_list.toArray());

So you keep the offline ones separate at first, and then tack them all onto the end one you've found them all. By keeping them separate avoid having to do any sorting!

Also, the add method adds to the end (appends) by default, so you'll notice that I just wrote pc_list.add(comb) instead of pc_list.add(i, comb) .