在列表视图上显示 hashmap 键，然后单击显示 hashmap 值的对话框

Question

I have a table named restaurants. It has a filed 'name' and 'location'. I wanna create a listView where I show all the names of restaurants, but on click of a listView item, I wanna show an alert(dialog) with its location. I have saved the data from the database in a HashMap but on alert, it shows the name of the restaurant. How can I show the location? Here is my code:

 public void populateData() throws SQLException {
        Connection c = DriverManager.getConnection("jdbc:sqlite:src/main/resources/com/example/database/SmartCity.db");
        Statement stmt = c.createStatement();
        String sql = "SELECT * FROM restaurants";
        ResultSet rs = stmt.executeQuery(sql);
        HashMap<String,String> restaurants = new HashMap<>();
        while (rs.next()){
            restaurants.put(rs.getString("name"),rs.getString("location"));
        }
        rs.close();
        stmt.close();
        for(String restaurant : restaurants .keySet()){
            restaurantList.getItems().add(restaurant);
        }
    }

    public void handleItemClick(){
        restaurantList.setOnMouseClicked(mouseEvent -> {
            String selectedItem = restaurantList.getSelectionModel().getSelectedItem().toString();
            System.out.println(restaurantList.getSelectionModel());
            Dialog d = new Alert(Alert.AlertType.INFORMATION,selectedItem);
            d.show();
        });

    }

Answer 1

This is strictly my option, but I think you're going about it the wrong way. Here's how I would do it:

1. Create a Restaurant with fields for Name and Location.
2. Instead of loading into a map, create Restaurant objects and add those to the ListModel
3. Create ListCellRenderer by extending DefaultListCellRenderer, calling super.getListCellRendererComponent, and then setting the text to that of the item.name.
4. On the item click handler you get the name from the selectedItem, cast it to Restaurant, and then get the location from that.

Edit: The benefit to extra work is if you ever add information to the Restaurant (type of food, number of yelp star, distance from user, etc), you can modify your renderer display that information. You can add icons, change background color, etc.