我正在完成任务并且我差不多完成了，然而，有一个子弹告诉我在相邻组件之间画一条线以近似它们之间的距离。我到处搜索答案，但都没有奏效。 这是代码，我删除了不重要的事情，提前谢谢！
//IMPORTS
public class AssignLIRRBranches implements Runnable
{
static final String title = "LIRR Map";
static final String RK = "Ronkonkoma";
static final String MONTAUK = "Montauk";
static final String PJ = "Port_Jefferson";
static int width = 1200;
static int height = 600;
static int mapwidth = width-100;
static int mapheight = height-50;
double scalingFactorx;
double scalingFactory;
double scalingFactor;
double drawingX;
double drawingY;
double drawingY2;
MapPanel mapPanel = new MapPanel(new Font("Arial", Font.ITALIC, 12), false, Color.black, "kek", 12, 12, 12, 12);
JFrame application;
BoxLayout boxLayout;
Station station;
List<Station> stations = new ArrayList<Station>();
String[] larray;
JComboBox jbc;
public void run()
{
/* build the GUI */
application = new JFrame();
jbc = new JComboBox();
jbc.addItem(RK);
jbc.addItem(MONTAUK);
jbc.addItem(PJ);
boxLayout = new BoxLayout(application.getContentPane(), BoxLayout.Y_AXIS);
jbc.setMaximumSize(new Dimension(150, 15));
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.setTitle(title);
application.setSize(width, height);
application.setLayout(boxLayout);
mapPanel.setPreferredSize(new Dimension(mapwidth, mapheight));
application.add(mapPanel);
application.add(jbc);
application.setMinimumSize(application.getSize());
application.pack();
application.setMinimumSize(null);
application.setVisible(true);
}
void readStations(String path) throws FileNotFoundException, IOException {
/* read all stations */
try{ BufferedReader br = new BufferedReader(new FileReader(path));
String l;
while((l = br.readLine()) != null) {
larray = l.split(" ");
if(larray[2].equals(RK) || larray[2].equals(MONTAUK) || larray[2].equals(PJ)) {
/* construct and save Station instances */
station = new Station(Integer.parseInt(larray[0]), larray[1], larray[2], Double.parseDouble(larray[4]), Double.parseDouble(larray[5]));
stations.add(station);
}
}
} catch(NumberFormatException exc) {
System.out.println(exc);
}
}
public static void main(String[] args) throws FileNotFoundException, IOException {
String path = "lirr_sta_alpha.txt";
AssignLIRRBranches ars = new AssignLIRRBranches();
ars.readStations(path);
SwingUtilities.invokeLater(ars);
}
class Station {
int id = 0;
String NAME = " ";
String BRANCH = " ";
double latitude;
double longitude;
Station(int id, String NAME, String BRANCH, double longitude, double latitude) {
this.longitude = longitude;
this.latitude = latitude;
this.NAME = NAME;
this.BRANCH = BRANCH;
this.id = id;
}
//GETTERS AND SETTERS
}
class MapPanel extends JPanel implements ComponentListener {
Font mapFont;
boolean resized = false;
Color mapColor = Color.black;
String currentBranch;
double minLong, minLat, maxLong, maxLat;
MapPanel(Font mapFont, boolean resized, Color mapColor, String currentBranch, double minLong, double minLat, double maxLong, double maxLat) {
/* construct the MapPanel */
this.mapFont = mapFont;
this.resized = resized;
this.mapColor = mapColor;
this.currentBranch = currentBranch;
this.minLong = minLong;
this.minLat = minLat;
this.maxLong = maxLong;
this.maxLat = maxLat;
}
void extents() {
minLong = Double.MAX_VALUE;
minLat = Double.MAX_VALUE;
maxLong = -Double.MIN_VALUE;
maxLat = -Double.MIN_VALUE;
for(Station station : stations){
/* calculate minimum and maximum longitude and latitude for staions of the current branch */
if(station.getBranch().equals(jbc.getSelectedItem())) {
if(station.getLatitude()>maxLat){
maxLat = station.getLatitude();
maxLong = station.getLongitude();
}
if(station.getLatitude()<minLat){
minLat = station.getLatitude();
minLong = station.getLongitude();
}
}
}
}
public void paint(Graphics gr) {
Graphics2D g2 = (Graphics2D)gr;
if (null == mapFont) {
}
/* get the desired font and calulate margin values */
else
/* set the current font */
if (resized) {
/* rescale, taking into account margins */
}
/* set the color */
gr.setColor(mapColor);
/* iterate through the stations */
for (int i = 0; i < stations.size(); i++) {
if(stations.get(i).getBranch().equals(jbc.getSelectedItem())) {
//System.out.println(jbc.getSelectedItem());
/* calculate the corrdinates and draw the station name */
extents();
scalingFactorx = mapwidth/(maxLat - minLat);
scalingFactory = mapheight/(maxLong - minLong);
scalingFactor = Math.min(scalingFactorx, scalingFactory);
drawingX = (stations.get(i).getLatitude() - minLat) * scalingFactorx/1.1;
drawingY = (stations.get(i).getLongitude() - minLong) * scalingFactory/1.1;
drawingY2 = mapheight - drawingY;
gr.drawString(stations.get(i).getName(), (int)drawingX, (int)drawingY2-25);
//THIS IS WHERE I WANT TO DRAW A LINE
//gr.drawLine(I already tried using a ListIterator, it didn't work, tried getting the next element and it's values, didn't work, what can I do?);
}
}
mapPanel.addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
mapwidth = application.getWidth()-150;
mapheight = application.getHeight()-75;
application.repaint();
}
});
jbc.addActionListener (new ActionListener () {
public void actionPerformed(ActionEvent e) {
application.repaint();
}
});
}
}
}