我使用的是点类管理的(X,Y)坐标列表,我需要他们在十的Java如何排序点的ArrayList对象
我看了网上做的排序顺序一个实现比较器的新类PointCompare,但是我不确定这是如何工作的,因此我在sortByXCoordinates方法中有一个编译器错误。
帮助将不胜感激,并欢迎任何意见,在此先感谢。 下面是我的一些代码:
import javax.swing.JOptionPane;
import java.awt.Point;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
//import java.util.Iterator;
public class ConvexHullMain {
private Point coordinates = new Point(0, 0);
private final int MAX_POINTS = 3;
private ArrayList<Point> coordinateList = new ArrayList<Point>();
public void inputCoordinates() {
String tempString; // temp string for JOptionPane
int tempx = 0;
int tempy = 0;
for (int i = 0; i < MAX_POINTS; i++) {
try {
// input x coordinates
tempString = JOptionPane.showInputDialog(null,
"Enter X coordinate:");
tempx = Integer.parseInt(tempString);
// input y coordinates
tempString = JOptionPane.showInputDialog(null,
"Enter Y coordinate:");
tempy = Integer.parseInt(tempString);
coordinates.setLocation(tempx, tempy);// set input data into
// coordinates object
coordinateList.add(coordinates.getLocation()); // put in
// arrayList
} // end Try
catch (NumberFormatException e) {
System.err.println("ERROR!");
main(null);
} // end catch
}// end for loop
}
public void displayPoints() {
for (int i = 0; i < MAX_POINTS; i++) {
JOptionPane.showMessageDialog(null, "Point number " + (i + 1)
+ " is: " + coordinateList.get(i));
}
// alt method
// Iterator i = coordinateList.iterator();
// String outputTemp;
// while (i.hasNext()) {
// outputTemp = i.next().toString();
// JOptionPane.showMessageDialog(null, "Point number " + " is: "
// + outputTemp);
// }
}
/**
* This sorts the points by the X coordinates
*/
public void sortByXCoordinates(){
coordinateList.sort(coordinates, new PointCompare());
}
public class PointCompare implements Comparator<Point> {
public int compare(Point a, Point b) {
if (a.x < b.x) {
return -1;
} else if (a.x > b.x) {
return 1;
} else {
return 0;
}
}
}
public static void main(String[] args) {
ConvexHullMain main = new ConvexHullMain();
main.inputCoordinates();
main.displayPoints();
}
}
非常感谢你。这可以帮助我编写一个冒泡排序来手动排序! – user492837 2010-11-18 12:50:56
>使用冒泡排序。一次也没有。 – easymoden00b 2015-07-13 14:09:43