添加CLASSPATH后，无法找到或加载主类

Question

Hi I'm doing Princeton Algorithms assignment when I ran into the following problem.

Both BruteCollinearPoints.java and input8.txt are in C:\\Users\\Jen\\Desktop\\princeton-algorithms\\collinear .

I have been trying to run java-algs4 BruteCollinearPoints input8.txt from the aforementioned path to no avail. I kept getting Error: Could not find or load main class BruteCollinearPoints .

Below is my classpath:

CLASSPATH: C:\\Users\\Jen\\algs4\\algs4.jar;

Answer 1

First of all you need to make sure that your BruteCollinearPoints class has main method. It could look like the following

import java.util.ArrayList;
import java.util.Arrays;
import edu.princeton.cs.algs4.In;
import edu.princeton.cs.algs4.StdDraw;
import edu.princeton.cs.algs4.StdOut;

public class BruteCollinearPoints {

    // implementation of other methods

    public static void main(String[] args) {
        // read the n points from a file
        In in = new In(args[0]);
        int n = in.readInt();
        Point[] points = new Point[n];
        for (int i = 0; i < n; i++) {
            int x = in.readInt();
            int y = in.readInt();
            points[i] = new Point(x, y);
        }

//         draw the points
        StdDraw.setXscale(0, 32768);
        StdDraw.setYscale(0, 32768);
        StdDraw.setPenColor(StdDraw.RED);
        StdDraw.setPenRadius(0.01);
        for (Point p : points) {
            p.draw();

        }
        StdDraw.show();

        // print and draw the line segments
        BruteCollinearPoints collinear = new BruteCollinearPoints(points);
        for (LineSegment segment : collinear.segments()) {
            StdOut.println(segment);
            segment.draw();
        }
        StdDraw.show();
    }
}

For more details please refer assignment's page ( link ).

Also, CLASSPATH environment variable should include C:\\Users\\Jen\\Desktop\\princeton-algorithms\\collinear directory as well as algs4.jar archive.

CLASSPATH: C:\\Users\\Jen\\algs4\\algs4.jar;C:\\Users\\Jen\\Desktop\\princeton-algorithms\\collinear

Execute javac-algs4 *.java from C:\\Users\\Jen\\Desktop\\princeton-algorithms\\collinear directory to compile sources to binaries.

Execute java-algs4 BruteCollinearPoints input8.txt to run main method of BruteCollinearPoints class.