JAVA Polygon 在配送区域超区校验的实践

摘要：业务背景物流同城配送，在用户下单的时候会进行配送超区校验，前端会将用户的定位传入后台服务，后台服务针对商家的自定义配送区域通过地图控件拖拽出来的不规则图形进行校验。

物流同城配送，在用户下单的时候会进行配送超区校验，前端会将用户的定位传入后台服务，后台服务针对商家的自定义配送区域（通过地图控件拖拽出来的不规则图形）进行校验。

利用java se工具类来做 java.awt.Polygon

api地址： https://docs.oracle.com/javas...

使用到的api主要有：

public Polygon(int[] xpoints,int[] ypoints,int npoints)
Parameters:
xpoints - an array of X coordinates  所有点的x坐标
ypoints - an array of Y coordinates  所有点的y坐标
npoints - the total number of points in the Polygon 总共的点数
scene:
把商家通过地图拖拽的多边形各点传入进来，实例化Polygon对象
public boolean contains(double x,double y)
Parameters:
x - the specified X coordinate to be tested x坐标  
y - the specified Y coordinate to be tested y坐标
scene:
获取用户当前定位的经纬度，作为x,y坐标系传入进行判断

   /**
     * 用例描述：测试场景 多边形为矩形 判断点是否在范围内
     *
     *
     * @since  2016-12-06 by 青芒
     */
    @Test
    public void test_rec_ContainsPoint(){
        try {
            int[] xpoints = {1,1,5,5};
            int[] ypoints = {1,5,5,1};
            Polygon polygon = new Polygon(xpoints, ypoints,4);

            boolean contains;

            Point p = new Point(2,2);
            contains = polygon.contains(p);
            Assert.assertTrue(contains);

            contains = polygon.contains(2, 2);
            Assert.assertTrue(contains);

            contains = polygon.contains(1, 4);
            Assert.assertTrue(contains);

            contains = polygon.contains(2, 2);
            Assert.assertTrue(contains);

            contains = polygon.contains(2.5, 2.5);
            Assert.assertTrue(contains);
        } catch (Exception e) {
            Assert.fail();
        }
    }

   /**
     * 用例描述：测试场景 多边形为矩形 判断矩形是否在范围内
     *
     *
     * @since  2016-12-06 by 青芒
     */
    @Test
    public void test_rec_ContainsRectangle(){
        try {
            int[] xpoints = {1,1,5,5};
            int[] ypoints = {1,5,5,1};
            Polygon polygon = new Polygon(xpoints, ypoints,4);

            Rectangle2D rectangle = new Rectangle(2,2,1,1);
            boolean contains = polygon.contains(rectangle);
            Assert.assertTrue(contains);
        } catch (Exception e) {
            Assert.fail();
        }
    }

   /**
     * 用例描述：测试场景 不规则多边形 包含点
     *
     *
     * @since  2016-12-06 by 青芒
     */
    @Test
    public void test_polygon_ContainsPoint(){
        try {
            int[] xpoints = {1,2,4,1,2};
            int[] ypoints = {3,4,3,3,2};
            Polygon polygon = new Polygon(xpoints, ypoints,5);
            boolean contains = polygon.contains(3, 3 );
            Assert.assertTrue(contains);

            contains = polygon.contains(2, 1);
            Assert.assertFalse(contains);
        } catch (Exception e) {
            Assert.fail();
        }
    }

    /**
     * 用例描述：测试场景 交叉多边形 包含点
     *
     *
     * @since  2016-12-06 by 青芒
     */
    @Test
    public void test_crossing_ContainsPoint(){
        try {
            int[] xpoints = {1,2,1,3,3};
            int[] ypoints = {1,2,3,3,1};
            Polygon polygon = new Polygon(xpoints, ypoints,5);
            boolean contains = polygon.contains(2, 2 );
            Assert.assertTrue(contains);

            contains = polygon.contains(2, 1 );
            Assert.assertTrue(contains);

            contains = polygon.contains(2, 1.5);
            Assert.assertTrue(contains);

            contains = polygon.contains(2.5, 2.5 );
            Assert.assertTrue(contains);

            //多边形外围
            contains = polygon.contains(0, 1);
            Assert.assertFalse(contains);

            contains = polygon.contains(1, 2);
            Assert.assertFalse(contains);

            contains = polygon.contains(3, 2);
            Assert.assertFalse(contains);
        } catch (Exception e) {
            Assert.fail();
        }
    }

至此对于该超区校验场景的实践已经介绍完毕，使用起来也不难，主要是让大家知道通过javase 的awt类也是可以容易实现的。