Question

我有一个java项目，我需要从地图中手动指定一个地方的纬度和经度。我实际上是使用此代码来获取使用地址的经度和纬度：

public class LongLatService {

    private static final String GEOCODE_REQUEST_URL = "http://maps.googleapis.com/maps/api/geocode/xml?sensor=false&";
    private static HttpClient httpClient = new HttpClient(new MultiThreadedHttpConnectionManager());

    public static void main(String[] args) throws Exception {
        LongLatService tDirectionService = new LongLatService();
        tDirectionService.getLongitudeLatitude("Rue Delangle, 58210 Varzy, France");
    }

    public void getLongitudeLatitude(String address) {
        try {
            StringBuilder urlBuilder = new StringBuilder(GEOCODE_REQUEST_URL);
            if (StringUtils.isNotBlank(address)) {
                urlBuilder.append("&address=").append(URLEncoder.encode(address, "UTF-8"));
            }

            final GetMethod getMethod = new GetMethod(urlBuilder.toString());
            try {
                httpClient.executeMethod(getMethod);
                Reader reader = new InputStreamReader(getMethod.getResponseBodyAsStream(), getMethod.getResponseCharSet());

                int data = reader.read();
                char[] buffer = new char[1024];
                Writer writer = new StringWriter();
                while ((data = reader.read(buffer)) != -1) {
                        writer.write(buffer, 0, data);
                }

                String result = writer.toString();
                System.out.println(result.toString());

                DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                DocumentBuilder db = dbf.newDocumentBuilder();
                InputSource is = new InputSource();
                is.setCharacterStream(new StringReader("<"+writer.toString().trim()));
                Document doc = db.parse(is);

                String strLatitude = getXpathValue(doc, "//GeocodeResponse/result/geometry/location/lat/text()");
                System.out.println("Latitude:" + strLatitude);

                String strLongtitude = getXpathValue(doc,"//GeocodeResponse/result/geometry/location/lng/text()");
                System.out.println("Longitude:" + strLongtitude);


            } finally {
                getMethod.releaseConnection();
            }
        } catch (Exception e) {
             e.printStackTrace();
        }
    }

    private String getXpathValue(Document doc, String strXpath) throws XPathExpressionException {
        XPath xPath = XPathFactory.newInstance().newXPath();
        XPathExpression expr = xPath.compile(strXpath);
        String resultData = null;
        Object result4 = expr.evaluate(doc, XPathConstants.NODESET);
        NodeList nodes = (NodeList) result4;
        for (int i = 0; i < nodes.getLength(); i++) {
            resultData = nodes.item(i).getNodeValue();
        }
        return resultData;
    }

}

但我希望从地图中获取经度和经度并在其他类中使用它们。

Answer 1

我建议您使用Java Client for Google Maps Services来实现此目的。它是Google为全球Java开发人员开发的一个库，用于使用各种Google Map功能，如Geocoding，Direction API，Distance Matrix API等。在您的情况下，您可能正在使用Geocode API返回指定地址的LatLng 。您需要在项目中集成此库（可以与Maven和Gradle一起使用），然后只需几行代码即可获得通过Google地图传递的地址的纬度和经度。

以下是您需要为Geocode API使用的代码：

GeoApiContext context = new GeoApiContext().setApiKey("AIza...");
GeocodingResult[] results =  GeocodingApi.geocode(context,
    "1600 Amphitheatre Parkway Mountain View, CA 94043").await();
System.out.println(results[0].formattedAddress);

如果您不想使用此库并编写自己的代码，可以参考this project中的代码示例。

希望这有助于!!

如何从java中的地图获取经度和纬度

1 个答案: