百度地图之调用URL api接口实现周边搜索及计算球面两点间的距离

冷不防 2022-08-27 01:17 545阅读 0赞

1.通过关键字,中心点的经纬度,搜索半径来进行周边搜索,这个可以自己封装个类,主要是一个get请求,返回的数据既可以是json格式,也可以是xml格式,需要指定

2.封装一个HttpClientUtil类用于发送get或post请求,也可以在封装一层,在其他地方直接调用该方法,输入关键字,经纬度,搜索半径进行调用,这里使用了searchAround()这个方法名

3.需要用到的jar包下载地址:[http://download.csdn.net/detail/u013310075/7247879][http_download.csdn.net_detail_u013310075_7247879]

代码如下:

import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.net.URLEncoder;
    import java.util.List;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.NameValuePair;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.client.params.CookiePolicy;
    import org.apache.http.client.params.HttpClientParams;
    import org.apache.http.client.utils.URLEncodedUtils;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.apache.http.util.EntityUtils;
    
    @SuppressWarnings("deprecation")
    public class HttpClientUtil {
    
        /**
         * post 获取 rest 资源
         * 
         * @param url
         * @param name_value_pair
         * @return
         * @throws IOException
         */
        public static String doPost(String url, List<NameValuePair> nameValuePair) throws IOException {
            String body = "{}";
            @SuppressWarnings("resource")
    		DefaultHttpClient httpClient = new DefaultHttpClient();
            try {
                HttpPost httpost = new HttpPost(url);
                httpost.setEntity(new UrlEncodedFormEntity(nameValuePair, "UTF-8"));
                HttpResponse response = httpClient.execute(httpost);
                HttpEntity entity = response.getEntity();
                body = EntityUtils.toString(entity);
            } finally {
                httpClient.getConnectionManager().shutdown();
            }
            return body;
        }
    
        /**
         * get 获取 rest 资源
         * 
         * @param url
         * @return
         * @throws ClientProtocolException
         * @throws IOException
         */
        public static String doGet(String url) throws ClientProtocolException, IOException {
            String body = "{}";
            @SuppressWarnings("resource")
    		DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpClientParams.setCookiePolicy(httpClient.getParams(), CookiePolicy.BROWSER_COMPATIBILITY);
            try {
                HttpGet httpget = new HttpGet(url);
                HttpResponse response = httpClient.execute(httpget);
                HttpEntity entity = response.getEntity();
                body = EntityUtils.toString(entity);
            } finally {
                httpClient.getConnectionManager().shutdown();
            }
            return body;
        }
        
        public static String searchAround(String keyWord,double longitude,double latitude,long radius) throws ClientProtocolException, IOException {
        	String path = null;
    		try {
    			String keyWordEncoder = URLEncoder.encode(keyWord, "UTF-8");
    			//通过output指定返回值类型,可以是json也可以是xml
    			path = "http://api.map.baidu.com/place/search?query="+keyWordEncoder+"&location="+latitude+","+longitude+"&radius="+radius+"&output=json";
    			return doGet(path);
    		} catch (UnsupportedEncodingException e) {
    			e.printStackTrace();
    		}
    		return null;
        }
    
    }

2.封装一个BaiduMapUtil的类,用于计算球面两点间的距离,单位(米)

public class BaiduMapUtil {
    	 /** 
         * 计算两点之间距离 
         * @param start 
         * @param end 
         * @return 米 
         */  
        public static double getDistance(double longitude1,double latitude1, double longitude2,double latitude2){  
            double lat1= (Math.PI/180)*latitude1;  
            double lat2 = (Math.PI/180)*latitude2;  
              
            double lon1 = (Math.PI/180)*longitude1;  
            double lon2 = (Math.PI/180)*longitude2;  
              
            //地球半径  
            double R = 6371;  
              
            //两点间距离 km，如果想要米的话，结果*1000就可以了  
            double d =  Math.acos(Math.sin(lat1)*Math.sin(lat2)+Math.cos(lat1)*Math.cos(lat2)*Math.cos(lon2-lon1))*R;  
              
            return d*1000;  
        }  
    }

3.写一个测试类(HttpClientTest)进行测试,代码如下

public class HttpClientTest {
    	public static void main(String[] args) {
    		/**根据关键字及经纬度,搜索半径得到周边搜索的json数据**/
    		String baiduMapJson = null;
    		try {
    			baiduMapJson = HttpClientUtil.searchAround("银行",102.680412,25.030081,3000);
    		} catch (Exception e) {
    			e.printStackTrace();
    		} 
            System.out.println(baiduMapJson);
            /**根据经纬度获得两点间的距离**/
            double distance = BaiduMapUtil.getDistance(102.680412,25.030081, 102.681919,25.023);
            System.out.println(distance);
    	}
    }

[http_download.csdn.net_detail_u013310075_7247879]: http://download.csdn.net/detail/u013310075/7247879