解析指南

Question

我可以使用经度和纬度从google检索数据，但不能使用directions属性。这就是我迄今所做的

public class MainActivity extends Activity {
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
        if (android.os.Build.VERSION.SDK_INT > 9) {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
    }
            try
            {
                String Lat=Double.toString(22.508507985602836);
                String Long=Double.toString(73.474991977022533);

                String Address = ReadAddressFromWebService(Lat,Long);
                Toast.makeText(this,Address, Toast.LENGTH_LONG).show();
            }

            catch(Exception e)
            {
                Log.e("error","Json parsing error :"+ e.toString());
                Toast.makeText(this,e.toString(), Toast.LENGTH_LONG).show();
            }
    }

    public String ReadAddressFromWebService(String latitude, String longitude) {
            String Address="";
            StringBuffer sb=new StringBuffer();
            sb.append("http://maps.googleapis.com/maps/api/geocode/json?latlng="+
              latitude +","+longitude +"&sensor=false");
                String url=sb.toString();
            HttpClient httpClient=new DefaultHttpClient();

            Log.i("","HTTP client created");
            String responseData="";
        try {
            HttpResponse response=httpClient.execute(new HttpGet(url));
            response.addHeader("Accept-Language", "it-IT");
            HttpEntity entity=response.getEntity();
            Log.i("", "HTTP Response arrived");

            BufferedReader bf=new BufferedReader(new
            InputStreamReader((entity.getContent()),"UTF-8"));
            String line="";
            Log.i("","Start buffre reading");

        while((line=bf.readLine())!=null){
            responseData=responseData+line;
        }

            JSONObject jsonObj = new JSONObject(responseData);

            JSONArray resultArry = jsonObj.getJSONArray("results");

            Address = resultArry.getJSONObject(0).getString("formatted_address").toString();

        } catch (Exception e) {
        // TODO Auto-generated catch block
            e.printStackTrace();
    }

    return Address;
    }
}

我试图以这样的方式更改StringBuffer：sb.append("http://maps.googleapis.com/maps/api/directions/json?origin="+ latitude +"&destination="+longitude +"&sensor=false");

但是我用来看结果的祝酒词没有显示任何东西..。为空，并得到一行JSONObject错误: Address = resultArry.getJSONObject(0).getString("formatted_address").toString();

所以，这就是我要解析的json：http://maps.googleapis.com/maps/api/directions/json?origin=vicenza&destination=costabissara&sensor=false

我会展示路线..。我当然改变了：

‘`JSONArray =jsonObj.getJSONArray(“结果”)；

        Address = resultArry.getJSONObject(0).getString("formatted_address").toString();`

至

‘`JSONArray =jsonObj.getJSONArray(“路由”)；

        Address = resultArry.getJSONObject(0).getString("legs").toString();`

但没有成功..。

Answer 1

我已经试过你的例子了，成功了。我唯一需要做的更改是，我没有将坐标传递给ReadAddressFromWebService，而是传递了源字符串和目标字符串：

String from = "vicenza";
String to = "costabissara";

String Address = ReadAddressFromWebService(from,to);

origin和destination使用的是位置名而不是坐标。