I recommend using the awesome requests library:

import requests

url = 'http://maps.googleapis.com/maps/api/directions/json'

params = dict(
    origin='Chicago,IL',
    destination='Los+Angeles,CA',
    waypoints='Joplin,MO|Oklahoma+City,OK',
    sensor='false'
)

resp = requests.get(url=url, params=params)
data = resp.json() # Check the JSON Response Content documentation below

JSON Response Content: https://requests.readthedocs.io/en/master/user/quickstart/#json-response-content

Use json objects. Do something like that. Don't write json by hand, you could easily do a mistake.

public JSON() throws JSONException
{
    JSONArray locArr=new JSONArray();
    locArr.put(createLatLng(40.900799, 8.606102));
    locArr.put(createLatLng(42.900799, 9.606102));
    JSONObject main=new JSONObject();
    main.put("locations", locArr);
    Log.d("JSON",main.toString());      
}


public JSONObject createLatLng(double lat, double lng) throws JSONException
{
    JSONObject latLng=new JSONObject();
    latLng.put("lat",lat);
    latLng.put("lon",lng);
    JSONObject latLngWrap=new JSONObject();
    latLngWrap.put("latLng",latLng);
    return latLngWrap;
}

Starting with Requests version 2.4.2, you can use the json= parameter (which takes a dictionary) instead of data= (which takes a string) in the call:

>>> import requests
>>> r = requests.post('http://httpbin.org/post', json={"key": "value"})
>>> r.status_code
200
>>> r.json()
{'args': {},
 'data': '{"key": "value"}',
 'files': {},
 'form': {},
 'headers': {'Accept': '*/*',
             'Accept-Encoding': 'gzip, deflate',
             'Connection': 'close',
             'Content-Length': '16',
             'Content-Type': 'application/json',
             'Host': 'httpbin.org',
             'User-Agent': 'python-requests/2.4.3 CPython/3.4.0',
             'X-Request-Id': 'xx-xx-xx'},
 'json': {'key': 'value'},
 'origin': 'x.x.x.x',
 'url': 'http://httpbin.org/post'}