http://maps.google.com/maps/api/geocode/output?parameters
where output may be either of the following values:
json (recommended) indicates output in JavaScript Object Notation (JSON)
xml indicates output as XML
Certain parameters are required while some are optional. As is standard in URLs, all parameters are separated using the ampersand (&) character. The list of parameters and their possible values are enumerated below.
The Geocoding Web Service defines map images using the following URL parameters:
address (required) — The address that you want to geocode.*
OR
latlng (required) — The textual latitude/longitude value for which you wish to obtain the closest, human-readable address.*
bounds (optional) — The bounding box of the viewport within which to bias geocode results more prominently. (For more information see Viewport Biasing below.)
region (optional) — The region code, specified as a ccTLD ("top-level domain") two-character value. (For more information see Region Biasing below.)
language (optional) — The language in which to return results. See the supported list of domain languages. Note that we often update supported languages so this list may not be exhaustive. If language is not supplied, the geocoder will attempt to use the native language of the domain from which the request is sent wherever possible.
sensor (required) — Indicates whether or not the geocoding request comes from a device with a location sensor. This value must be either true or false.
* Note: You may pass either an address or a latlng to lookup. (If you pass a latlng, the geocoder performs what is known as a reverse geocode. See Reverse Geocoding for more information.)
The bounds and region parameters will only influence, not fully restrict, results from the geocoder.
Geocoding Responses
Geocoding responses are returned in the format indicates by the output flag within the URL request's path.
JSON Output Formats
In this example, the Geocoding Service requests a json response for a query on "1600 Amphitheatre Parkway, Mountain View, CA":
http://maps.google.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true_or_false
We've left the sensor parameter in this example as a variable true_or_false to emphasize that you must set this value to either true or false explicitly.
The JSON returned by this request is shown below. Note that actual JSON may contain less whitespace. You should not make assumptions about the amount or format of whitespace between requests.
{
"status": "OK",
"results": [ {
"types": [ "street_address" ],
"formatted_address": "1600 Amphitheatre Pkwy, Mountain View, CA 94043, USA",
"address_components": [ {
"long_name": "1600",
"short_name": "1600",
"types": [ "street_number" ]
}, {
"long_name": "Amphitheatre Pkwy",
"short_name": "Amphitheatre Pkwy",
"types": [ "route" ]
}, {
"long_name": "Mountain View",
"short_name": "Mountain View",
"types": [ "locality", "political" ]
}, {
"long_name": "California",
"short_name": "CA",
"types": [ "administrative_area_level_1", "political" ]
}, {
"long_name": "United States",
"short_name": "US",
"types": [ "country", "political" ]
}, {
"long_name": "94043",
"short_name": "94043",
"types": [ "postal_code" ]
} ],
"geometry": {
"location": {
"lat": 37.4219720,
"lng": -122.0841430
},
"location_type": "ROOFTOP",
"viewport": {
"southwest": {
"lat": 37.4188244,
"lng": -122.0872906
},
"northeast": {
"lat": 37.4251196,
"lng": -122.0809954
}
}
}
} ]
}
Note that the JSON response contains two root elements:
"status" contains metadata on the request. See Status Codes below.
"results" contains an array of geocoded address information and geometry information.
Generally, only one entry in the "results" array is returned for address lookups, though the geocoder may return several results when address queries are ambiguous.
Note that these results generally need to be parsed if you wish to extract values from the results. Parsing JSON is relatively easy. See Parsing JSON for some recommended design patterns.
XML Output Formats
In this example, the Geocoding Service requests an xml response for the identical query shown above for "1600 Amphitheatre Parkway, Mountain View, CA":
http://maps.google.com/maps/api/geocode/xml?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true_or_false
The XML returned by this request is shown below.
Note that the XML response consists of a single
Zero of more
Note that this response is considerably longer than the JSON response. For that reason, we recommend that you use json as the preferred output flag unless your service requires xml for some reason. Additionally, processing XML trees requires some care, so that you reference proper nodes and elements. See Parsing XML with XPath for some recommended design patterns for output processing.
Status Codes
The "status" field within the Geocoding response object contains the status of the request, and may contain debugging information to help you track down why Geocoding is not working. The "status" field may contain the following values:
"OK" indicates that no errors occurred; the address was successfully parsed and at least one geocode was returned.
"ZERO_RESULTS" indicates that the geocode was successful but returned no results. This may occur if the geocode was passed a non-existent address or a latlng in a remote location.
"OVER_QUERY_LIMIT" indicates that you are over your quota.
"REQUEST_DENIED" indicates that your request was denied, generally because of lack of a sensor parameter.
"INVALID_REQUEST" generally indicates that the query (address or latlng) is missing.
Results
When the geocoder returns results, it places them within a (JSON) results array. Even if the geocoder returns no results (such as if the address doesn't exist) it still returns an empty results array. (XML responses consist of zero or more
A typical result is made up of the following fields:
The types[] array indicates the type of the returned result. This array contains a set of one or more tags identifying the type of feature returned in the result. For example, a geocode of "Chicago" returns "locality" which indicates that "Chicago" is a city, and also returns "political" which indicates it is a political entity.
formatted_address is a string containing the human-readable address of this location. Often this address is equivalent to the "postal address," which sometimes differs from country to country. (Note that some countries, such as the United Kingdom, do not allow distribution of true postal addresses due to licensing restrictions.) This address is generally composed of one or more address components. For example, the address "111 8th Avenue, New York, NY" contains separate address components for "111" (the street number, "8th Avenue" (the route), "New York" (the city) and "NY" (the US state). These address components contain additional information as noted below.
address_components[] is an array containing the separate address components, as explained above.
Each address_component typically contains:
types[] is an array indicating the type of the address component.
long_name is the full text description or name of the address component as returned by the Geocoder.
short_name is an abbreviated textual name for the address component, if available. For example, an address component for the state of Alaska may have a long_name of "Alaska" and a short_name of "AK" using the 2-letter postal abbreviation.
Note that address_components[] may contain more address components than noted within the formatted_address.
geometry contains the following information:
location contains the geocoded latitude,longitude value. For normal address lookups, this field is typically the most important.
location_type stores additional data about the specified location.
The following values are currently supported:
"ROOFTOP" indicates that the returned result is a precise geocode for which we have location information accurate down to street address precision.
"RANGE_INTERPOLATED" indicates that the returned result reflects an approximation (usually on a road) interpolated between two precise points (such as intersections). Interpolated results are generally returned when rooftop geocodes are unavailable for a street address.
"GEOMETRIC_CENTER" indicates that the returned result is the geometric center of a result such as a polyline (for example, a street) or polygon (region).
"APPROXIMATE" indicates that the returned result is approximate.
viewport contains the recommended viewport for displaying the returned result, specified as two latitude,longitude values defining the southwest and northeast corner of the viewport bounding box. Generally the viewport is used to frame a result when displaying it to a user.
bounds (optionally returned) stores the bounding box which can fully contain the returned result. Note that these bounds may not match the recommended viewport. (For example, San Francisco includes the Farallon islands, which are technically part of the city, but probably should not be returned in the viewport.)
As the exact format of an individual response to a Geocoding web service request is not guaranteed, you should never assume that elements are in absolute positions. (In particular, the number of address_components within a Geocoding web service response vary based on the address requested and can change over time.) Instead, you should parse the response and select appropriate values via expressions. See the Parsing Responses for more information.
Address Component Types
The types[] array within the returned result indicates the address type. These types may also be returned within address_components[] arrays to indicate the type of the particular address component. Addresses within the geocoder may have multiple types; the types may be considered "tags". For example, many cities are tagged with the political and locality type.
The following types are supported and returned by the HTTP Geocoder:
street_address indicates a precise street address.
route indicates a named route (such as "US 101").
intersection indicates a major intersection, usually of two major roads.
political indicates a political entity. Usually, this type indicates a polygon of some civil administration.
country indicates the national political entity, and is typically the highest order type returned by the Geocoder.
administrative_area_level_1 indicates a first-order civil entity below the country level. Within the United States, these administrative levels are states. Not all nations exhibit these administrative levels.
administrative_area_level_2 indicates a second-order civil entity below the country level. Within the United States, these administrative levels are counties. Not all nations exhibit these administrative levels.
administrative_area_level_3 indicates a third-order civil entity below the country level. This type indicates a minor civil division. Not all nations exhibit these administrative levels.
colloquial_area indicates a commonly-used alternative name for the entity.
locality indicates an incorporated city or town political entity.
sublocality indicates an first-order civil entity below a locality
neighborhood indicates a named neighborhood
premise indicates a named location, usually a building or collection of buildings with a common name
subpremise indicates a first-order entity below a named location, usually a singular building within a collection of buildings with a common name
postal_code indicates a postal code as used to address postal mail within the country.
natural_feature indicates a prominent natural feature.
airport indicates an airport.
park indicates a named park.
point_of_interest indicates a named point of interest. Typically, these "POI"s are prominent local entities that don't easily fit in another category such as "Empire State Building" or
"Statue of Liberty."
In addition to the above, address components may exhibit the following types:
post_box indicates a specific postal box.
street_number indicates the precise street number.
floor indicates the floor of a building address.
room indicates the room of a building address.
Reverse Geocoding (Address Lookup)
The term geocoding generally refers to translating a human-readable address into a location on a map. The process of doing the converse, translating a location on the map into a human-readable address, is known as reverse geocoding.
The Geocoding web service supports reverse geocoding directly using the latlng parameter. For example, the following query contains the latitude/longitude value for a location in Brooklyn:
http://maps.google.com/maps/api/geocode/json?latlng=40.714224,-73.961452&sensor=true_or_false
Note: Ensure that no space exists between the latitude and longitude values when passed in the latlng parameter.
This query returns the following result:
{
"status": "OK",
"results": [ {
"types": [ "street_address" ],
"formatted_address": "275-291 Bedford Ave, Brooklyn, NY 11211, USA",
"address_components": [ {
"long_name": "275-291",
"short_name": "275-291",
"types": [ "street_number" ]
}, {
"long_name": "Bedford Ave",
"short_name": "Bedford Ave",
"types": [ "route" ]
}, {
"long_name": "New York",
"short_name": "New York",
"types": [ "locality", "political" ]
}, {
"long_name": "Brooklyn",
"short_name": "Brooklyn",
"types": [ "administrative_area_level_3", "political" ]
}, {
"long_name": "Kings",
"short_name": "Kings",
"types": [ "administrative_area_level_2", "political" ]
}, {
"long_name": "New York",
"short_name": "NY",
"types": [ "administrative_area_level_1", "political" ]
}, {
"long_name": "United States",
"short_name": "US",
"types": [ "country", "political" ]
}, {
"long_name": "11211",
"short_name": "11211",
"types": [ "postal_code" ]
} ],
"geometry": {
"location": {
"lat": 40.7142298,
"lng": -73.9614669
},
"location_type": "RANGE_INTERPOLATED",
"viewport": {
"southwest": {
"lat": 40.7110822,
"lng": -73.9646145
},
"northeast": {
"lat": 40.7173774,
"lng": -73.9583193
}
}
}
},
NB: XML processing using java will be published on another post after further improvements.
This does not work!
ReplyDeleteI guess i should have made it clearer by separating the concerns;
ReplyDeletePaste the following in your browser and see for yourself:
http://maps.google.com/maps/api/geocode/xml?latlng=-4.0175,39.72&sensor=false