Google map API：查询地理位置和经纬度信息示例
这两天工作需要调用到Google API，所以查询官方文档了解了一下，发现很方便。
注册Google Key
1、首先需要注册一个Google Cloud 账号。
2、创建一个项目。
具体步骤不记得了，之后再补，之前碰巧有注册过账号，就可以直接用。项目任意命名就可以。
查看官方地图API文档
Google全部API的地址：https://cloud.google.com/maps-platform/?hl=zh-CN
Google地图API的地址：https://cloud.google.com/maps-platform/?apis=maps
1、点击使用入门。
2、之前已经创建过project，直接选择一个即可
3、接着会给一个Google Key，快速复制下来保存即可。这个Key会在后面调用API的时候用到。
API调用说明
首先还是参考自官方文档：https://developers.google.com/maps/documentation/geocoding/start
适用平台：
可以作为Google Maps API的一部分使用，也可以与Java、Python、Go等客户端使用，还可以在服务端使用
官方原话：This service is also available as part of the client-side Google Maps JavaScript API, or for server-side use with the Java Client, Python Client, Go Client and Node.js Client for Google Maps Services.
用途：
Geocoding：将地址转换为地理坐标即经纬度的过程。
Reverse geocoding ：将地理坐标转换为实际地址的过程。
Geocoding API也可以通过place ID查找地理位置。
官方原话：
Geocoding is the process of converting addresses (like a street address) into geographic coordinates (like latitude and longitude), which you can use to place markers on a map, or position the map.
Reverse geocoding is the process of converting geographic coordinates into a human-readable address.
You can also use the Geocoding API to find the address for a given place ID.
API简单调用示例
1、通过HTTP调用查询地理信息接口：会返回json格式的详细地理信息，比如国家Country、省State、城市City、纬度lat、经度lng
https://maps.googleapis.com/maps/api/geocode/json
示例：浏览器直接请求该接口查询1600 Amphitheatre Parkway, Mountain View, CA这个地址（其实是Google美国的地址）的详细信息，注意YOUR_API_KEY需要替换为自己的Google Key
https://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&key=YOUR_API_KEY
返回的数据为：
{
"results" : [
{
"address_components" : [
{
"long_name" : "1600",
"short_name" : "1600",
"types" : [ "street_number" ]
},
{
"long_name" : "Amphitheatre Parkway",
"short_name" : "Amphitheatre Pkwy",
"types" : [ "route" ]
},
{
"long_name" : "Mountain View",
"short_name" : "Mountain View",
"types" : [ "locality", "political" ]
},
{
"long_name" : "Santa Clara County",
"short_name" : "Santa Clara County",
"types" : [ "administrative_area_level_2", "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" ]
}
],
"formatted_address" : "1600 Amphitheatre Pkwy, Mountain View, CA 94043, USA",
"geometry" : {
"location" : {
"lat" : 37.4267861,
"lng" : -122.0806032
},
"location_type" : "ROOFTOP",
"viewport" : {
"northeast" : {
"lat" : 37.4281350802915,
"lng" : -122.0792542197085
},
"southwest" : {
"lat" : 37.4254371197085,
"lng" : -122.0819521802915
}
}
},
"place_id" : "ChIJtYuu0V25j4ARwu5e4wwRYgE",
"plus_code" : {
"compound_code" : "CWC8+R3 Mountain View, California, United States",
"global_code" : "849VCWC8+R3"
},
"types" : [ "street_address" ]
}
],
"status" : "OK"
}其中：
“geometry”：经纬度
“address_components” ：按照等级描述了该位置的行政地理信息，
“formatted_address”：格式化好的地理信息。
假设一些原因导致无法访问到接口，也可以将域名https://maps.googleapis.com 改为 https://ditu.google.cn
2、通过HTTP调用查询地理信息接口：会返回json格式的详细地理信息，比如国家Country、省State、城市City、纬度lat、经度lng
https://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&key=YOUR_API_KEY
如果希望返回的语言不同，还可以加上参数&language=en
返回的数据为：
{
"plus_code" : {
"compound_code" : "P27Q+MC New York, NY, USA",
"global_code" : "87G8P27Q+MC"
},
"results" : [
{
"address_components" : [
{
"long_name" : "279",
"short_name" : "279",
"types" : [ "street_number" ]
},
{
"long_name" : "Bedford Avenue",
"short_name" : "Bedford Ave",
"types" : [ "route" ]
},
{
"long_name" : "Williamsburg",
"short_name" : "Williamsburg",
"types" : [ "neighborhood", "political" ]
},
{
"long_name" : "Brooklyn",
"short_name" : "Brooklyn",
"types" : [ "political", "sublocality", "sublocality_level_1" ]
},
{
"long_name" : "Kings County",
"short_name" : "Kings County",
"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" ]
}
],
"formatted_address" : "279 Bedford Ave, Brooklyn, NY 11211, USA",
"geometry" : {
"location" : {
"lat" : 40.7142484,
"lng" : -73.9614103
},
"location_type" : "ROOFTOP",
"viewport" : {
"northeast" : {
"lat" : 40.71559738029149,
"lng" : -73.9600613197085
},
"southwest" : {
"lat" : 40.71289941970849,
"lng" : -73.96275928029151
}
}
},
"place_id" : "ChIJT2x8Q2BZwokRpBu2jUzX3dE",
"plus_code" : {
"compound_code" : "P27Q+MC Brooklyn, New York, United States",
"global_code" : "87G8P27Q+MC"
},
"types" : [
"bakery",
"cafe",
"establishment",
"food",
"point_of_interest",
"store"
]
},
... Additional results truncated in this example[] ...
],
"status" : "OK"
}其中：
long_name/short_name：各种涉及到的位置的名称
types：对country、state、city这些的定义