README.md

Overview

The Geofinder application leverages DSE Search's geospatial, type-ahead, and facet query capabilities to provide the easy-to-use UI end users expect. As new POI data is added to the cluster, it will be indexed immediately and be searchable as soon as it is ingested.

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Assumptions

DSE running, and already loaded the sample data into DSE that is backed by DSE Search.

• Java 8 installed
• maven

build:

git clone https://github.com/payamp/geofinder-api.git

mvn clean package

run:

usage: java -jar geofinder-api.jar
 -h,--hostname <arg>   cassandra host (required)
 -p,--password <arg>   Cassandra user password
 -s,--ssl              Use SSL, expects a truststore.jks file to be in
                       current directory
 -u,--user <arg>       Cassandra username

##Connecting app to DSE

SSL with authentication enabled example:

java -Djavax.net.ssl.trustStore=/path/to/client.truststore -Djavax.net.ssl.trustStorePassword=password -jar target/geofinder-api.jar -h 192.168.1.190 -u cassandra -p ChangeMe123 -ssl

If you installed using OpsCenter LCM, you will find the truststore here:

/etc/dse/keystores/client.truststore

using localhost without auth or SSL:

java -jar target/geofinder-api.jar -h localhost

User interface

The web app is exposed on port 9000

If you are running this from assethub, you will need to point your web browser at:

http://node0:9000/

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JSON Endpoints

Name Suggest

GET /api/name-suggest?name=string&sort=sortfield (asc desc)

URL Parameters:

Field	Description	Required	Example
name	the place name you want to search	YES
sort	The field you want to sort on	NO	"population desc" or "date asc"

Sample response

{
  "names": [
    "Chalgomchin",
    "Chichali Karam",
    "Chichali-e Seh",
    "Park-e Jangali-ye Chitgar",
    "Qanchi Gol",
    "Kuh-e Saghalchi",
    "Chin Parch",
    "Ilkhchi Kumeh",
    "Ichin",
    "Chinam Dahaneh",
    "Parchi Kola",
    "Shilat Chikrud",
    "Kuh-e Qal`ehchi",
    "Garachi",
    "Kuh-e Lak Chir",
    "Kuh-e Chidar",
    "Chir-e `Olya",
    "Chichuran",
    "Hajjiabad-e Okhtachi",
    "Alichin",
    "Chianeh",
    "Baleqchi",
    "Qomchian",
    "Eynehchi",
    "Turchi",
    "Kuh-e Chia",
    "Kuh-e Nochirya",
    "Kuh-e Tofangchian",
    "Pasha Chiftlik",
    "Pano Chiftlik",
    "Chai Chill",
    "Kachiones",
    "Chchinnokefalos",
    "Laxia tou Vachioti",
    "Kokkinorachi",
    "Chchinnomoutti",
    "Archistratigos",
    "Kuh-e Cheraghchi",
    "Kuh-e Kachi",
    "Kalateh-ye Chikal",
    "Kuh-e Chidandar",
    "Saqarchin",
    "Chiftlikoudhkia",
    "Kochinoyia",
    "Kochinoin",
    "Agios Vichianos",
    "Agios Tychikos",
    "Chistron Vounon",
    "Uqchi Kuchek",
    "Hivehchi-ye Bala"
  ],
  "query": "SELECT name from geonames.locations where solr_query = '{ \"q\":\"*:*\", \"fq\":\"name_lowercase:*chi*\"}' LIMIT 50"
}

Geo Contextual suggest

For example:

• Things Near me

GET /api/geo-name-suggest

URL Parameters:

Field	Description	Required	Default	min / max
name	the string you want to search	YES	N/A
lat	Latitude	YES	N/A	-90.0 / 90.0
lng	Longitude	YES	N/A	-180.0 / 180.0
r	The radius of the search in (km)	NO	5.0	1.0 / 20.0

Faceting using a geospatial filter query

Given a map extent, what category, and subcategory of POIs are available.

In solr you can filter on an arbitrary rectangle by using the search geo:[45,-94 TO 46,-93] searching for a bounding.

The order of the query is [lower-left TO upper-right], and the order is lat, lng.

GET /api/geo-facet-category?parameters

URL Parameters:

Field	Description	Required	min / max
lllat	Lower Left Latitude	YES	-90.0 / 90.0
lllng	Lower Left Longitude	YES	-180.0 / 180.0
urlat	Upper Right Latitude	YES	-90.0 / 90.0
urlng	Upper Right Longitude	YES	-180.0 / 180.0

GET /api/geo-facet-category-subcategory?parameters

URL Parameters:

Field	Description	Required	min / max
lllat	Lower Left Latitude	YES	-90.0 / 90.0
lllng	Lower Left Longitude	YES	-180.0 / 180.0
urlat	Upper Right Latitude	YES	-90.0 / 90.0
urlng	Upper Right Longitude	YES	-180.0 / 180.0

Searching for a particular category or subcategory of POI within a map extent.

GET /api/geo-bbox-filter-on-category?parameters

Field	Description	Required	min / max
category	Category	YES	N/A
subcategory	Subcategory	NO	N/A
num_records	Number of records (default 20)	NO
lllat	Lower Left Latitude	YES	-90.0 / 90.0
lllng	Lower Left Longitude	YES	-180.0 / 180.0
urlat	Upper Right Latitude	YES	-90.0 / 90.0
urlng	Upper Right Longitude	YES	-180.0 / 180.0

###sample response (truncated):

{
  "category,subcategory": [
    {
      "field": "category",
      "value": "Airline",
      "count": 116,
      "pivot": [
        {
          "field": "subcategory",
          "value": "",
          "count": 116
        }
      ]
    },
    {
      "field": "category",
      "value": "Airport",
      "count": 23,
      "pivot": [
        {
          "field": "subcategory",
          "value": "",
          "count": 23
        }
      ]
    }
  ]
}

Reference:

calculation on converting how many degrees will be lat lon info

theta = latitude;
let one_deg_lon_in_km = 111.13295 - 0.55982 * Math.cos(2 * theta) + 0.00117 * Math.cos(4 * theta);