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why? geo server is a next level template for vangav backend where database and geo services utility are used

geo server

• geo server service is generated using vangav backend

prerequisite

• vangav backend tutorials

functionality

• transforms geo coordinates (latitude and longitude) into reverse geo code and geo hash
• it also offers getting top queried continents and countries

overview

• this service is based on vangav backend's geo server template
• this service has the 90+% of the vangav backend's generated code + the 10-% of the logic code needed to complete the service

try this service

1. for first timers - follow the steps in the system requirements tutorial
2. for first timers - follow the steps in the workspace initialization tutorial
3. download this vos_geo_server.zip project (from the green clone or download button up there) inside the workspace directory created previously (my_services) and unzip it
4. rename unzipped vos_geo_server-master to vos_geo_server
5. in the terminal cd to vos_geo_server/cassandra/cql/
6. execute ./_start_cassandra.sh to start cassandra
7. cd to vos_geo_server/cassandra/cql/drop_and_create/
8. execute the command ./_execute_cql.sh gs_top_dev.cql to initialize the service's database tables
9. cd to vos_geo_server
10. start the service: ./_run.sh
11. from your prefered client (we recommned postman) start trying the service; refer to the features and service references sections for reference

• at the end to stop the service: press control + d in the terminal session where the service was started in (10)
• to stop cassandra: execute ps auwx | grep cassandra to get cassandra's (pid) then kill -9 (pid) to stop cassandra

eclipse

• follow the following steps to import the downloaded backend service in eclipse

1. cd to the service's directory and execute the ./_eclipsify.sh script
2. file > import > general > existing projects into workspace > next > set "select root directory" to my_services > under projects make sure that vos_calculate_sum is selected > finish
3. double check the java version used for compiling the project: right click the project > properties > java compiler > enable project specific settings > compiler compliance level > 1.7 or 1.8

covered topics

• generate a service with multi-entry-point api
• generate a database
• use the geo services utility

features

controller(s)	feature
reverse geo code	transforms request's latitude and longitude into reverse geo code (continent, country, city, ...) and geo hash
top continents and top countries	returns the top queried continents and countries

service references

reference	explanation
routes	api routes
reverse_geo_coding	reverse geo coding data
controllers.json	api request/response's elements
gs_top.keyspace	gs_top is the keysapce for all the tables keeping track of the most queried continents and countries
Global.java	reverse geo coding initialization
common	handles common operations like initializing the continents/countries names index
controllers	api implementation
gs_top	gs_top cassandra's keyspace client

change log

• this section lists the 10-% code added after vangav backend generated 90+% of the code

file/dir	change
conf/data	added reverse geo coding data from vangav backend's data
Global.java	added reverse geo coding initialization in beforeStart method
common	contains common operations like initializing the continents/countries names index
controllers	added the implementation of request processing logic under controller_name/HandlerControllerName.java classes and nested response json structures under controller_name/response_json packages

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