Java 2017 Code Sprint

The current plan is for the Java tribe to meet in Italy at the start of March. This page will allow us to plan the event.

Location

We will be hosted at the GeoSolutions offices in beautiful Tuscany for a week long sprint. Available seats are limited to 10 to 15!

Questions:

Who would be interested in joining as a participating?
Who would be interested in sponsoring? ;-)
Do you have any preferred week between say March 13 and end of March?

Participants

Please add your name and the projects you are planning to sprint and note the likehood of your attendance.

Participants
#	Participant	Country	Organization	Arrival	Departure	Project Work on	Notes	Attendance
1	Andrea Aime	Italy	GeoSolutions			CITE or REST API switch	Preference for CITE, I'm game for the REST API switch too	Local
2	Ian Turton	UK	Astun			CITE, Java 8 upgrade		Planning
3	Andrea Antonello	Italy	HydroloGIS			gvSIG and cross-project ideas	I have a strong preference for the end of March	Planning
4	Jody Garnett	Canada	Boundless			GeoServer and GeoTools	Enthusiastic about CITE and REST API work	Planning
5	Niels Charlier	Belgium	Scitus Development			GeoServer and GeoTools	Keen to do REST API work, MapBox seems interesting too.	Tentatively planning, possibly partially
6	Torben Barsballe	Canada	Boundless			REST API or CITE	Preference for REST API, would also be fine with CITE	Planning
7	Mike Pumphrey	USA	Boundless			Documentation	I'll help out with whatever you all decide on	Depends on what dates we decide
8	Kevin Smith	Canada	Boundless			GeoServer, GeoTools, and GeoWebCache	REST update, Language Update prep, library updates, deguavafication are all interesting	Planning
9	Devon Tucker	Canada	Boundless			GeoServer, GeoTools	REST update or CITE tests	Tentative/Planning
10	Nuno Oliveira	Portugal	GeoSolutions			GeoServer, GeoTools	REST update, CITE tests, Clustering, Language Update prep, library updates	Planning

GeoServer

The GeoServer team really benefited from geoserver code sprint 2016 and is eager to repeat the success.

GeoServer Plans (choose ONE of the following)

We are still at the planning stage so please let us know if a particular topic interests you or would be a deal breaker. The sprint does not have to be a single topic, if we can swarm a large beast good, but if someone wants to join and work on a side topic to leverage the presence of others, that’s good too.

CITE

The OGC Compliance Program provides the CITE tool for testing standards compliance. Our build process makes heavy use of this tool ... ensuring that each and every release of GeoServer correctly implements WMS, WFS, and WCS.

There are three problems with this:

We last updated our CITE build tool 2012 (so our testing is quite out of date).
Our geoserver.org website can only say we are a "compliant implementation", rather than a "certified implementation" of the WCS, WMS and WFS standards.
New services such as WPS and CSW are not "blackbox" tested.

The OGC provide the CITE Team Engine both as a web service and as an open source project that can be used to check a single instance of GeoServer. This is a little awkward as we would like to integrate these tests into our build server; as such our build server stands up a geoserver instance, performance the tests, and publishes the results here. These tests also require a database - and modify that database over the course of the tests (so our build server needs a PostGIS running).

Armed with a positive test result we can ask OSGeo to pay for OGC certification, allowing us to update our website. As an alternative to paying money the OGC allows open source projects to be listed as a "reference implementation" (providing an instance of the server is available online for potential clients to test against).

Rough planning:

Upgrade the test harness
Make sure the tests are still passing (probably they won’t),
Add new test that we are missing
- WFS 2.0,
- WCS 2.0
- CSW
- WMTS 1.0
- WPS 1.0,
- maybe GML and KML and GeoPackage
OGC Certification
- Submit required paperwork, and test results, update website
Reference Implementation
- Maybe stand up a reference server for OGC to use (if OSGeo or OGC provide hardware) with one test per workspace/virtual service?

REST API

The REST API Refresh focuses on migrating the module from Restlet to the more popular Spring MVC, fixing as many issues as we can, and documenting the result.

The REST API for GeoServer is popular, but not well maintained, collecting a large number of outstanding bugs. Many of these complain about functionality and lack of documentation. The large number of bugs (API called correctly but produced an error) may be producing more requests for documentation (developer assumed they called it incorrectly, and asks for improved documentation with an example that works).

Internally the REST API is written using an early java library called "restlet" (http://restlet.com/). There is a desire to migrate to spring rest api which is annotation driven and better supported. The risk in performing a migration to Spring MVC is introducing more bugs than are fixed. This is somewhat offset by having a larger pool of developers familiar with the codebase and the technologies used.

   /**
    * API endpoint to get details on a specific layer
    * @param wsName The workspace name
    * @param name The layer name
    * @param req The HTTP request
    * @return The layer, encoded as a JSON object
    */
   @RequestMapping(value="/{wsName}/{name:.+}", method = RequestMethod.GET)
   public @ResponseBody JSONObj get(@PathVariable String wsName, @PathVariable String name, HttpServletRequest req) {

Rough plan:

Create a rest-ng module (alongside existing rest, restconfig, importer-rest, ....)
- Module based on Spring MVC - see simple PrjController.java example and complex LayerController.java example.
- Set up converters/encoders for resources
Migrate restconfig functionality
Migrate importer-rest functionality
resource-rest-api
rest-upload
Audit functionality against GUI
- shortlist missing functionality for proposal and implementation (examples recalculate feature type columns, rest layer bounds from SRS boudns, ...)
Test cases should remain unchanged
Documentation
- Set up documentation team operating concurrently, capturing each resource as it is completed
- Go for a resource description, json and xml example, example of each kind of request (GET, PUT, POST, DELETE) as appropriate. See mapbox example and boundless example.
- Consider auto generating example output from test case (see spring-restdocs)

This activity will require quite a bit of people (all hands on deck).

Reference:

Searching for REST
Searching for Module (not always properly assigned)

Mapbox Style

The GeoServer application can be extended to work with multiple styling languages (SLD, CSS, YSLD). Mapbox has recently defined an open standard for drawing vector tiles that has been picked up by not only their own software but by the OpenLayers team. Initial investigation into this standard shows that it is a "whole" map standard similar to "sld" describing both the layers that make up the map, and the symbology used to represent them visually.

While some features (3d extrusions, camera and lighting angle) are not suitable for use by GeoServer the rest of it looks quite fun.

References:

https://www.mapbox.com/mapbox-gl-style-spec/

https://boundlessgeo.com/2017/01/using-mapbox-style-objects-open-layers/

Rough planning:

Focus on styling a single layer using a mapbox style
- Requires a parser for mapbox style capable of producing the internal geotools style objects; package as a geotools community module.
- Setup geoserver extension and integration for new style format
Whole map styling (optional)
- LayerGroup defines both an order of layers, and the style associated with each layer - this information can be defined from a single mapbox style
- (Optional) Consider offering SLD the same ability to define a LayerGroup

Library upgrades

Last year's sprint was devoted to updating a key library and required all hands on deck to help make the transition a smooth one. Ideally we would like to stay on top of library upgrades; however often a change to one has a cascade effect as we need to update (and test) each library in turn.

Libraries
Library	Version	Latest	Description
Wicket	7.1.0	7.6.0	user interface (note 8.x milestones being released presently)
hsql	2.3.0	2.3.4	java database
h2	1.1.119	1.3.176	java database (1.4.x beta currently available)
commons-dbcp	1.4	2.2	database connection pool
commons-beanutils	1.9.2	1.9.3	java bean utility library
commons-collections	3.2.2	java collection classes
guava	17.0	21.0	java collection classes and more
log4j	1.2.12	2.7	supports java 8 lambda, consider migrating to yaml/json config?
(and much more)

Note:

We may wish to migrate from guava to java 8 and commons collections; as guava often produces conflicts for downstream projects

GeoTools

GeoTools Plans

The GeoTools codebase has a number of smaller of ideas that may of be of interest to volunteers:

JDK 9 + maybe JDK 8 updates in the code base (like stream ready support for feature collection, where we can use lambda for profit)
JDK 9 replacement for plugin system (service registry) is required

The above ideas may also be suitable to anyone attending remotely who like the focus and support of a dedicated code sprint block on the calendar.

Gold	$1000 USD	€950 EUR
Silver	$500 USD	€470 EUR
Bronze	$250 USD	€235 EUR
Beer	In-kind contributions are graciously accepted

Java 2017 Code Sprint

Contents

Location

Participants

Sponsors

How to Sponsor

Sponsorship Outreach

OSGeo Funding Request