GeoSpatial Techno is a startup focused on geospatial information that is providing e-learning courses to enhance the knowledge of geospatial information users, students, and other startups. The main approach of this startup is providing quality, valid specialized training in the field of geospatial information.

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Binary Comparison Operators in GeoServer Filters

In this session, we want to talk about the various types of filters, with a particular focus on “Binary comparison operators in GeoServer” comprehensively. If you want to access the complete tutorial, click on the link.

Introduction

Filtering allows the selection of features that satisfy a specific set of conditions. Filters can be used in several contexts in GeoServer:

• In WMS requests, select which features should be displayed on a map
• In WFS requests, specify the features to be returned
• In SLD documents, apply different symbolizations to features on a thematic map

Note. This video was recorded on GeoServer 2.22.4, which is not the most up-to-date version. Currently, versions 2.24.x and 2.25.x are supported. To ensure you have the latest release, please visit this link and avoid using older versions of GeoServer.

Supported filter languages

Data filtering in GeoServer follows the OGC Filter Encoding Specification, which provides a standard XML schema for encoding spatial, attribute, and temporal filters in GIS. This allows for customized queries to retrieve specific data from databases and web services while ensuring interoperability among GIS applications. GeoServer supports filters in both Filter Encoding Language and Common Query Language.

Filter Encoding Language

The Filter Encoding language, defined by OGC standards, utilizes an XML-based syntax to select specific features, similar to the “WHERE” clause in SQL. A filter consists of a condition formed by Predicate elements and Logical operators, employing comparison and spatial operators to evaluate relationships between feature properties. In this session, we will explore various types of binary comparison operators, while the next sessions will cover spatial operators.

Common Query Language

Common Query Language (CQL) is a Text-based language used in GeoServer for constructing filters and queries on geospatial data. It provides flexible and powerful options for filtering and retrieving specific subsets of data from GeoServer layers. In the upcoming sessions, we will dive into a detailed exploration of CQL/ECQL, covering its various operations and practical usage.

Comparison operators

These operators are part of Filter Encoding operators and are used in attribute-based queries to filter and retrieve specific features or data, based on their non-spatial attributes. The comparison operators include: binary comparison operators and value comparison operators.

The binary comparison operators are:

• PropertyIsEqualTo
• PropertyIsNotEqualTo
• PropertyIsLessThan
• PropertyIsLessThanOrEqualTo
• PropertyIsGreaterThan
• PropertyIsGreaterThanOrEqualTo

These operators contain two filter expressions to be compared. The first operand is often a <PropertyName>, but both operands may be any expression, function or literal value. Binary comparison operator elements may include an optional matchCase attribute, with the true or false value. The default value is true, but the comparisons do not check the case if the attribute has a false value.

Note. String comparison operators are case-sensitive.

PropertyIsEqualTo

PropertyIsNotEqualTo is a common type of filter used in GeoServer, which allows you to retrieve features from a data source based on the values of one or more properties. As an example of using this filter in WFS getFeature request:

• Navigate to the Demos page, then select Demo requests.
• From the Request section, select the WFS_getFeature1.0.xml request.
• The address will be filled in automatically, in the URL section.

Use the following block codes to replace line 26:

<PropertyIsEqualTo>
  <PropertyName>STATE_NAME</PropertyName>
  <Literal>Delaware</Literal>
</PropertyIsEqualTo>	

• Now, we will explain some elements:
  • The first fifteen lines include explanations in the form of comments.
  • Line 16 describes the XML version and the GetFeature operation of the WFS service being used.
  • Line 17 specifies the default output format for the WFS service as “gml2.” Additionally, GeoServer supports several other commonly used formats such as “gml3, shapefile, geojson, and csv.”
  • Lines 18 to 23 define the start of the XML request and declare the namespaces used in the request.
  • Line 24 specifies the type name of the feature to be queried. In this case, it requests features of the “topp:states”.
  • Lines 25 to 30 define the filter criteria for the query. On these lines, we use the PropertyIsEqualTo filter, to retrieve all features where the state name attribute is equal to Delaware.

• Press the Submit button to see the implemented changes.

• Note. For GeoServer 2.25.2 the Demo Request page has been improved to show response Headers, and provide the option to pretty print XML output.

PropertyIsNotEqualTo

PropertyIsNotEqualTo is another common type of filter used in GeoServer, which allows you to retrieve features from a data source based on properties that don’t match a specified value. As an example of using this filter in a WFS getFeature request, use the following block codes to replace lines 26 to 29:

<PropertyIsNotEqualTo matchCase="false">
  <PropertyName>STATE_NAME</PropertyName>
  <Literal>delAwarE</Literal>
</PropertyIsNotEqualTo>

Note. The matchCase attribute in WFS_getFeature 1.1 and 2.0 versions, can be set to “false” to specify a case-insensitive comparison.

Press the Submit button.

In this example, we used the <PropertyIsNotEqualTo> filter to retrieve all features where the STATE_NAME attribute, is not equal to Delaware.

PropertyIsLessThan

The PropertyIsLessThan filter is used to filter features, based on a comparison of a numeric property with a given value. It returns all features where the specified property is less than the specified value.

An example of using this filter in a WFS getFeature request is:

outputFormat="shape-zip"
<wfs:Query typeName="topp:states">
    <wfs:PropertyName>topp:STATE_NAME</wfs:PropertyName> 
    <wfs:PropertyName>topp:LAND_KM</wfs:PropertyName>
<ogc:Filter>
  <PropertyIsLessThan>
    <PropertyName>STATE_FIPS</PropertyName>
    <Literal>18</Literal>
  </PropertyIsLessThan>
</ogc:Filter>

Press the Submit button.

In this example, we used the <PropertyIsLessThan> filter to get all features in a shapefile format where the value of the STATE_FIPS attribute is less than 18. The query only retrieves the STATE_NAME and LAND_KM fields, instead of all the attributes.

In this session, we took a brief journey through the various types of filters, with a particular focus on “Binary comparison operators in GeoServer”. If you want to access the complete tutorial, simply click on the link.

GeoServer is updating our communication channels!

We know people do not like signing up for mailing lists, Twitter has been Xed out, and it is time to move on.

GeoServer User Forum

Welcome to the GeoServer User forum:

• This forum is open to the public, we are pleased to meet you and hope you enjoy using GeoServer.
• Hosted by Open Source Geospatial Foundation
• All project communication including this forum are subject to our code of conduct
• This is one of many options for community support and communication.

Sign in

Taking part is easy (sign-in with credentials you already have):

1. Login to discourse.osgeo.org:

   • Login “with LDAP” to use your OSGeo UserID (also used for other osgeo services).

     The button appears greyed out, but this is only poor styling choice. The button is enabled and works.

   • Use “Log in with GitHub” to use GitHub credentials.

   • More options are added over time.

   

2. You may also use “Sign Up” if you want to create an account just for use with the Forum.

   

3. Unsubscribe from geoserver-users email list.

   We will continue to operate the geoserver-user list for the month of August, and then do a final synchronization of any outstanding email messages to complete the migration.

4. Navigate to the category GeoSever / User to enjoy the forum.

   

5. Use New Topic to start a new conversation.

   Only the GeoServer / user subcategory allows new topics. If the New Topic button is disabled you may be looking at the GeoServer top-level category.

6. To test please send introduce yourself we are looking forward to meeting you.

Use as a mailing list replacement

If you enjoy the out-of-band timezone friendly mailing list experience - Discourse allows you to subscribe to notifications, and use email to post and reply to topics.

1. Sign-in to Discourse as above.

2. From your profile preferences, use the email tab to adjust email settings.

   IMPORTANT: Email is only sent when you are not logged in to the discourse website!

   

3. Navigate to GeoSever User category, and use the bell to change notifications to Watching.

   

4. If you wish to update any email rules the new mailing is user.geoserver.discourse.osgeo.org

5. You can send email to geoserver-user@discourse.osgeo.org to start a new topic.

   To test please send an email to introduce yourself (rather than a test message).

Mastadon and other socials

GeoServer is occasionally active on social media:

• Mastadon: @geoserver@fosstodon.org
• LinkedIn Group
• Twitter/X: @GeoServerO - only used for emergencies.

If you enjoy social media we would love some assistance reposting and highlighting our community activity. Contact us on your preferred social media platform to help out.

This is a follow up to 2024 roadmap post outlining development opportunities.

First of all thanks to developers and organisations that have responded with offers of in-kind contributions. This blog post is assessing current progress and outlines a way forward to complete the Java 17/Jakarta EE/Spring 6 upgrades.

This post highlights development activities that are available to be worked on today, along with interested developers and commercial support providers available to work on GeoServer roadmap items.

Spring Framework 6 Tasks

The key challenge we are building towards is a spring-framework 6 update, ideally by the end of 2024 when the version we use now reaches end-of-life.

The tasks below are steps towards this goal.

Wicket 9 upgrade

Interested Parties:

• Brad has been doing amazing work with the Wicket 9 upgrade and is in need of assistance.
• GeoCat has offered to do manual A/B testing when PR is ready for testing.

Activity:

• [GEOS-11275] Wicket 9 upgrade
• geoserver#7154

Spring Security 5.8 update

Spring Security 5.8 provides a safe stepping stone ahead of the complete spring-framework 6 upgrade and is an activity that can be worked on immediately.

Interested parties:

• Andreas Watermeyer (ITS Digital Solutions) offered to work on this activity in during the initial January call out, and has indicated they are now ready to start.

Activity:

• [GEOS-11271] Upgrade spring-security to 5.8

Spring Security Core implementation of OAuth2 / OIDC

The spring-security-oauth client has reached end-of-life and a GeoServer OAuth2 support must be rewritten or migrated as a result.

There are two paths to migrate to spring-security-core implementation:

• Option: Migrate the existing community module implementations to spring-security-core in place; with as little loss of functionality as possible. This has the advantage of using existing test coverage to maintain a consistent set of functionality during migration.

• Option: Setup a community module alongside the existing implementation with the goal of making a full supported etension. This approach has the advantages of allowing organisations the ability to do A/B testing as both the old and new implementation would be available alongside each other. This has the advantage of allowing stakeholders to only fund, implement, test functionality as required without disrupting existing use.

Security integrations often require infrastructure to develop and test against, which the core GeoServer team does not have access to for automated tests. We would like to see organisations review their security integration requirements and be on hand to support this development activity.

The initial priority will support for OAuth2 and Open ID Connect (OIDC), parties interested in maintaining support for Google, GeoNode, GitHub are welcome to participate.

Interested Parties:

• Andreas Watermeyer (ITS Digital Solutions) offered to work on this activity, or test as needed.
• GeoCat is interested in this work also, with the goal of bringing the OIDC plugin up to full extension status (if financing is available).

Activity: not started

• [GEOS-11272] spring-security-oauth replacement, with spring-security 5.8

ImageN / JAI Replacement

The image processing library used by GeoServer has been donated to the open source community under the name ImageN.

The immediate goal has been to add test cases to this codebase and make an ImageN 1.0 release. Andrea has come up with the amazing idea of integrating with JAI-Ext project immediately, to benefit from the improved operators, and jumpstart test coverage.

Interested Parties:

• Jody (GeoCat) is available to support this activity, or take lead if funding is available.
• Andrea (GeoSolutions) has had a deep dive into the implications for the JAI-EXT project outlining a roadmap for project integration

We would like to see organisations that depend on GeoServer for earth observation and imagery to step forward with funding for this activity.

2024 Financial support and sponsorship

Thus far 2024 has not had a strong enough sponsorship response to support the project goals above. As a point of comparison we established a budget of $15,000 with OSGeo last year to take on an low-level API change that affected several projects.

This year GeoServer sponsorship has raised between $1,000 and $2,000 which is not enough to plan with or coordinate in-kind contributions offered thus far.

Jody has worked with the OSGeo board to make adjustments to the sponsorship:

• Guidance has been provided for appropriate sponsorship levels for individual consultants, small organisation, companies and public institutions of different sizes.
• There are clear examples of how to sponsor and donate, along with the the perks and publicity associated with financial support
• GeoServer has a new sponsorship page on our website collecting this information
• GeoServer now lists sponsors logos on our home page, alongside core contributors.

We would like to thank everyone who has responded thus far:

• Sponsors: How 2 Map, illustreets
• Individual Donations: Peter Rushforth, Marco Lucarelli, Gabriel Roldan, Jody Garnett, Manuel Timita, Andrea Aime

GeoServer 2.25.3 release is now available with downloads (bin, war, windows), along with docs and extensions.

This is a stable release of GeoServer recommended for production use. GeoServer 2.25.3 is made in conjunction with GeoTools 31.3. This release is smaller than usual due to the earlier 2.25.2 security update that was released earlier this month.

Thanks to Ian Turton for making this release.

Release notes

Improvement:

• GEOS-11336 security-keycloak: upgrade keycloak version
• GEOS-11424 Speed up web-ui WorkspaceAdminComponentAuthorizer
• GEOS-11441 DisabledServiceResourceFilter spams debugging logs with property accesses
• GEOS-11442 Cache availability of gdal_translate in gdal_translate based WCS output formats
• GEOS-11443 REST API does not take effect immediately due to 10 minute authentication cache

Bug:

• GEOS-11446 [INSPIRE] Incorrect behavior for unsupported languages
• GEOS-11462 500 error thrown when double adding a user to a group via REST with JDBC user/group services

Task:

• GEOS-11464 Update Jackson 2 libs from 2.17.1 to 2.17.2

For the complete list see 2.25.3 release notes.

Community Updates

Community module development:

• GEOS-10690 Task manager plugin is missing dependencies
• GEOS-11111 Open search for EO community module: STAC search page has wrong self link
• GEOS-11438 OpenSearch for EO/STAC lack the service configuration panel
• GEOS-11439 JDBCOpenSearch access should cache the list of type names in request scope
• GEOS-11445 OGCAPI ServiceDescriptors
• GEOS-11469 Datadir catalog loader does not decrypt HTTPStoreInfo passwords

Community modules are shared as source code to encourage collaboration. If a topic being explored is of interest to you, please contact the module developer to offer assistance.

About GeoServer 2.25 Series

Additional information on GeoServer 2.25 series:

• GeoServer 2.25 User Manual
• GeoServer 2024 Roadmap Plannings
• GeoServer 2024 Q3 Developer Update
• Raster Attribute Table extension
• Individual contributor clarification

Release notes: ( 2.25.3 | 2.25.2 | 2.25.1 | 2.25.0 | 2.25-RC )

GeoSpatial Techno is a startup focused on geospatial information that is providing e-learning courses to enhance the knowledge of geospatial information users, students, and other startups. The main approach of this startup is providing quality, valid specialized training in the field of geospatial information.

( YouTube | LinkedIn | Facebook | X )

Utilizing the Demo Section in Geoserver

In this session we aim to provide content on how to use the Demo menu and its modules in GeoServer and teach the process of making different requests and getting responses from the server. If you want to access the complete tutorial, simply click on the link.

Introduction

The Demo page provides valuable tool to help you practice with requests and understand how GeoServer works. The Demo Requests is used to create and test requests to GeoServer. The user can see the response to successful requests, or troubleshoot problems. To become familiar with the demo page, navigate to Demos to open the GeoServer Demos page. This page contains these options:

• Demo Requests
• SRS List
• Reprojection Console
• WCS Request Builder.

If you have installed the WPS extension, you will see an additional option called WPS Request Builder.

Note. These tools are for the public like Layer Preview, you do not need to be logged into GeoServer to access this page.

Note. This video was recorded on GeoServer 2.22.4, which is not the most up-to-date version. Currently, versions 2.24.x and 2.25.x are supported. To ensure you have the latest release, please visit this link. and avoid using older versions of GeoServer.

Demo Request

This page has examples of WMS, WCS, and WFS requests for GeoServer that you can use to examine and change. To learn about WMS, WFS, and WCS standards, simply click on the link.

Now let’s explore some basic operations:

• From the drop-down list, you can select a set of prepared requests. They are listed with a syntax declaring the standard as a prefix and the standard’s version as a suffix. Choose WFS_getCapabilities-1.1.xml.
• Press the Submit button. A new panel is shown, and, after a while, it lists the XML response from GeoServer.
• Another basic WFS operation is getFeature, which will retrieve a feature for you. Select WFS_getFeature-1.0.xml. If you look at the XML code, you can see a clear reference to the topp:states layer, which is included in the sample set.
• Press the Submit button. A new panel is shown, and, after a while, it lists the XML response from GeoServer. The code is a GML representation of the features with fid = 3, as requested in the filter.

The Demo requests interface lets you select sample requests and modify them to perform testing on GeoServer. When in doubt about a specific operation, this application should be the first point where you go to debug. From here, you can concentrate on the request’s syntax, avoiding network issues or other problems that you may have experienced with an external client.

New Feature: For GeoServer 2.25.2 the Demo Request page has been improved to show response Headers, and provide the option to pretty print XML output.

SRS List

GeoServer natively supports almost 4000 Spatial Referencing Systems (SRS), also known as projections, and more can be added. A spatial reference system defines an ellipsoid, a datum using that ellipsoid, and either a geocentric, geographic or projection coordinate system. This page lists all SRS info known to GeoServer.

The Code column refers to the unique integer identifier of that spatial reference system. Each code is linked to a more detailed description page, accessed by clicking on that code. Now let’s filter the projection list:

• In the Search textbox, type in the project code for the basic projection, 4326 or WGS 84; then press Enter.
• Click on the projection code to show the projection details that include:
  • A short text description of the SRS
  • An EPSG or Internal description of the SRS, provides an overview of how each projection is defined. It includes several parameters formatted in the WKT format.
  • And a map showing you the area of validity or bounding box for the SRS. For 4326, it is the planet’s surface.
• Repeat these steps to review another code 32633 which is the WGS 84, UTM zone 33N. Please consider the area of validity and the countries eligible to use this SRS.

Reprojection console

The reprojection console allows you to calculate and quickly test coordinate transformation. You can use it to convert a single coordinate or WKT geometry and transform it from one CRS to another. In this recipe, you’ll discover a simple, yet very useful tool that ships with GeoServer. It lets you have a look at how coordinates change when you move data from one CRS to another.

• From the list, select the Reprojection console.
• Insert EPSG:4326 in the Source CRS field and EPSG:32632 in the Target CRS field. Then, enter the coordinates of the POINT in the Geometry of Source CRS field, similar to what you see on the video. In this example, we used the coordinates of the San Siro stadium in Milan.
• Click on the Forward Transformation link; GeoServer calculates the new coordinates for you and fills the Geometry of Target CRS textbox. Use Forward transformation to convert from source CRS to target CRS, and Backward transformation to convert from target CRS to source CRS. You can also view the underlying calculation GeoServer is using to perform the transformation.

WCS Request Builder

The WCS Request Builder is a tool for generating and executing WCS requests. Since WCS requests can be cumbersome to the author, this tool can make working with WCS much easier. To access the WCS Request Builder, Select WCS Request Builder from the list of demos. The WCS Request Builder consists of a form that can be used to generate several different types of requests. When first opened, the form is short, only including these options:

• WCS Version—Version of WCS to use when crafting the request.
• Coverage name—Coverage to use in the request.

Note. All other options displayed will be non-functional until Coverage name is selected. Once selected, the remainder of the form will be displayed. Watch the video for a full explanation of these options:

• Spatial subset
• Coordinate reference system
• Specify source grid manually (1.0.0 only)
• Target coverage layout (1.1.1 only)
• Target CRS
• Output format

There is also a link for Describe coverage next to the Coverage name which will execute a WCS DescribeCoverage request for the particular layer. At the bottom of the form are two buttons for form submission:

• Get Coverage: It executes a GetCoverage request using the parameters in the form.
• Generate GetCoverage XML: Clicking this button generates the GetCoverage request based on the form parameters.

By using this generated XML code, you can easily construct and customize your GetCoverage requests with various parameters, making it easier to retrieve the desired coverage data from GeoServer.

New Feature: For GeoServer 2.25.2 the WCS Request Builder has new option to open the generated request in the Demo Request Builder. This is very helpful allowing the response to be shown on the page, rather than downloaded in the browser.

WPS Request Builder

GeoServer with the WPS extension installed includes a request builder for generating and executing WPS processes. Using this tool can greatly simplify the process of authoring WPS requests and making your work with WPS much more convenient and efficient. It’s always nice to have assistance in tasks that can be complex or time-consuming. This tool can be a valuable asset in your WPS workflow.

In future sessions, we’ll dive deep into the Web Processing Service or WPS and explore its functionalities and how to use different functions in detail. So get ready to expand your knowledge and learn how to leverage the power of WPS for your geospatial analysis needs!

New Feature: For GeoServer 2.25.2 the WPS Request Builder has the new option to open the generated request in the Demo Request Builder.

In this session, we took a brief journey through GeoServer Demo section. we have explored the Demo menu and its modules in GeoServer. If you want to access the complete tutorial, simply click on the link.