Eclipse Guide

A reference for developing GeoServer with Eclipse.

Setting up Eclipse

Use of Maven M2 Plugin

The Eclipse built-in support for maven can be used to build and run GeoServer, see Eclipse M2 Quickstart for details.

Use of maven eclipse plugin

The maven eclipse plugin is used to generate eclipse projects for a set of modules:

mvn eclipse:eclipse

After which the modules can be imported into an eclipse workspace, see Maven Eclipse Plugin Quickstart for details.

A useful feature of the plugin is the ability to download associated source code for third party dependencies. This is done with the downloadSources flag:

mvn -DdownloadSources eclipse:eclipse


The first time you enable the downloadSources flag the build will take a long time as it will attempt to download the sources for every single library GeoServer depends on.

Running and debugging

Run or debug the class org.geoserver.web.Start in the web-app module. The steps to do so are detailed in the Maven Eclipse Plugin Quickstart or Eclipse M2 Quickstart.

Running GeoServer with Extensions

By default, GeoServer will run without any extensions enabled. In order to run GeoServer with extensions, the web-app module declares a number of profiles used to enable specific extensions when running Start. To enable an extension, re-generate the root eclipse profile with the appropriate maven profile(s) enabled:

% mvn eclipse:eclipse -P wps

The full list of supported profiles can be found in src/web/app/pom.xml.

Setting the data directory

If unset, GeoServer will default to the minimal directory inside of the web-app module for its data directory. To change this:

  1. Open Debug Configurations... from the Eclipse menu

  2. Select the Start configuration, select the Arguments panel and specify the -DGEOSERVER_DATA_DIR parameter, setting it to the absolute path of the data directory


Changing the default port for Jetty

If unset, Jetty will default to port 8080. To change this:

  1. Open the Arguments panel of the Start configuration as described in the above section

  2. Specify the -Djetty.port parameter, setting it to the desired port


Configuring JNDI resources in Jetty

JNDI resources such as data sources can be configured by supplying a Jetty server configuration file named in the system property jetty.config.file, specified as a line in VM arguments in the Arguments panel of the launch configuration for Start (separate lines are joined when the JVM is launched). The path to the configuration file is relative to the root of the web-app module, in which the launch configuration runs. Naming factory system properties must also be configured for Jetty. For example, VM arguments could include:


The following Jetty server configuration file configures a JNDI data source java:comp/env/jdbc/demo that is a connection pool for an Oracle database:

<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Mort Bay Consulting//DTD Configure//EN" "">
<Configure class="org.eclipse.jetty.server.Server">
    <New class="">
            <New class="org.apache.commons.dbcp.BasicDataSource">
                <Set name="driverClassName">oracle.jdbc.OracleDriver</Set>
                <Set name="url"></Set>
                <Set name="username">claudius</Set>
                <Set name="password">s3cr3t</Set>
                <Set name="maxActive">20</Set>
                <Set name="maxIdle">10</Set>
                <Set name="minIdle">0</Set>
                <Set name="maxWait">10000</Set>
                <Set name="minEvictableIdleTimeMillis">300000</Set>
                <Set name="timeBetweenEvictionRunsMillis">300000</Set>
                <Set name="numTestsPerEvictionRun">20</Set>
                <Set name="poolPreparedStatements">true</Set>
                <Set name="maxOpenPreparedStatements">100</Set>
                <Set name="testOnBorrow">true</Set>
                <Set name="validationQuery">SELECT SYSDATE FROM DUAL</Set>
                <Set name="accessToUnderlyingConnectionAllowed">true</Set>

Jetty does not mandate a reference-ref in GeoServer WEB-INF/web.xml, so there is no need to modify that file. No Jetty-specific information is required inside the GeoServer web-app module or data directory, so JNDI resources can be tested under Jetty for later deployment under Tomcat. See also the tutorial Setting up a JNDI connection pool with Tomcat in the GeoServer User Manual.

Starting Jetty with an open SSL port

The SSL port used 8443.

  1. Open the Arguments panel of the Start configuration.

  2. Specify the -Dssl.hostname parameter, setting it to the full qualified host name of the box running Jetty.


On first time startup, a key store is created in <home directory>/.geoserver/keystore.jks. The password is changeit and the key store contains a self-signed certificate for the host name passed in the ssl.hostname parameter.

Test the SSL connection by opening a browser and entering The browser should complain about the self-signed certificate which does not hurt for test and development setups.

Eclipse preferences

Code formatting

The Google formatter plugin is embedded in the build and will reformat the code at each build, matching the coding conventions. Please always build before committing!

The google-java-format project offers a plugin for Eclipse, but we are waiting an support for ASOP variant. While we wait for this fix build once on the command line, to format the any code changes before committing.

As workaround you could use a modified version with 4 spaces indent by default, putting the jar file on Eclipse dropins folder.

You may also:

  1. Download

  2. Navigate to Java, Code Style, Formatter and click Import...

  3. Select the eclipse-java-google-style.xml file downloaded in step 1

  4. Click Apply

  5. We follow Google Code Formatting with the AOSP variant (4 spaces indent instead of 2).

    For more information see GeoTools Coding Style page.

Code templates

  1. Download codetemplates.xml.

  2. Navigate to Java, Code Style, Code Templates and click Import...

  3. Select the codetemplates.xml file downloaded in step 1

  4. Click Apply


Text editors

  1. Navigate to General, Editors, Text Editors

  2. Check Insert spaces for tabs

  3. Check Show print margin and set Print margin column to “100”

  4. Check Show line numbers

  5. Check Show whitespace characters (optional)


    Showing whitespace characters can help ensure that unnecessary whitespace is not unintentionally committed.

  6. Click Apply