Spring Boot is released under the Apache 2.0 license. If you would like to contribute something, or simply want to hack on the code this document should help you get started.
This project adheres to the Contributor Covenant code of conduct. By participating, you are expected to uphold this code. Please report unacceptable behavior to spring-code-of-conduct@pivotal.io.
We use GitHub issues to track bugs and enhancements. If you have a general usage question
please ask on Stack Overflow. The Spring Boot team and the
broader community monitor the spring-boot
tag.
If you are reporting a bug, please help to speed up problem diagnosis by providing as much information as possible. Ideally, that would include a small sample project that reproduces the problem.
Before we accept a non-trivial patch or pull request we will need you to sign the Contributor License Agreement. Signing the contributor’s agreement does not grant anyone commit rights to the main repository, but it does mean that we can accept your contributions, and you will get an author credit if we do. Active contributors might be asked to join the core team, and given the ability to merge pull requests.
None of these is essential for a pull request, but they will all help. They can also be added after the original pull request but before a merge.
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Use the Spring Framework code format conventions. If you use Eclipse and you follow the ‘Importing into eclipse’ instructions below you should get project specific formatting automatically. You can also import formatter settings using the
eclipse-code-formatter.xmlfile from theeclipsefolder. If using IntelliJ IDEA, you can use the Eclipse Code Formatter Plugin to import the same file. -
Make sure all new
.javafiles to have a simple Javadoc class comment with at least an@authortag identifying you, and preferably at least a paragraph on what the class is for. -
Add the ASF license header comment to all new
.javafiles (copy from existing files in the project) -
Add yourself as an
@authorto the.javafiles that you modify substantially (more than cosmetic changes). -
Add some Javadocs.
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A few unit tests would help a lot as well — someone has to do it.
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If no-one else is using your branch, please rebase it against the current master (or other target branch in the main project).
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When writing a commit message please follow these conventions, if you are fixing an existing issue please add
Fixes gh-XXXXat the end of the commit message (whereXXXXis the issue number).
If you don’t have an IDE preference we would recommend that you use Spring Tools Suite or Eclipse when working with the code. We use the M2Eclipse eclipse plugin for maven support. Other IDEs and tools should also work without issue.
To build the source you will need to install Apache Maven v3.2.3 or above and JDK 1.8.
The project can be built from the root directory using the standard maven command:
$ ./mvnw clean install
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Note
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You may need to increase the amount of memory available to Maven by setting
a MAVEN_OPTS environment variable with the value -Xmx512m
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If you are rebuilding often, you might also want to skip the tests and the execution of checkstyle until you are ready to submit a pull request:
$ ./mvnw clean install -DskipTests -Pfast
Multi-module Maven builds cannot directly include maven plugins that are part of the
reactor unless they have previously been built. Unfortunately this restriction causes
some compilations for Spring Boot as we include a maven plugin and use it within the
samples. The standard build works around this restriction by launching the samples via
the maven-invoker-plugin so that they are not part of the reactor. This works fine
most of the time, however, sometimes it’s useful to run a build that includes all modules
(for example when using maven-versions-plugin. We use the full build on our CI servers
and during the release process.
Running a full build is a two phase process.
1) Prepare the build
Preparing the build will compile and install the spring-boot-maven-plugin so that it
can be referenced during the full build. It also generates a settings.xml file that
enables a snapshot, milestone or release profiles based on the version being
build. To prepare the build, from the root directory use:
$ ./mvnw -P snapshot,prepare install -DskipTests
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Note
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You may notice that preparing the build also changes the
spring-boot-starter-parent POM. This is required for our release process to work
correctly.
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2) Run the full build
Once the build has been prepared, you can run a full build using the following commands:
$ ./mvnw -s ./settings.xml -f spring-boot-full-build -P full clean install
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Note
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As for the standard build, you may need to increase the amount of memory available
to Maven by setting a MAVEN_OPTS environment variable with the value
-Xmx512m. We generate more artifacts when running the full build
(such as Javadoc jars), so you may find the process a little slower than the standard build.
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You can import the Spring Boot code into any Eclipse Mars based distribution. The easiest
way to setup a new environment is to use the Eclipse Installer with the provided
.setup file.
Spring Boot includes a .setup files which can be used with the Eclipse Installer to
provision a new environment. To use the installer:
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Download and run the latest Eclipse Installer from eclipse.org/downloads/.
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Switch to "Advanced Mode" using the drop down menu on the right.
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Select “Eclipse IDE for Java Developers” under “Eclipse.org” as the product to install and click “next”.
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For the “Project” click on “+” to add a new setup file. Select “Github Projects” and browser for
<checkout>/eclipse/spring-boot-project.setupfrom your locally cloned copy of the source code. Click “OK” to add the setup file to the list. -
Double-click on “Spring Boot” from the project list to add it to the list that will be provisioned then click “Next”.
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Click show all variables and make sure that “Checkout Location” points to the locally cloned source code that you selected earlier. You might also want to pick a different install location here.
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Click “Finish” to install the software.
Once complete you should find that a local workspace has been provisioned complete with all required Eclipse plugins. Projects will be grouped into working-sets to make the code easier to navigate.
If you prefer to install Eclipse yourself we recommend that you use the M2Eclipse eclipse plugin. If you don’t already have m2eclipse installed it is available from the "Eclipse marketplace".
Spring Boot includes project specific source formatting settings, in order to have these work with m2eclipse, we provide additional Eclipse plugins that you can install:
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Select “Help” → “Install New Software”.
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Add
https://dl.bintray.com/philwebb/m2eclipse-maveneclipseas a site. -
Install "Maven Integration for the maven-eclipse-plugin"
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Select “Help” → “Install New Software”.
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Add
https://dl.bintray.com/philwebb/spring-eclipse-code-formatter/as a site. -
Install "Spring Code Formatter"
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Note
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These plugins are optional. Projects can be imported without the plugins, your code changes just won’t be automatically formatted. |
With the requisite eclipse plugins installed you can select
import existing maven projects from the file menu to import the code. You will
need to import the root spring-boot pom and the spring-boot-samples pom separately.
The sample applications are used as integration tests during the build (when you
mvn install). Due to the fact that they make use of the spring-boot-maven-plugin
they cannot be called directly, and so instead are launched via the
maven-invoker-plugin. If you encounter build failures running the integration tests,
check the build.log file in the appropriate sample directory.