= Contributing to Spring Boot 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. == Code of Conduct This project adheres to the Contributor Covenant link:CODE_OF_CONDUCT.adoc[code of conduct]. By participating, you are expected to uphold this code. Please report unacceptable behavior to spring-code-of-conduct@pivotal.io. == Using GitHub Issues We use GitHub issues to track bugs and enhancements. If you have a general usage question please ask on https://stackoverflow.com[Stack Overflow]. The Spring Boot team and the broader community monitor the https://stackoverflow.com/tags/spring-boot[`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 https://github.com/spring-projects/spring-boot-issues[sample project] that reproduces the problem. == Reporting Security Vulnerabilities If you think you have found a security vulnerability in Spring Boot please *DO NOT* disclose it publicly until we've had a chance to fix it. Please don't report security vulnerabilities using GitHub issues, instead head over to https://pivotal.io/security and learn how to disclose them responsibly. == Sign the Contributor License Agreement Before we accept a non-trivial patch or pull request we will need you to https://cla.pivotal.io/sign/spring[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. == Code Conventions and Housekeeping 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. * We use the https://github.com/spring-io/spring-javaformat/[Spring JavaFormat] project to apply code formatting conventions. If you use Eclipse and you follow the '`Importing into eclipse`' instructions below you should get project specific formatting automatically. You can also install the https://github.com/spring-io/spring-javaformat/#intellij-idea[Spring JavaFormat IntelliJ Plugin] or format the code from the Maven build by running `./mvnw io.spring.javaformat:spring-javaformat-maven-plugin:apply`. * The build includes checkstyle rules for many of our code conventions. Run `./mvnw validate` if you want to check you changes are compliant. * Make sure all new `.java` files to have a simple Javadoc class comment with at least an `@author` tag identifying you, and preferably at least a paragraph on what the class is for. * Add the ASF license header comment to all new `.java` files (copy from existing files in the project) * Add yourself as an `@author` to the `.java` files that you modify substantially (more than cosmetic changes). * Add some Javadocs. * A few unit tests would help a lot as well -- someone has to do it. * If no-one else is using your branch, please rebase it against the current master (or other target branch in the main project). * When writing a commit message please follow https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html[these conventions], if you are fixing an existing issue please add `Fixes gh-XXXX` at the end of the commit message (where `XXXX` is the issue number). == Working with the Code If you don't have an IDE preference we would recommend that you use https://spring.io/tools/sts[Spring Tools Suite] or https://eclipse.org[Eclipse] when working with the code. We use the https://eclipse.org/m2e/[M2Eclipse] eclipse plugin for maven support. Other IDEs and tools should also work without issue. === Building from Source Spring Boot source can be built from the command line using https://maven.apache.org/run-maven/index.html[Apache Maven] on JDK 1.8 or above. We include '`Maven Wrapper`' scripts (`./mvnw` or `mvnw.bat`) that you can run rather than needing to install Maven locally. ==== Default Build The project can be built from the root directory using the standard Maven command: [indent=0] ---- $ ./mvnw clean install ---- NOTE: You may need to increase the amount of memory available to Maven by setting a `MAVEN_OPTS` environment variable with the value `-Xmx512m` 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: [indent=0] ---- $ ./mvnw clean install -DskipTests -Pfast ---- ==== Full Build You can run a full build using the following command: [indent=0] ---- $ ./mvnw -Pfull clean install ---- NOTE: 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. [TIP] ==== If you want to run a build without the samples and integration tests, building the `spring-boot-project` module is enough. You can cd there and run the same command, or you can run this from the top-level directory: [indent=0] ---- $ ./mvnw -f spring-boot-project -Pfull clean install ---- ==== === Importing into Eclipse You can import the Spring Boot code into any Eclipse Oxygen based distribution. The easiest way to setup a new environment is to use the Eclipse Installer with the provided `.setup` file (in the `/eclipse` folder). ==== Using the Eclipse Installer Spring Boot includes a `.setup` files which can be used with the Eclipse Installer to provision a new environment. To use the installer: * Download and run the latest Eclipse Installer from https://www.eclipse.org/downloads/[eclipse.org/downloads/] (under "Get Eclipse"). * Switch to "Advanced Mode" using the drop down menu on the right. * Select "`Eclipse IDE for Java Developers`" under "`Eclipse.org`" as the product to install and click "`next`". * For the "`Project`" click on "`+`" to add a new setup file. Select "`Github Projects`" and browser for `/eclipse/spring-boot-project.setup` from 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`". * 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. * 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. ==== Manual Installation with M2Eclipse If you prefer to install Eclipse yourself you should use the https://eclipse.org/m2e/[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 an additional Eclipse plugin that you can install: ===== Install the Spring Formatter plugin * Select "`Help`" -> "`Install New Software`". * Add `https://dl.bintray.com/spring/javaformat-eclipse/` as a site. * Install "Spring Java Format". NOTE: The plugin is 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. === Importing into IntelliJ IDEA To open the project in IntelliJ IDEA, select "`File`" -> "`Open`" and then click on the root `pom.xml`. ==== Install the Spring Formatter plugin If you haven't done so, install the formatter plugin so that proper formatting rules are applied automatically when you reformat code in the IDE. * Download the latest https://search.maven.org/search?q=g:io.spring.javaformat%20AND%20a:spring-javaformat-intellij-plugin[IntelliJ IDEA plugin]. * Select "`IntelliJ IDEA`" -> "`Preferences`". * Select "`Plugins`". * Select the wheel and "`Install Plugin from Disk...`". * Select the jar file you've downloaded. ==== Import additional code style The formatter does not cover all rules (such as order of imports) and an additional file needs to be added. * Select "`IntelliJ IDEA`" -> "`Preferences`". * Select "`Editor`" -> "`Code Style`". * Select the wheel and "`Import Scheme`" -> "`IntelliJ IDEA code style XML`". * Select `idea/codeStyleConfig.xml` from this repository. === Importing into Other IDEs Maven is well supported by most Java IDEs. Refer to your vendor documentation. == Integration Tests The sample applications are used as integration tests during the build (when you `./mvnw 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. == Cloning the git repository on Windows Some files in the git repository may exceed the Windows maximum file path (260 characters), depending on where you clone the repository. If you get `Filename too long` errors, set the `core.longPaths=true` git option: ``` git clone -c core.longPaths=true https://github.com/spring-projects/spring-boot ```