Rename master branch to main (#3539)

Author: artembilan

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,5 +2,5 @@
 Thanks for contributing to Spring Integration. 
 Please provide a brief description of your pull-request and reference any related issue numbers (prefix references with #) or StackOverflow questions.
 
-See the [Contributor Guidelines for more information](https://github.com/spring-projects/spring-integration/blob/master/CONTRIBUTING.adoc).
+See the [Contributor Guidelines for more information](https://github.com/spring-projects/spring-integration/blob/main/CONTRIBUTING.adoc).
 -->

.github/workflows/pr-build-workflow.yml

@@ -2,7 +2,7 @@ name: Pull Request build
 
 on:
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   build:

CONTRIBUTING.adoc

@@ -8,7 +8,7 @@ Please refer back to this document as a checklist before issuing any pull reques
 
 == Code of Conduct
 
-Please see our https://github.com/spring-projects/.github/blob/master/CODE_OF_CONDUCT.md[code of conduct]
+Please see our https://github.com/spring-projects/.github/blob/main/CODE_OF_CONDUCT.md[code of conduct]
 
 == Reporting Security Vulnerabilities
 
@@ -49,7 +49,7 @@ _you should see only 'origin' - which is the fork you created for your own githu
 _you should now see 'upstream' in addition to 'origin' where 'upstream' is the Spring repository from which releases are built_
 6. `git fetch --all`
 7. `git branch -a`
-_you should see branches on origin as well as upstream, including 'master'_
+_you should see branches on origin as well as upstream, including 'main'_
 
 == Build from Source
 
@@ -126,36 +126,37 @@ You can build and test only a specific module if your contribution is only over
 * If you want to collaborate with another contributor, have them fork your repository (add it as a remote) and `git fetch <your-username>` to grab your branch.
 Alternatively, they can use `git fetch --all` to sync their local state with all of their remotes.
 * If you grant that collaborator push access to your repository, they can even apply their changes to your branch.
-* When ready for your contribution to be reviewed for potential inclusion in the master branch of the canonical `spring-integration` repository (what you know as 'upstream'), issue a pull request to the SpringSource repository (for more detail, see https://help.github.com/articles/using-pull-requests/[Using pull requests]).
-* The project lead may merge your changes into the upstream master branch as-is, he may keep the pull request open yet add a comment about something that should be modified, or he might reject the pull request by closing it.
-* A prerequisite for any pull request is that it will be cleanly merge-able with the upstream master's current state.
+* When ready for your contribution to be reviewed for potential inclusion in the main branch of the canonical `spring-integration` repository (what you know as 'upstream'), issue a pull request to the SpringSource repository (for more detail, see https://help.github.com/articles/using-pull-requests/[Using pull requests]).
+* The project lead may merge your changes into the upstream main branch as-is, he may keep the pull request open yet add a comment about something that should be modified, or he might reject the pull request by closing it.
+* A prerequisite for any pull request is that it will be cleanly merge-able with the upstream main's current state.
 **This is the responsibility of any contributor.**
 If your pull request cannot be applied cleanly, the project lead will most likely add a comment requesting that you make it merge-able.
 For a full explanation, see https://git-scm.com/book/en/Git-Branching-Rebasing[the Pro Git section on rebasing].
 As stated there: _"> Often, you’ll do this to make sure your commits apply cleanly on a remote branch — perhaps in a project to which you’re trying to contribute but that you don’t maintain."_
 
 == Keeping your Local Code in Sync
 
-* As mentioned above, you should always work on topic branches (since 'master' is a moving target). However, you do want to always keep your own 'origin' master branch in synch with the 'upstream' master.
+* As mentioned above, you should always work on topic branches (since 'main' is a moving target). 
+However, you do want to always keep your own 'origin' main branch in synch with the 'upstream' main.
 * Within your local working directory, you can sync up all remotes' branches with: `git fetch --all`
-* While on your own local master branch: `git pull upstream master` (which is the equivalent of fetching upstream/master and merging that into the branch you are in currently)
+* While on your own local main branch: `git pull upstream main` (which is the equivalent of fetching upstream/main and merging that into the branch you are in currently)
 * Now that you're in synch, switch to the topic branch where you plan to work, e.g.: `git checkout -b GH-123`
 * When you get to a stopping point: `git commit`
-* If changes have occurred on the upstream/master while you were working you can sync again:
-    - Switch back to master: `git checkout master`
-    - Then: `git pull upstream master`
+* If changes have occurred on the upstream/main while you were working you can sync again:
+    - Switch back to main: `git checkout main`
+    - Then: `git pull upstream main`
     - Switch back to the topic branch: `git checkout GH-123` (no -b needed since the branch already exists)
-    - Rebase the topic branch to minimize the distance between it and your recently synced master branch: `git rebase master`
+    - Rebase the topic branch to minimize the distance between it and your recently synced main branch: `git rebase main`
 (Again, for more detail see https://git-scm.com/book/en/Git-Branching-Rebasing[the Pro Git section on rebasing]).
-* **Note** While it is generally recommended to __not__ re-write history by using `push --force`, and we do not do this on `master` (and release) branches in the main repo, we require topic branches for pull requests to be rebased before merging, in order to maintain a clean timeline and avoid "merge" commits.
+* **Note** While it is generally recommended to __not__ re-write history by using `push --force`, and we do not do this on `main` (and release) branches in the main repo, we require topic branches for pull requests to be rebased before merging, in order to maintain a clean timeline and avoid "merge" commits.
 * If, while rebasing for the merge, we find significant conflicts, we may ask you to rebase and `push --force` to your topic branch after resolving the conflicts.
-* Assuming your pull request is merged into the 'upstream' master, you will end up pulling that change into your own master eventually and, at that time, you may decide to delete the topic branch from your local repository and your fork (origin) if you pushed it there.
+* Assuming your pull request is merged into the 'upstream' main, you will end up pulling that change into your own main eventually and, at that time, you may decide to delete the topic branch from your local repository and your fork (origin) if you pushed it there.
     - to delete the local branch: `git branch -d GH-123`
     - to delete the branch from your origin: `git push origin :GH-123`
 
 == Maintain a linear commit history
 
-When merging to master, the project __always__ uses fast-forward merges.
+When merging to main, the project __always__ uses fast-forward merges.
 As discussed above, when issuing pull requests, please ensure that your commit history is linear.
 From the command line you can check this using:
 
@@ -181,7 +182,7 @@ This command, will provide the following output, which in this case shows a nice
 ----
 
 If you see intersecting lines, that usually means that you forgot to rebase you branch.
-As mentioned earlier, **please rebase against master** before issuing a pull request.
+As mentioned earlier, **please rebase against main** before issuing a pull request.
 
 == Follow the Code Style
 

README.md

@@ -1,9 +1,9 @@
-Spring Integration [<img src="https://build.spring.io/plugins/servlet/wittified/build-status/INT-MASTER">](https://build.spring.io/browse/INT-MASTER) [![Join the chat at https://gitter.im/spring-projects/spring-integration](https://badges.gitter.im/spring-projects/spring-integration.svg)](https://gitter.im/spring-projects/spring-integration?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+Spring Integration [<img src="https://build.spring.io/plugins/servlet/wittified/build-status/INT-MAIN">](https://build.spring.io/browse/INT-MAIN) [![Join the chat at https://gitter.im/spring-projects/spring-integration](https://badges.gitter.im/spring-projects/spring-integration.svg)](https://gitter.im/spring-projects/spring-integration?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 ==================
 
 # Code of Conduct
 
-Please see our [Code of conduct](https://github.com/spring-projects/.github/blob/master/CODE_OF_CONDUCT.md).
+Please see our [Code of conduct](https://github.com/spring-projects/.github/blob/main/CODE_OF_CONDUCT.md).
 
 # Reporting Security Vulnerabilities
 
@@ -73,7 +73,7 @@ File -> Open... -> and select build.gradle from spring-integration project root
 
 # Guidelines
 
-See also [Contributor Guidelines](https://github.com/spring-projects/spring-integration/blob/master/CONTRIBUTING.adoc).
+See also [Contributor Guidelines](https://github.com/spring-projects/spring-integration/blob/main/CONTRIBUTING.adoc).
 
 # Resources
 

src/reference/asciidoc/barrier.adoc

@@ -83,4 +83,4 @@ public class Config {
 }
 ----
 
-For an example of this component, see the https://github.com/spring-projects/spring-integration-samples/tree/master/basic/barrier[barrier sample application].
+For an example of this component, see the https://github.com/spring-projects/spring-integration-samples/tree/main/basic/barrier[barrier sample application].

src/reference/asciidoc/changes-1.0-2.0.adoc

@@ -90,7 +90,7 @@ See also the following blog: https://spring.io/blog/2010/03/29/using-udp-and-tcp
 
 Twitter adapters provides support for sending and receiving Twitter status updates as well as direct messages.
 You can also perform Twitter Searches with an inbound channel adapter.
-See https://github.com/spring-projects/spring-integration-extensions/tree/master/spring-integration-social-twitter[Spring Integration Social Twitter] for more details.
+See https://github.com/spring-projects/spring-integration-extensions/tree/main/spring-integration-social-twitter[Spring Integration Social Twitter] for more details.
 
 [[new-xmpp]]
 ===== XMPP Adapters

src/reference/asciidoc/changes-2.0-2.1.adoc

@@ -209,13 +209,13 @@ The Spring Integration Git repository is located at: https://github.com/spring-p
 For the project, we also improved the process of providing code contributions.
 Further, we ensure that every commit is peer-reviewed.
 In fact, core committers now follow the same process as contributors.
-For more details, see https://github.com/spring-projects/spring-integration/blob/master/CONTRIBUTING.adoc[Contributing].
+For more details, see https://github.com/spring-projects/spring-integration/blob/main/CONTRIBUTING.adoc[Contributing].
 
 [[x2.1-sonar]]
 ===== Improved Source Code Visibility with Sonar
 
 In an effort to provide better source code visibility and consequently to monitor the quality of Spring Integration's source code, we set up an instance of https://www.sonarqube.org/[Sonar].
-We gather metrics nightly and make them available at https://sonar.spring.io/dashboard?id=org.springframework.integration%3Aspring-integration%3Amaster[sonar.spring.io].
+We gather metrics nightly and make them available at https://sonar.spring.io/dashboard?id=org.springframework.integration%3Aspring-integration%3Amain[sonar.spring.io].
 
 [[x2.1-new-samples]]
 ==== New Samples

src/reference/asciidoc/changes-3.0-4.0.adoc

@@ -128,7 +128,7 @@ For more information, see <<./configuration.adoc#annotations,Annotation Support>
 
 We added a new twitter endpoint: `<int-twitter-search-outbound-gateway/>`.
 Unlike the search inbound adapter, which polls by using the same search query each time, the outbound gateway allows on-demand customized queries.
-For more information, see https://github.com/spring-projects/spring-integration-extensions/tree/master/spring-integration-social-twitter[Spring Integration Social Twitter].
+For more information, see https://github.com/spring-projects/spring-integration-extensions/tree/main/spring-integration-social-twitter[Spring Integration Social Twitter].
 
 [[x4.0-gemfire-metadata]]
 ===== Gemfire Metadata Store
@@ -248,7 +248,7 @@ See <<./ftp.adoc#ftp-session-factory,FTP Session Factory>> for more information.
 
 The `StatusUpdatingMessageHandler` (`<int-twitter:outbound-channel-adapter>`) now supports the `tweet-data-expression` attribute to build a `org.springframework.social.twitter.api.TweetData` object for updating the timeline status.
 This feature allows, for example, attaching an image.
-See https://github.com/spring-projects/spring-integration-extensions/tree/master/spring-integration-social-twitter[Spring Integration Social Twitter] for more information.
+See https://github.com/spring-projects/spring-integration-extensions/tree/main/spring-integration-social-twitter[Spring Integration Social Twitter] for more information.
 
 [[x4.0-jpa-id-expression]]
 ===== JPA Retrieving Gateway: `id-expression`

src/reference/asciidoc/changes-5.0-5.1.adoc

@@ -188,7 +188,7 @@ In addition the key and trust store types can now be configured on the `DefaultT
 ==== Twitter Support
 
 Since the Spring Social project has moved to https://spring.io/blog/2018/07/03/spring-social-end-of-life-announcement[end of life status], Twitter support in Spring Integration has been moved to the Extensions project.
-See https://github.com/spring-projects/spring-integration-extensions/tree/master/spring-integration-social-twitter[Spring Integration Social Twitter] for more information.
+See https://github.com/spring-projects/spring-integration-extensions/tree/main/spring-integration-social-twitter[Spring Integration Social Twitter] for more information.
 
 [[x51.-jms]]
 ==== JMS Support

src/reference/asciidoc/codec.adoc

@@ -91,7 +91,7 @@ You can override these framework defaults by configuring the registrars mentione
 ====== Using a Custom Kryo Serializer
 
 If you need custom serialization, see the https://github.com/EsotericSoftware/kryo[Kryo] documentation, because you need to use the native API to do the customization.
-For an example, see the https://github.com/spring-projects/spring-integration/blob/master/spring-integration-core/src/main/java/org/springframework/integration/codec/kryo/MessageCodec.java[`MessageCodec`] implementation.
+For an example, see the https://github.com/spring-projects/spring-integration/blob/main/spring-integration-core/src/main/java/org/springframework/integration/codec/kryo/MessageCodec.java[`MessageCodec`] implementation.
 
 ====== Implementing KryoSerializable