![]() JGit's Nullable type was added[1] in the hope of being able to add nullness annotations that (a) do not preclude building and running with Java 7 and (b) could be shared by Gerrit, which uses a custom Nullable type for other reasons[2]. Sharing a type is useful because Eclipse's null analysis is only able to use one Nullable type at a time in a given workspace (so for this analysis to function in a workspace used to develop Gerrit, JGit and Gerrit would need to use the same Nullable type). The new Nullable type has CLASS instead of RUNTIME retention because there wasn't any obvious use for the annotation at run time. Gerrit uses the Nullable annotation to communicate with Guice. Guice injection happens at runtime, so it needs to be able to read the @Nullable annotations at run time[3]. Otherwise Guice produces provisioning errors, such as 3) null returned by binding at com.google.gerrit.lucene.LuceneChangeIndex$Factory.create() but parameter 7 of com.google.gerrit.lucene.LuceneChangeIndex.<init>() is not @Nullable Switch to RUNTIME retention to avoid this. While at it, update the javadoc to explain more clearly how this annotation relates to other Nullable types[4]. This should make it clearer why JGit needed another Nullable type: A. Avoiding dependency on Java 8 B. RUNTIME retention to allow Guice to read the annotation at run time C. Named Nullable so Guice can recognize the annotation D. Not an addition to Java EE's javax.annotation package, to avoid the split-package problem[2] that prevents the annotation from being readable at run time when loaded from an OSGi container E. Avoiding heavyweight dependencies, deprecated dependencies, and dependencies on package internals org.checkerframework.checker.nullness.qual.Nullable: A com.sun.istack.internal.Nullable: B, E *.CheckForNull, *.NullAllowed, etc: C edu.umd.cs.findbugs.annotations.Nullable: B, E javax.annotation.Nullable: D org.eclipse.jdt.annotation.Nullable: B org.jetbrains.annotations.Nullable: B org.jmlspecs.annotation.Nullable: E android.annotation.Nullable, android.support.annotation.Nullable: E [1] https://git.eclipse.org/r/59993 [2] https://gerrit-review.googlesource.com/50112 [3] https://github.com/google/guice/blob/master/core/src/com/google/inject/internal/Nullability.java [4] https://github.com/typetools/checker-framework/blob/5832a01f1/checker/src/org/checkerframework/checker/nullness/NullnessAnnotatedTypeFactory.java#L118 http://types.cs.washington.edu/checker-framework/current/checker-framework-manual.html#nullness-related-work Change-Id: I6c482653d2b53e3509abb11211b67fc29cf2949c Signed-off-by: Jonathan Nieder <jrn@google.com> |
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org.eclipse.jgit | ||
org.eclipse.jgit.ant | ||
org.eclipse.jgit.ant.test | ||
org.eclipse.jgit.archive | ||
org.eclipse.jgit.http.apache | ||
org.eclipse.jgit.http.server | ||
org.eclipse.jgit.http.test | ||
org.eclipse.jgit.junit | ||
org.eclipse.jgit.junit.http | ||
org.eclipse.jgit.packaging | ||
org.eclipse.jgit.pgm | ||
org.eclipse.jgit.pgm.test | ||
org.eclipse.jgit.test | ||
org.eclipse.jgit.ui | ||
tools | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
CONTRIBUTING.md | ||
LICENSE | ||
README.md | ||
pom.xml |
README.md
Java Git
An implementation of the Git version control system in pure Java.
This package is licensed under the EDL (Eclipse Distribution License).
JGit can be imported straight into Eclipse, built and tested from there, but the automated builds use Maven.
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org.eclipse.jgit
A pure Java library capable of being run standalone, with no additional support libraries. It provides classes to read and write a Git repository and operate on a working directory.
All portions of JGit are covered by the EDL. Absolutely no GPL, LGPL or EPL contributions are accepted within this package.
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org.eclipse.jgit.java7
Extensions for users of Java 7.
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org.eclipse.jgit.ant
Ant tasks based on JGit.
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org.eclipse.jgit.archive
Support for exporting to various archive formats (zip etc).
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org.eclipse.jgit.http.apache
Apache httpclient support
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org.eclipse.jgit.http.server
Server for the smart and dumb Git HTTP protocol.
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org.eclipse.jgit.pgm
Command-line interface Git commands implemented using JGit ("pgm" stands for program).
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org.eclipse.jgit.packaging
Production of Eclipse features and p2 repository for JGit. See the JGit Wiki on why and how to use this module.
Tests
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org.eclipse.jgit.junit
Helpers for unit testing
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org.eclipse.jgit.test
Unit tests for org.eclipse.jgit
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org.eclipse.jgit.java7.test
Unit tests for Java 7 specific features
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org.eclipse.jgit.ant.test
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org.eclipse.jgit.pgm.test
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org.eclipse.jgit.http.test
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org.eclipse.jgit.junit.test
No further description needed
Warnings/Caveats
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Native smbolic links are supported, but only if you are using Java 7 or newer and include the org.eclipse.jgit.java7 jar/bundle in the classpath, provided the file system supports them. For Windows you must have Windows Vista/Windows 2008 or newer, use a non-administrator account and have the SeCreateSymbolicLinkPrivilege.
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Only the timestamp of the index is used by jgit if the index is dirty.
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JGit requires at least a Java 7 JDK.
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CRLF conversion is performed depending on the core.autocrlf setting, however Git for Windows by default stores that setting during installation in the "system wide" configuration file. If Git is not installed, use the global or repository configuration for the core.autocrlf setting.
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The system wide configuration file is located relative to where C Git is installed. Make sure Git can be found via the PATH environment variable. When installing Git for Windows check the "Run Git from the Windows Command Prompt" option. There are other options like Eclipse settings that can be used for pointing out where C Git is installed. Modifying PATH is the recommended option if C Git is installed.
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We try to use the same notation of $HOME as C Git does. On Windows this is often not the same value as the user.home system property.
Package Features
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org.eclipse.jgit/
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Read loose and packed commits, trees, blobs, including deltafied objects.
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Read objects from shared repositories
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Write loose commits, trees, blobs.
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Write blobs from local files or Java InputStreams.
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Read blobs as Java InputStreams.
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Copy trees to local directory, or local directory to a tree.
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Lazily loads objects as necessary.
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Read and write .git/config files.
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Create a new repository.
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Read and write refs, including walking through symrefs.
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Read, update and write the Git index.
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Checkout in dirty working directory if trivial.
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Walk the history from a given set of commits looking for commits introducing changes in files under a specified path.
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Object transport Fetch via ssh, git, http, Amazon S3 and bundles. Push via ssh, git and Amazon S3. JGit does not yet deltify the pushed packs so they may be a lot larger than C Git packs.
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Garbage collection
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Merge
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Rebase
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And much more
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org.eclipse.jgit.pgm/
- Assorted set of command line utilities. Mostly for ad-hoc testing of jgit log, glog, fetch etc.
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org.eclipse.jgit.java7/
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Support for symbolic links.
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Optimizations for reading file system attributes
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org.eclipse.jgit.ant/
- Ant tasks
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org.eclipse.jgit.archive/
- Support for Zip/Tar and other formats
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org.eclipse.http.*/
- HTTP client and server support
Missing Features
There are some missing features:
- gitattributes support
Support
Post question, comments or patches to the jgit-dev@eclipse.org mailing list. You need to be subscribed to post, see here:
https://dev.eclipse.org/mailman/listinfo/jgit-dev
Contributing
See the EGit Contributor Guide:
http://wiki.eclipse.org/EGit/Contributor_Guide
About Git
More information about Git, its repository format, and the canonical C based implementation can be obtained from the Git website: