谷歌java格式-重新格式化 Java 源代码以符合 Google Java 风格

# google-java-format `google-java-format` is a program that reformats Java source code to comply with [Google Java Style][]. [Google Java Style]: https://google.github.io/styleguide/javaguide.html ## Using the formatter ### from the command-line [Download the formatter](https://github.com/google/google-java-format/releases) and run it with: ``` java -jar /path/to/google-java-format-${GJF_VERSION?}-all-deps.jar <options> [files...] ``` The formatter can act on whole files, on limited lines (`--lines`), on specific offsets (`--offset`), passing through to standard-out (default) or altered in-place (`--replace`). To reformat changed lines in a specific patch, use [`google-java-format-diff.py`](https://github.com/google/google-java-format/blob/master/scripts/google-java-format-diff.py). ***Note:*** *There is no configurability as to the formatter's algorithm for formatting. This is a deliberate design decision to unify our code formatting on a single format.* ### IntelliJ, Android Studio, and other JetBrains IDEs A [google-java-format IntelliJ plugin](https://plugins.jetbrains.com/plugin/8527) is available from the plugin repository. To install it, go to your IDE's settings and select the `Plugins` category. Click the `Marketplace` tab, search for the `google-java-format` plugin, and click the `Install` button. The plugin will be disabled by default. To enable it in the current project, go to `File→Settings...→google-java-format Settings` (or `IntelliJ IDEA→Preferences...→Other Settings→google-java-format Settings` on macOS) and check the `Enable google-java-format` checkbox. (A notification will be presented when you first open a project offering to do this for you.) To enable it by default in new projects, use `File→Other Settings→Default Settings...`. When enabled, it will replace the normal `Reformat Code` and `Optimize Imports` actions. #### IntelliJ JRE Config The google-java-format plugin uses some internal classes that aren't available without extra configuration. To use the plugin, go to `Help→Edit Custom VM Options...` and paste in these lines: ``` --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED ``` Once you've done that, restart the IDE. ### Eclipse The latest version of the `google-java-format` Eclipse plugin can be downloaded from the [releases page](https://github.com/google/google-java-format/releases). Drop it into the Eclipse [drop-ins folder](http://help.eclipse.org/neon/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fp2_dropins_format.html) to activate the plugin. The plugin adds a `google-java-format` formatter implementation that can be configured in `Window > Preferences > Java > Code Style > Formatter > Formatter Implementation`. ### Third-party integrations * Gradle plugins * [spotless](https://github.com/diffplug/spotless/tree/main/plugin-gradle#google-java-format) * [sherter/google-java-format-gradle-plugin](https://github.com/sherter/google-java-format-gradle-plugin) * Apache Maven plugins * [spotless](https://github.com/diffplug/spotless/tree/main/plugin-maven#google-java-format) * [spotify/fmt-maven-plugin](https://github.com/spotify/fmt-maven-plugin) * [talios/googleformatter-maven-plugin](https://github.com/talios/googleformatter-maven-plugin) * [Cosium/maven-git-code-format](https://github.com/Cosium/maven-git-code-format): A maven plugin that automatically deploys google-java-format as a pre-commit git hook. * SBT plugins * [sbt/sbt-java-formatter](https://github.com/sbt/sbt-java-formatter) * [Github Actions](https://github.com/features/actions) * [googlejavaformat-action](https://github.com/axel-op/googlejavaformat-action): Automatically format your Java files when you push on github ### as a library The formatter can be used in software which generates java to output more legible java code. Just include the library in your maven/gradle/etc. configuration. `google-java-format` uses internal javac APIs for parsing Java source. The following JVM flags are required when running on JDK 16 and newer, due to [JEP 396: Strongly Encapsulate JDK Internals by Default](https://openjdk.java.net/jeps/396): ``` --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED ``` #### Maven ```xml <dependency> <groupId>com.google.googlejavaformat</groupId> <artifactId>google-java-format</artifactId> <version>${google-java-format.version}</version> </dependency> ``` #### Gradle ```groovy dependencies { implementation 'com.google.googlejavaformat:google-java-format:$googleJavaFormatVersion' } ``` You can then use the formatter through the `formatSource` methods. E.g. ```java String formattedSource = new Formatter().formatSource(sourceString); ``` or ```java CharSource source = ... CharSink output = ... new Formatter().formatSource(source, output); ``` Your starting point should be the instance methods of `com.google.googlejavaformat.java.Formatter`. ## Building from source ``` mvn install ``` ## Contributing Please see [the contributors guide](CONTRIBUTING.md) for details. ## License ```text Copyright 2015 Google Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ```