如何使用 gradle 强制执行 java 编译器版本？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/28065488/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to enforce a java compiler version with gradle?
提问by fge
In all of my projects, I use gradle and specify the following:
在我的所有项目中，我使用 gradle 并指定以下内容：
sourceCompatibility = "1.7"; // for example
targetCompatibility = "1.7"; // defaults to sourceCompatibility
Now, I have three different versions of the JDK installed, from 1.6 to 1.8. In order to switch from one version to another, I sourceshell files to change PATH, JAVA_HOMEand even JDK_HOME.
现在，我安装了三个不同版本的 JDK，从 1.6 到 1.8。为了从一个版本切换到另一个，我sourceShell文件来改变PATH，JAVA_HOME甚至JDK_HOME。
By accident it can happen that I use the wrong JDK version and I don't want that... Is there a possibility to check that the compiler version is equal to targetCompatibility before attempting any compilation task?
偶然地，可能会发生我使用错误的 JDK 版本而我不想要的情况……在尝试任何编译任务之前，是否有可能检查编译器版本是否等于 targetCompatibility？
采纳答案by JB Nizet
I use the following:
我使用以下内容：
task checkJavaVersion << {
if (!JavaVersion.current().isJava6()) {
String message = "ERROR: Java 1.6 required but " +
JavaVersion.current() +
" found. Change your JAVA_HOME environment variable.";
throw new IllegalStateException(message);
}
}
compileJava.dependsOn checkJavaVersion
回答by fge
Answer to self, and thanks to @JBNizetfor providing the initial solution...
自我回答，感谢@JBNizet提供初始解决方案...
The solution is indeed to use JavaVersion, and it happens that both sourceCompatibilityand targetCompatibilityaccept a JavaVersionas an argument...
该解决方案确实是在使用JavaVersion，并且它发生，无论sourceCompatibility和targetCompatibility接受JavaVersion作为参数...
Therefore the build file has become this:
因此构建文件变成了这样：
def javaVersion = JavaVersion.VERSION_1_7;
sourceCompatibility = javaVersion;
targetCompatibility = javaVersion; // defaults to sourceCompatibility
And then the task:
然后是任务：
task enforceVersion << {
def foundVersion = JavaVersion.current();
if (foundVersion != javaVersion)
throw new IllegalStateException("Wrong Java version; required is "
+ javaVersion + ", but found " + foundVersion);
}
compileJava.dependsOn(enforceVersion);
And it works:
它有效：
$ ./gradlew clean compileJava
:clean UP-TO-DATE
:enforceVersion FAILED
FAILURE: Build failed with an exception.
* Where:
Build file '/home/fge/src/perso/grappa-tracer-backport/build.gradle' line: 55
* What went wrong:
Execution failed for task ':enforceVersion'.
> Wrong Java version; required is 1.7, but found 1.8
回答by codehearts
If you want the version to be checked for all tasks, you can add an assertion in build.gradleto enforce it:
如果您希望检查所有任务的版本，您可以添加一个断言build.gradle来强制执行它：
assert JavaVersion.current().isJava9Compatible(): "Java 9 or newer is required"
With Gradle 5.4.1, the failure looks like this:
使用 Gradle 5.4.1，失败看起来像这样：
$ ./gradlew --quiet build
FAILURE: Build failed with an exception.
* Where:
Build file '/home/codehearts/build.gradle' line: 15
* What went wrong:
A problem occurred evaluating root project 'Codehearts'.
> Java 9 or newer is required. Expression: org.gradle.api.JavaVersion.current().isJava9Compatible()
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 3s
You can also check exact versions if needed:
如果需要，您还可以检查确切的版本：
assert JavaVersion.current().isJava9(): "Java 9 is required"
