如何设置使用--enable-preview从gradle编译并运行标志? [英] how to set the use --enable-preview compile and run flags from gradle?

问题描述

希望在gradle构建中使用Java 14中的records，但得到了:

Looking to use records from Java 14 in a gradle build, but am getting:

thufir@dur:~/NetBeansProjects/FileWatcherHandler$ 
thufir@dur:~/NetBeansProjects/FileWatcherHandler$ gradle clean build

> Task :compileJava FAILED
/home/thufir/NetBeansProjects/FileWatcherHandler/src/main/java/net/bounceme/dur/files/FXOrder.java:3: error: records are a preview feature and are disabled by default.
public record FXOrder(int units) {}
       ^
  (use --enable-preview to enable records)
1 error

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* 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 641ms
2 actionable tasks: 1 executed, 1 up-to-date
thufir@dur:~/NetBeansProjects/FileWatcherHandler$            

使用javac编译看起来不错:

thufir@dur:~/java$ 
thufir@dur:~/java$ ls
FXOrder.java
thufir@dur:~/java$ 
thufir@dur:~/java$ cat FXOrder.java 

public record FXOrder(int units) {}
thufir@dur:~/java$ 
thufir@dur:~/java$ javac --enable-preview -source 14 FXOrder.java 
Note: FXOrder.java uses preview language features.
Note: Recompile with -Xlint:preview for details.
thufir@dur:~/java$ 
thufir@dur:~/java$ ls
FXOrder.class  FXOrder.java
thufir@dur:~/java$ 

如何在以下构建文件中设置那些编译选项:

how to set those compile options in the following build file:

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java project to get you started.
 * For more details take a look at the Java Quickstart chapter in the Gradle
 * User Manual available at https://docs.gradle.org/6.4.1/userguide/tutorial_java_projects.html
 */

plugins {
    // Apply the java plugin to add support for Java
    id 'java'

    // Apply the application plugin to add support for building a CLI application.
    id 'application'
}

repositories {
    // Use jcenter for resolving dependencies.
    // You can declare any Maven/Ivy/file repository here.
    jcenter()
}

dependencies {
    // This dependency is used by the application.
    implementation 'com.google.guava:guava:28.2-jre'

    // Use TestNG framework, also requires calling test.useTestNG() below
    testImplementation 'org.testng:testng:7.1.1'
}

application {
    // Define the main class for the application.
//    mainClassName = 'FileWatcherHandler.App'
    mainClassName = 'net.bounceme.dur.files.App'


}

test {
    // Use TestNG for unit tests
    useTestNG()
}

java版本:

thufir@dur:~/java$ 
thufir@dur:~/java$ gradle --version

------------------------------------------------------------
Gradle 6.4.1
------------------------------------------------------------

Build time:   2020-05-15 19:43:40 UTC
Revision:     1a04183c502614b5c80e33d603074e0b4a2777c5

Kotlin:       1.3.71
Groovy:       2.5.10
Ant:          Apache Ant(TM) version 1.10.7 compiled on September 1 2019
JVM:          14.0.1 (AdoptOpenJDK 14.0.1+7)
OS:           Linux 5.4.0-29-generic amd64

thufir@dur:~/java$ 
thufir@dur:~/java$ java --version
openjdk 14.0.1 2020-04-14
OpenJDK Runtime Environment AdoptOpenJDK (build 14.0.1+7)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 14.0.1+7, mixed mode, sharing)
thufir@dur:~/java$ 
thufir@dur:~/java$ javac --version
javac 14.0.1
thufir@dur:~/java$ 
thufir@dur:~/java$ which java
/home/thufir/.sdkman/candidates/java/current/bin/java
thufir@dur:~/java$ 

推荐答案

要进行此工作，您可以修改compileJava任务并添加此标志.将此添加到您的build.gradle:

To make this work you can modify the compileJava task and add this flag. Add this to your build.gradle :

compileJava {
    options.compilerArgs += ['--enable-preview']
}

这将确保您的代码可以编译.

This will make sure that your code will compile.

如果还有其他需要编译的任务(例如compileTestJava)，则可以为所有类型为JavaCompile的任务启用此标志:

If you have other tasks which require compilation (for example compileTestJava) you can enable this flag for all tasks which have type JavaCompile :

tasks.withType(JavaCompile).all {
    options.compilerArgs += ['--enable-preview']
}

---

要为测试任务启用此标志，您可以执行以下操作:

---

To enable this flag for test tasks you can do the following :

tasks.withType(Test).all {
    jvmArgs += '--enable-preview'
}

---

您还必须确保为将运行您的代码的JVM添加此标志:

---

You also have to make sure to add this flag for the JVM that will run your code :

tasks.withType(JavaExec) {
    jvmArgs += '--enable-preview'
}

在相应的 JEP 中对此进行了描述:

This is described in the corresponding JEP :

希望在程序中使用预览语言功能的开发人员必须在编译器和运行时系统中明确启用它们

Developers who wish to use preview language features in their programs must explicitly enable them in the compiler and the runtime system

这篇关于如何设置使用--enable-preview从gradle编译并运行标志?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！