如何在Java 9模块中使用资源 [英] How to work with resources in Java 9 modules

问题描述

我使用gradle和

I built a small (hello world style) java 9 project using gradle and the jigsaw plugin.

对于junit测试，我尝试将某些文件作为资源进行访问，但是classLoader.getResource(filename)无法找到该文件.

For a junit test I tried to access some file as a resource, but classLoader.getResource(filename) is not able to locate the file.

通常，您将文件放置为src/test/resources/foo.txt并以/foo.txt对其进行访问，但是在Java 9中，看起来情况发生了变化，资源也很(类似于类)

Usually you put the file as src/test/resources/foo.txt and access it as /foo.txt, but with Java 9 it looks like things changed and resources are (similar like classes) encapsulated in modules.

我应该在哪里正确放置gradle的资源文件以正确打包?

Where exactly do I have to put the resource file for gradle to package it correctly?

测试之后访问该文件的正确方法是什么?

What is the right way to access that file afterwards in the test?

我忘记阅读什么文档? :)

What is the documentation I forgot to read? :)

更准确地说，我设置了一个小的测试项目. 使用git clone https://github.com/michas2/java_9_resource_test.git，并在更改到该目录之后执行gradle build. (我正在使用gradle 4.6，但这不应该是问题.)

To be more precise I set up a small test project. Use git clone https://github.com/michas2/java_9_resource_test.git and do a gradle build afterwards after changing to that directory. (I'm using gradle 4.6, but that should not be the problem.)

结构如下:

.
├── build.gradle
└── src
    ├── main
    │   └── java
    │       ├── module-info.java
    │       └── resourceTest
    │           └── Main.java
    └── test
        ├── java
        │   └── resourceTest
        │       └── MainTest.java
        └── resources
            └── resourceTest
                └── test.txt

我尝试使用this.getClass().getResource("/resourceTest/test.txt")访问资源，不幸的是，该资源却返回null.

I try to access the resource using this.getClass().getResource("/resourceTest/test.txt"), which unfortunately gives null in return.

推荐答案

这似乎是Gradle的错误.

This appears to be a Gradle bug.

当我使用-i选项运行Gradle时，我看到它为运行程序而执行的实际命令包括以下内容:

When I run Gradle with the -i option, I see that the actual command it’s executing to run your program includes this:

--patch-module resourceTest=/home/vgr/src/java_9_resource_test/build/classes/java/test

如您所见，它包括build/classes目录，但不包括build/resources目录.

As you can see, it’s including the build/classes directory, but not the build/resources directory.

由于构建将类和资源放置在单独的位置，因此无法使用--patch-module.这些类和资源必须一起放在一个文件树或一个.jar文件中.

Since the build places the classes and resources in separate places, there is no way to use --patch-module. The classes and resources must be together, in one file tree or one .jar file.

我不确定org.gradle.java.experimental-jigsaw插件或Gradle本身是否有缺陷.

Whether this is a flaw in the org.gradle.java.experimental-jigsaw plugin, or Gradle itself, I’m not sure.

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