如何访问JAR文件中的Maven资源? [英] How to access Maven resources in JAR file?

问题描述

我有一个用Maven构建的Java应用程序.我有一个资源文件夹com/pkg/resources/...，我需要从中访问文件.例如directory.txt.我一直在看各种教程和其他SO答案，但似乎没有一个适合我.现在我有:

I have a Java application that I build with Maven. I have a resources folder com/pkg/resources/... that I need to access files from. For example directory.txt. I've been looking at various tutorials and other SO answers, but none seem to work for me. Right now I have:

ClassLoader classLoader = getClass.getClassLoader();
File file = new File(classLoader.getResource("/directory.txt");

当我输出f.length时，我得到0字节的结果.我也尝试过:

When I output f.length I get a result of 0 bytes. I've also tried:

InputStream is = (this.getClass().getClassLoader().getResourceAsStream("/directory.txt"));
try{
    File file = File.createTempFile("dir", ".txt");
    Files.copy(is, file.toPath());
} catch (IOException e) {
    e.printStackTrace();
}

但是该代码也不起作用.我以前从未使用过从JAR访问文件.关于可能出什么问题的任何想法?

But that code does not work either. I haven't worked with accessing files from a JAR before. Any ideas on what might be going wrong?

推荐答案

首先，使用"src/main/resources"文件夹，例如在资源中，您可以拥有一个名为dummy.txt的文件

First, use the "src/main/resources" folder, for example in resources you can have a file named: dummy.txt

完整路径应为:src/main/resources/dummy.txt

Full path should be: src/main/resources/dummy.txt

在某些课程中，您可以按照以下方式读取dummy.txt:

In some class you could read dummy.txt as folow:

String dummy = new String(IOUtils.toByteArray(this.getClass().getClassLoader().getResourceAsStream("/dummy.txt")));

此外，如果您想在其中放置文件夹，也可以使用它.例如:

Also, if you want to have folders in there you can have it. For example:

src/main/resources/com/pkg/resources/dummy.txt

src/main/resources/com/pkg/resources/dummy.txt

String dummy = new String(IOUtils.toByteArray(this.getClass().getClassLoader().getResourceAsStream("/com/pkg/resources/dummy.txt")));

请考虑在此示例中，我们对pom.xml中的类路径信息没有做任何事情

Have as consideration that in this example we are not doing nothing with the classpath information in our pom.xml

注意:IOUtils来自commons-io，例如:

Note: IOUtils is from commons-io , for example:

<dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId> 
            <version>2.4</version>
</dependency>

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