Custom plugin can't copy files from jar becaus

2019-04-12 20:40发布

问题:

I am developing a plugin for SonarQube, and part of what it must do is copy files from itself to the SonarQube Server's directory. I am using Apache Commons IO, and have found that FileUtils.copyDirectory works wonderfully (after testing it with a main method).
The trouble comes from trying to get the directory of files that I want to copy from the jar of the plugin itself. I have tried this:

public File getSrcDir() {
    URL inputUrl = getClass().getResource("/images");
    File srcDir = FileUtils.toFile(inputUrl);
    System.out.println(srcDir);
    return srcDir;
}

When I run it in a main method in my IDE (Eclipse), it prints out C:\...\[Project Directory]\target\classes\images But when I install the plugin into SonarQube as a jar folder in Sonar's "plugins" folder, this method prints out null.
I investigated and found that FileUtils.toFile(URL url) will return null if the url argument has a protocol other than "File". So I added this line to my method: System.out.println(inputUrl.getProtocol());
Sure enough, in my IDE the protocol is "file", but when my plugin is installed the protocol is "jar"!

I have spent the last day pouring over Stack Overflow and Google trying to find a way to deal with this, but to no avail.

I am willing to try/refactor anything.

All I want to do is make it so that my plugin copies a directory from within its jar to SonarQube's Server.
How can I do this?

In case it's relevant, here is the directory within my project (I want to copy the "images" folder and everything in it):

[Project Directory]
    |
    +--/src/main/resources
            |
            +--images
                 |
                 +--profiles
                          |
                          +--awards
                          |    |
                          |    +--Award1.png
                          |    |
                          |    +--Award2.png
                          |
                          +--projects
                               |
                               +--default.png

And here is the directory to copy to in the SonarQube server: [SONARQUBE_HOME]/war/sonar-server/images

回答1:

When resource (in this case images or directory) in classpath coming from jar, it is no longer a physical file

You need to modify the code so that it reads those resources from Stream instead of File


See

  • How to read file from classpath from Stream
  • Get a list of resources from classpath directory