运行 JAR 时将外部资源加载到类路径中

Question

I have an application that requires configuration on start-up. However, I can't store this in /resources since every environment that will host this application will be completely different. I want to put this under a directory found via a system property defined in the environment, but for now I want to get an absolute path working - let's say /tr/apps/myFile.txt (where /tr/apps/ is the root of where the application is deployed).

I found a Maven plugin which looked like it would do the job: https://maven.apache.org/surefire/maven-surefire-plugin/examples/configuring-classpath.html

So I added this to my pom:

<build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.0.0-M3</version>
        <configuration>
          <additionalClasspathElements>
            <additionalClasspathElement>/tr/apps</additionalClasspathElement>
          </additionalClasspathElements>
        </configuration>
      </plugin>
    </plugins>
  </build>

Now I have to use the following method to get the file:

InputStream inputStream = Thread.currentThread().getContextClassloader().getResourceAsStream("tr/apps/myFile.txt")
if(inputStream == null) {
    throw new Exception("myFile.txt not found");
}

This exception always seems to be thrown (ie it isn't able to find the file on the classpath). Does anybody know why this is? Or if there is an alternative plugin/solution for this?

Would really appreciate any input!

Answer 1

Did you try looking for the answer in Stackoverflow? It is a common question in Java and the answer is always quite simple (in the end depending even if you are using spring or not).

Try with the solution described here How a JAR file can read an external properties file