How to get getclass().getResource() from a static context?

问题

I have a function where I am trying to load a file to a URL object, because the example project said so.

public class SecureFTP {

    public static void main(String[] args) throws IOException , ClassNotFoundException, SQLException , JSchException, SftpException{
        File file = new File("/home/xxxxx/.ssh/authorized_keys");
        URL keyFileURL = this.getClass().getClassLoader().getResource(file);

I tried using SecureFTP.class.getResource, but it still could not compile it.

I am fairly new to Java, so I know I am doing something wrong.

回答1:

It can't compile because getResource takes a resource name (a String, and not a File) as parameter, in order to load a resource using the class loading mechanism (from the classpath). Using it with a File makes no sense. If you want to open a file, just use a FileInputStream or a FileReader.

See http://docs.oracle.com/javase/6/docs/api/java/lang/ClassLoader.html#getResource%28java.lang.String%29, and include the compiler error message next time you have such a question.

回答2:

The main method is a static method, so trying to access this (= the current Object) will not work. You can replace that line by

URL keyFileURL = SecureFTP.class.getClassLoader().getResource("/home/xxxxx/.ssh/authorized_keys");

回答3:

From: How to call getClass() from a static method in Java?

Just use TheClassName.class instead of getClass().

回答4:

Old question but this hasn't been said yet. You can do this from a static context:

ClassLoader classLoader = ClassLoader.getSystemClassLoader();
classLoader.getResource("filename");

回答5:

SecureFTP.class.getClassLoader().getResource(<<your resource name>>);

Should do the trick!

来源：https://stackoverflow.com/questions/8361947/how-to-get-getclass-getresource-from-a-static-context

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