Java（JSP）项目的相对路径

Question

I looking for something like of request.getServletContext().getRealPath() to use inside custom class (interceptor in Hibernate, which hasn't access to request object).

File file = new File("/photo/test.txt");
file.delete();

... above code will fail, because the path of file is /lib directory of Tomcat now.

But i need to start count from the project, not Tomcat.

Any ideas?

Answer 1

getRealPath will return the path from the root and beyond.

You should use the context path, instead.

Take a look at this thread

try to use

request.getServletContext().getContextPath();

Answer 2

IMHO the simplest way for you is to get the root of your application in a ServletContextListener declared in web.xml or via a WebListener annotation and to store it in a static variable.

public class RootPathHolder implements ServletContextListener {
    static String rootPath;

    public void contextInitialized(ServletContextEvent sce) {
        RootServletListener.rootPath = sce.getServletContext().getRealPath("/");
    }

    public void contextDestroyed(ServletContextEvent sce) {
    }

    public static String getRootPath() {
        return rootPath;
    }
}

That way you will have access to the root path of your application from anywhere as RootPathHolder.getRootPath() and in your interceptor you will only need to do a path concatenation :

Path realPath = Paths.get(RootPathHolder.getRootPath(), "photo/test.txt");