Why is this an issue?

Hard-coding a URI makes it difficult to test a program for a variety of reasons:

• path literals are not always portable across operating systems
• a given absolute path may not exist in a specific test environment
• a specified Internet URL may not be available when executing the tests
• production environment filesystems usually differ from the development environment

In addition, hard-coded URIs can contain sensitive information, like IP addresses, and they should not be stored in the code.

For all those reasons, a URI should never be hard coded. Instead, it should be replaced by a customizable parameter.

Further, even if the elements of a URI are obtained dynamically, portability can still be limited if the path delimiters are hard-coded.

This rule raises an issue when URIs or path delimiters are hard-coded.

How to fix it

Code examples

Noncompliant code example

public class Foo {
  public Collection<User> listUsers() {
    File userList = new File("/home/mylogin/Dev/users.txt"); // Noncompliant
    Collection<User> users = parse(userList);
    return users;
  }
}

Compliant solution

public class Foo {
  // Configuration is a class that returns customizable properties: it can be mocked to be injected during tests.
  private Configuration config;
  public Foo(Configuration myConfig) {
    this.config = myConfig;
  }
  public Collection<User> listUsers() {
    // Find here the way to get the correct folder, in this case using the Configuration object
    String listingFolder = config.getProperty("myApplication.listingFolder");
    // and use this parameter instead of the hard coded path
    File userList = new File(listingFolder, "users.txt"); // Compliant
    Collection<User> users = parse(userList);
    return users;
  }
}