In Java servlets, the welcome-file-list is used to specify the default web page that will be displayed to a user when they visit a web application. The welcome-file-list is defined in the web.xml file, which is the deployment descriptor for a Java web application.

To specify a welcome-file-list in a web.xml file, you need to add the following code:

<welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

In this example, the welcome-file-list is defined with two welcome files - index.html and index.jsp. If a user visits the root URL of the web application (e.g., http://localhost:8080/myapp/), the server will look for the welcome files specified in the welcome-file-list in the order they are listed. If the first file (index.html in this case) is not found, the server will try the second file (index.jsp).

It's important to note that the welcome-file-list is optional, and if it is not defined, the server will typically use a default file (such as index.html) as the welcome file.