Java Servlet的标准导入

Question

Java Servlets use usually the following import statements:

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

If I get it right then javax.servlet.* imports everything inside the package. And because .http is a subpackage of .servlet:

Isn't the third statement unnecessary?

import javax.servlet.* should include .http already.

Or is my assumption wrong. Then please correct me.

Answer 1

No, Java don't do that.

Importing javax.servlet.* imports all of the types in the javax.servlet package but not the types declared in javax.servlet.http .

See tutorial (Apparent Hierarchies of Packages section)