以下是一个简单的例子，演示了如何在JSP页面中使用JavaScript调用Servlet实例：

1. 创建一个名为`HelloServlet.java`的Servlet类，该类继承自`HttpServlet`并重写`doGet`方法：

```java

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class HelloServlet extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

response.setContentType("