servlet得到web应用路径

package context;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 得到web应用路径
 * @author Administrator
 *
 */
public class ContextDemo1 extends HttpServlet {

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

        //1.得到ServletContext对象
//        ServletContext context = this.getServletConfig().getServletContext();
        ServletContext context = this.getServletContext(); // 推荐使用

        //2.得到web应用路径  /day10
        /*
         * web应用路径：
         *     部署到tomcat服务器上运行的web应用名称
         */
        String contextPath = context.getContextPath();
        System.out.println(contextPath);

        /*
         * 案例：应用到请求重定向
         */
        response.sendRedirect(contextPath + "/index.jsp");
    }

}