全局变量

package cn.tedu.servlet;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//@WebServlet("/DemoServlet")//@WebServlet(urlPatterns={"/DemoServlet2"},loadOnStartup=0)多个映射
@WebServlet(urlPatterns = { "/DemoServlet" }, 
initParams = { @WebInitParam(name="name", value = "hello"),
@WebInitParam(name="name2", value = "java") 
}
)
public class DemoServlet extends HttpServlet {
private String fileName;
private String name;
private static final long serialVersionUID = 1L;

public DemoServlet() {
System.out.println("DemoServlet");
}

@Override
public void init() throws ServletException {
// TODO Auto-generated method stub
System.out.println("init()");
// 1.获取servletconfig对象，从配置对象中
ServletConfig config = this.getServletConfig();
// 2.获取属性值得方法
fileName = config.getInitParameter("fileName");
name=config.getInitParameter("name");
System.out.println(fileName);
System.out.println(name);
}

@Override
protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {
// TODO Auto-generated method stub
super.service(arg0, arg1);
}

protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.getWriter().append("Served at: ").append(request.getContextPath()).append(fileName).append(name);
}

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

@Override
public void destroy() {
// TODO Auto-generated method stub
System.out.println("销毁当前方法");
super.destroy();
}

}