JavaWEB（servlet）

一、servlet

先在src里面创建一个servlet包,继承HttpServlet

有doget和dopost方法：

在doget里面调用dopost方法

 
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//		System.out.println("正在处理get请求");
		doPost(req, resp);
	}

dopost方法:

@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//		System.out.println("正在处理post请求");
		//设置编码方式
		req.setCharacterEncoding("utf-8");
		resp.setContentType("text/html;charset=UTF-8");
		//拿session和out和application
		HttpSession session=req.getSession();
		PrintWriter out=resp.getWriter();
		ServletContext application=this.getServletContext();
		
		//拿上下文参数
		String ctxStr=application.getInitParameter("ip");
		System.out.println("上下文参数："+ctxStr);
		//用逗号去分割
		String[] ss=ctxStr.split(",");
		
		//接收表单的值
		String name=req.getParameter("iname");
		String pwd=req.getParameter("ipwd");
		//取初始化参数
		String str=this.getInitParameter("sb");
		System.out.println("初始化参数："+str);
		//假设法
		if("好男人".equals(name)&&"666".equals(pwd)) {
			session.setAttribute("uname", name);
			resp.sendRedirect("success.jsp");
		}
		else {
			out.print("<script>alert('用户名或者密码有误');location.href='login.jsp';</script>");
		}
		
	}

web.xml里面配置和映射：

 <!-- 配置servlet(DLServlet) -->
  <servlet>
  	<servlet-name>dLServlet</servlet-name>
  	<servlet-class>com.zking.servlet.DLServlet</servlet-class>
<!-- 映射servlet(DLServlet) -->
  <servlet-mapping>
  	<servlet-name>dLServlet</servlet-name>
  	<url-pattern>/login.do</url-pattern>
  </servlet-mapping>