CSS优先级算法如何计算

CSS优先级算法如何计算,第1张

优先级就近原则,同权情况下样式定义为租肆最近者为准

载入样式以最后载入的定位为准(后写的样式优先级高,前数岁提是大家的权重一样)

1、!important权值最高。

2、弊毕轿内联样式表的权值为 1000。

3、ID 选择器的权值为 100。

4、Class 类选择器的权值为 10。

5、HTML 标签(类型)选择器的权值为 1。

你的传值方法用反了,你上面的<form>表单里面写的方法是post但是你在后台Servlet处理的时候用的是doGet方法处理,是不可能接受到数据的。做这个上传东西的话,需要导入物信团一些外包,像cosFir这种包来实现比较好一点。

如果只是实现提交功能的话,首先思路要明确,你表单的内容提交过来,要直接获取的话用你的方法就可以了,但是注意传值的方法,一般用post传值,因为get方法传值太小,容易丢失数据。还有就是你传过来了在servlet处理的时候最后弄个标记来处理,这样可以利用if分支来处理多个页面出来的的请求,当然servlet也只是初步的处理,你最后还得调用javabean来处理,就是你要用一个业务类来专门处理你的sql语句接串,然后提交数据可处理。看一下我写的一个登录的小程序:

登录页面:index.jsp

<%@ page language="坦返java" import="java.util.*" pageEncoding="GBK"%>

<%

String path = request.getContextPath()

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>My JSP 'index.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control"罩橘 content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<!--

<link rel="stylesheet" type="text/css" href="styles.css">

-->

</head>

<body>

<%

request.setCharacterEncoding("gbk")

String rs_flag=(String)request.getAttribute("rs_flag")

if(rs_flag!=null){

out.println(rs_flag)

}

%>

请登陆:

<form action="LoginServlet" name="form1" method="post">

用户名:<input type="text" name="consumername" >

密码:<input type="password" name="consumerpsw">

<input type="submit" name="sub" value="登陆">

</form>

</body>

</html>

servlet处理Loginservlet

package com.icss.contr

import java.io.IOException

import java.sql.SQLException

import javax.servlet.ServletException

import javax.servlet.http.HttpServlet

import javax.servlet.http.HttpServletRequest

import javax.servlet.http.HttpServletResponse

import com.icss.dao.UserDao

public class LoginServlet extends HttpServlet {

/**

* Constructor of the object.

*/

public LoginServlet() {

super()

}

/**

* Destruction of the servlet. <br>

*/

public void destroy() {

super.destroy()// Just puts "destroy" string in log

// Put your code here

}

/**

* The doGet method of the servlet. <br>

*

* This method is called when a form has its tag value method equals to get.

*

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

*/

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request,response)

}

/**

* The doPost method of the servlet. <br>

*

* This method is called when a form has its tag value method equals to post.

*

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

*/

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

/*

* servlet要完成用户提交信息的整理

*

*/

request.setCharacterEncoding("GBK")

String consumername=request.getParameter("consumername")

String consumerpsw=request.getParameter("consumerpsw")

int flag=0

/*

* servlet要控制请求由那个业务类处理

*/

UserDao userdao=new UserDao()

try {

flag=userdao.validate(consumername, consumerpsw)

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace()

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace()

}

/*

* servlet 要根据业务类处理的结果(判断分支)选择响应的jsp页面

*/

if(flag==0){

/*

* 在响应之前在做显示信息的准备

*/

String rs_flag="登陆失败!请重试!"

request.setAttribute("rs_flag",rs_flag)

//转发

request.getRequestDispatcher("index.jsp").forward(request,response)

}else{

request.getRequestDispatcher("main.jsp").forward(request,response)

}

}

/**

* Initialization of the servlet. <br>

*

* @throws ServletException if an error occurs

*/

public void init() throws ServletException {

// Put your code here

}

}

然后调用javabean业务处理类Userdao来处理

package com.icss.dao

import java.sql.ResultSet

import java.sql.SQLException

import java.util.ArrayList

import java.util.HashMap

import java.util.List

import java.util.Map

import com.icss.base.DbCon

import com.icss.vo.UserVo

public class UserDao extends DbCon {

public int validate(String consumername,String consumerpsw) throws ClassNotFoundException, SQLException{

getCon()

String sql="select * from consumer where consumername='"+consumername+"' and consumerpsw='"+consumerpsw+"'"

int flag=0

ResultSet rs=DbCon.st.executeQuery(sql)

if(rs.next()){

flag=1

}

rs.close()

closeCon()

return flag

}

}

处理完数据库的接串以及查询以后返回结果到servlet做处理,然后返回jsp页面就可以了。

下面这个是连接数据库的,我不知道你用什么数据库,我用的是oracle,不过都差不多,你看一下把:

package com.icss.base

import java.sql.Connection

import java.sql.DriverManager

import java.sql.SQLException

import java.sql.Statement

public class DbCon {

public static Connection conn=null

public static Statement st=null

public void getCon() throws ClassNotFoundException, SQLException{

Class.forName("oracle.jdbc.driver.OracleDriver")//创建数据库驱动对象

conn=DriverManager.getConnection("jdbc:oracle:thin:@192.168.0.207:1521:ICSS","TEST","MANAGER")//创建数据库连接对象

st=conn.createStatement()//创建执行sql语句对象

}

public void closeCon() throws SQLException{

if(st!=null){

st.close()

}

if(conn!=null){

conn.close()

}

}

/**

* @param args

*/

public static void main(String[] args) {

DbCon dbc=new DbCon()

try {

dbc.getCon()

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace()

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace()

}

}

}

呼呼,写这个真是有点浪费时间~·不过好歹完工了,当作是复习一下。希望对你有用。。


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原文地址: http://outofmemory.cn/yw/12261130.html

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