网页如何防止xss攻击

网页防止xss攻击的方法：

实现过滤器对特殊字符进行转义过滤，例如：

function filter(xss) {  var whiteList = ['h1', 'h2']; // 白名单  var translateMap = { '<': '<', '>': '>' };  return xss.replace(/</?(.*?)>/g, function(str, $1, index, origin) {    console.log($1);    if (whiteList.indexOf($1) >= 0) {      return str;    }    return str.replace(/[<>]/g, function(str) {      return translateMap[str];    });  });}var search = location.search;var query = search.slice(1);var params = query.split('&').map(function(str) {  var list = str.split('=');  var key = list[0];  var val = list[1];  return { key: decodeURIComponent(key), val: decodeURIComponent(val) };});console.log(params);var xss;params.some(function(item) {  xss = item.val;  return true;});console.log(xss);console.log(filter(xss));document.open();document.write(xss);document.write(filter(xss));document.close(); //eg http://127.0.0.1:8080/?xss=<script>alert(1)</script><h1><h2>1233</h2></h1>