init.js

java结合ajax编写的简易留言本

  var http_request = false;

  function send_request(url)
  {
    //初始化、指定处理函数、发送请求的函数
    http_request = false;
    //开始初始化XMLHttpRequest对象
    if(window.XMLHttpRequest)
    {
      //Mozilla 浏览器
      http_request = new XMLHttpRequest();
      if (http_request.overrideMimeType)
      {
        //设置MiME类别
        http_request.overrideMimeType('text/xml');
      }
    }
    else if (window.ActiveXObject)
    {
      // IE浏览器
      try
      {
        http_request = new ActiveXObject("Msxml2.XMLHTTP");
      }
      catch (e)
      {
        try
        {
          http_request = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {}
      }
    }
    if (!http_request)
    {
      // 异常，创建对象实例失败
      window.alert("不能创建XMLHttpRequest对象实例.");
      return false;
    }
    http_request.onreadystatechange = processRequest;
    // 确定发送请求的方式和URL以及是否同步执行下段代码
    http_request.open("GET", url, true);
    http_request.send(null);
  }

  // 处理返回信息的函数
  function processRequest()
  {
    if (http_request.readyState == 4)
    {
      // 判断对象状态
      if (http_request.status == 200)
      {
        // 信息已经成功返回，开始处理信息
        //initConstants(http_request.responseText);
        //initConstants(http_request.responseXML.documentElement);
        //alert(http_request.responseText);
        initConstants(http_request.responseXML);
      }
      else
      {
        //页面不正常
        alert("您所请求的页面有异常。");
      }
    }
  }

  function initialize()
  {
    //
    //alert("init ok.");
    send_request("boardServlet");
  }

  function initConstants(item)
  {
    //alert("initConstants : " + item);
    //alert(item.getElementsByTagName('constants'));
    //alert(item.getElementsByTagName('constants').text);
    //alert(item.getElementsByTagName('constants')[0]);
    //alert(item.getElementsByTagName('constants')[0].text);
    //alert("end");

    //for(var i in item)
    //{
      //alert(i+":"+item[i]);
      //alert(item);
    //}

    var constants = item.getElementsByTagName("constants")[0];
    //alert(constants);
    //alert(constants.text);
    //alert(constants.value);
    var title = constants.getElementsByTagName("title")[0];
    var copyright = constants.getElementsByTagName("copyright")[0];
    var password = constants.getElementsByTagName("password")[0];
    var imgs = constants.getElementsByTagName('image');
    var infos = constants.getElementsByTagName('info');
	var currentPage = constants.getElementsByTagName("currentpage")[0].text;
	var sum = constants.getElementsByTagName("sum")[0].text;
	var num = constants.getElementsByTagName("num")[0].text;

	var len = infos.length;
    for(var i=0; i<len; i++)
    {
	  document.getElementById("info"+i+"0").style.display="";
	  document.getElementById("info"+i+"1").style.display="";
      //alert(i);
	  //var tmp = document.getElementById("reply0");
	 // alert(tmp.style);
      var id = infos[i].getElementsByTagName('id')[0].text;
      var username = infos[i].getElementsByTagName('username')[0].text;
      var emailmessage = infos[i].getElementsByTagName('emailmessage')[0].text;
      var homepage = infos[i].getElementsByTagName('homepage')[0].text;
      var img = infos[i].getElementsByTagName('img')[0].text;
      var contentformat = infos[i].getElementsByTagName('contentformat')[0].text;
      var dateformat = infos[i].getElementsByTagName('dateformat')[0].text;
      var reply = infos[i].getElementsByTagName('reply')[0].text;

      //var tab = document.getElementById('');
      document.getElementById("contentformat"+i).innerHTML = contentformat.replace(/&lt;/g,"<");
      document.getElementById("username"+i).innerHTML = username.replace(/&lt;/g,"<");
      document.getElementById("img"+i).src = img;
      if(reply=='')
      {
        document.getElementById("reply"+i+"0").style.display="none";
      }
      else
      {
        document.getElementById("reply"+i+"0").style.display="";
        document.getElementById("reply"+i+"1").innerHTML = reply.replace(/&lt;/g,"<");
      }
      document.getElementById("dateformat"+i).innerHTML = dateformat.replace(/&lt;/g,"<");
      document.getElementById("homepage"+i).innerHTML = homepage.replace(/&lt;/g,"<");
      document.getElementById("emailmessage"+i).innerHTML = emailmessage.replace(/&lt;/g,"<");
	  document.getElementById("viewip"+i).setAttribute("href", "viewip.html?id="+id);
	  document.getElementById("reply"+i).setAttribute("href", "javascript:openChild(\"reply.html?id="+id+"\")");
	  document.getElementById("delete"+i).setAttribute("href", "javascript:openChild(\"delete.html?id="+id+"\")");

      //alert();
    }
	for(var i=len; i<6; i++)
	{
	  document.getElementById("info"+i+"0").style.display="none";
	  document.getElementById("info"+i+"1").style.display="none";
	}

    var sel = document.boardForm.img.options;
    for(var i=0; i<imgs.length; i++)
    {
      sel[i] = new Option(imgs[i].text,i);
      //alert(sel[i]);
    }

    //alert(title.text);
    //alert(copyright.text);
    //alert(password.text);
    document.title = title.text;
    document.getElementById('title2').innerText = title.text;
    //alert(copyright.text);
    var tmp = copyright.text;
    tmp = tmp.replace(/&gt;/g,'>');
    tmp = tmp.replace(/&lt;/g,'<');
    //alert(tmp);
    document.getElementById("copyright").innerHTML = tmp;

	if(num>1)
	{
	  document.getElementById("status0").style.display="";
	  document.getElementById("status1").style.display="none";
	  document.getElementById("sum0").innerText = sum;
	  document.getElementById("num").innerText = num;
	  var pageInfo = "";
	  for(var i=0; i<num; i++)
	  {
	    if(i == currentPage)
		{
		  pageInfo += "<font color=\"gray\">第" + (i+1) + "页</font>";
		}
		else
		{
		  pageInfo += "<a href=\"javascript:update('" + i + "')\">第" + (i+1) + "页</a>";
		}
	  }
	  document.getElementById("page").innerHTML = pageInfo;
	}
	else
	{
	  document.getElementById("status0").style.display="none";
	  document.getElementById("status1").style.display="";
	  document.getElementById("sum1").innerText = sum;
	}
  }

  function openChild(url)
  {
	//alert("197|" + url);
    var result = window.showModalDialog(url,window,"dialogWidth:420px;status:no;dialogHeight:350px");
	//alert("199|" + result);
    if(result != null)
	{
	  //alert("202|" + result);
	  //document.getElementById("txt11").value = k;
	  //更新留言
      update_send_request("boardServlet?currentPage=0");
	}
  }