月度归档:2011年06月

如何让Tomcat修改后的端口重新在Eclipse中起效?

当某个端口被占用后,tomcat就会无法启动,我们需要修改tomcatconfserver.xml端口,如由8080修改为8082,但Eclipse中对于这个tomcat的关联端口却仍为8080,
Connector port="8082"…
这时,我们需要作如下操作,打开Eclipse的 windows->Preference->Server->Installed Runtimes,选中我们那个tomcat,将其删除,同时在J2EE试图状态,在Server tab中删除这个server,然后重起eclipse,再重新用 windows->Preference->Server->Installed Runtimes添加tomcat到eclipse即可让eclipse启动tomcat5时用心的端口8082.

作者:豆博草堂

JavaScrip页面搜索

       昨天,做了个页面搜索的功能,觉得在实际开发中应该比较有用,将代码贴出来供大家参考。将下面的代码拷到文本编辑器中,保存为html,用浏览器打开就可看到实际效果。在Opera, firefox, IE6下测试没问题。
    这个功能的处理过程是:在一个div divCont中放入要显示的选项,给要检索的Label中加入了 forSearch="true"属性(这是个自定义属性),代码根据这个属性取得我们要检索的所有的Label(待检索内容为Label中的文本,我们通过innerHTML取得.),然后用我们要查询的字符串与取得的label内的文本进行比对,当找到含有我们要查询的字符串时,将这个Label背景设为绿色,同时记录第一个找到的 label,检索完毕后,将div divCont的滚动条移到第一条检索结果出。
    如何将这个功能推广到checkbox以外其它上面去呢? 根据上面讲解,我们知道,检索依赖的主要是Label的forSearch="true"
属性和这个Label的innerHTML,所以,我们可以对我们要检索的标签加上forSearch="true"属性,将要检索的内容置于该标签内即可。也就是说,这个检索事实是与标签没有关系的。
    在实际项目中应用时,需要将下面要素添加到页面:
        1.header部分的javascript,添加到你的页面的header部分;
        2.name="words11"的文本框,onclick="searchInfor()的button;
        3.待检索内容的容器<div id="divCont" style="border:1pt #BBCCC0 solid;height:232px;width:40%; overflow: auto; position:absolute"></div>, 这个可选,(但推荐加上,可以看起来比较美观点。)主要是为了实现滚动条效果,如果不加,就会取得整个body下面的指定标签;
        4.getCheckBoxText()函数,这个函数可以传入参数,指定要进行检索的标签类型,默认为label,当传入*时,它将认为整个页面(这一块有点不合理,应该是指定的div下面的所有标签才合适,但目前还没有找到比较好的可以快速获取div下面所有子节点的方法,不止第一层的,如果找到了,可以修改getElementsByAttribute的第一行代码来实现.)的所有加forSearch="true"的标签都要检索。
       5.给你要检索的标签中添加forSearch="true"属性;
       6.将最末尾的javascript代码添加到你的页面的最末尾,千万不要放到header部分,负责divCont会取不到。
       7.美化页面:)
   这样,你的页面就可以具有一个页面搜索功能了.在使用过程中,如果有什么新发现,欢迎分享。
 

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta name="generator" content="HTML Tidy for Windows (vers 14 February 2006), see www.w3.org" />
    <title>
      JavaScript Search
    </title>
    <script language="JavaScript" type="text/javascript">
//<![CDATA[
    /**
    * get elements by attribute
    */
    function getElementsByAttribute(oElm, strTagName, strAttributeName, strAttributeValue){
    var arrElements = (strTagName == "*" && document.all)? document.all : oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    var oAttributeValue = (typeof strAttributeValue != "undefined")? new RegExp("(^|s)" + strAttributeValue + "(s|$)") : null;
    var oCurrent;
    var oAttribute;
    for(var i=0; i<arrElements.length; i++){
        oCurrent = arrElements[i];
        oAttribute = oCurrent.getAttribute(strAttributeName);
        if(typeof oAttribute == "string" && oAttribute.length > 0){
            if(typeof strAttributeValue == "undefined" || (oAttributeValue && oAttributeValue.test(oAttribute))){
                arrReturnElements.push(oCurrent);
            }
        }
    }
    return arrReturnElements;
    }
    /**
    * Global variables
    */
    var refA ; /* the referance of container div. */
    var scTop; /* the */
    var hits = new Array(); /* hits' array */
    /**
    * clean input box while there is no query words inputed.
    */
    function cleanInput(ref){
      var sflag = generalForm.sflag.value;
      if(sflag == '
-1'){
         ref.value = "";
      }
    }
    /**
    * reset Label'
backcolor to default: white.
    */
    function resetLableBackcolor(){
       if(hits){
         if(hits.length){
          var len = hits.length;
          for(var j = 0; j < len; j++){
             hits[j].style.backgroundColor = "";
          }
         }
       }
    }
    /*
    * initialize input box
    */
    function initInput(ref){
      if(ref.value != '' && ref.value != "输入选项名查询"){
        generalForm.sflag.value = "1";
      } else {
        generalForm.sflag.value = "-1";
      }
      
      if(ref.value == ''){
         ref.value = "输入选项名查询";
         resetLableBackcolor();
         refA.scrollTop = scTop;
      }
      searchInfor();
    }
    /**
    * get all tests to search by attribute forSearch.
    * @param String tag type
    */
    function getCheckBoxText(){
     var olE = refA;    
     /* get all tests to search by attribute forSearch. */
     var tag = "label";
     if(arguments.length == 1){    
     tag = arguments[0];
        
     }
     var texts = getElementsByAttribute(olE, tag, "forSearch", "true");
     return texts;
    }
    /**
    * execute query , set backgroundcolor of hits to green, move scrollbar to the first hit.
    */
    function searchInfor(){
     var words = generalForm.words11.value;
     /* get all tests to search by attribute forSearch. */
     var texts = getCheckBoxText();
     var firstChk;
     var cnt = 0;
     resetLableBackcolor();
     if(texts){
        if(texts.length){
           var len = texts.length;
           var flag = -1;
           var ref ;
           var textShow = "";
           for(var i = 0; i < len; i++){
               ref = texts[i];
               textShow = ref.innerHTML;
               flag = textShow.indexOf(words);
               if(flag > -1){
             /* set hits' backgroundColor to green. */
                  ref.style.backgroundColor = "#99FF66";
                  cnt = cnt + 1;
                  hits.push(ref);
                  if(cnt == 1){
                     firstChk = i; /* recode the first hit.*/
                  }
               }
           }
        }
     }
     refA.scrollTop = scTop + firstChk*20; /* set scrolltop to show the first hit.*/
    }
    //]]>
    </script>
  </head>
  <body leftmargin="30pt" rightmargin="0" topmargin="0" bottommargin="0">
    <form name="generalForm" id="generalForm">
      <input type="hidden" name="sflag" value="-1" />
      <div width="40%" style="vertical-align:top;overflow:hidden;" >
        <table width="40%" border="0" cellpadding="3" cellspacing="0" class="tableList" bordercolor="#CCCCCC" style="border-collapse:collapse">
          <tr>
            <td width="70%">
       & nbsp;      选项:< br>             </td>
            <td align="right" width="20%">
              <input name="words11" type="text" class="lightfont" value="输入选项名查询" onclick="cleanInput(this);" onblur="initInput(this);" />
            </td>
            <td width="10%">
              <input type="button" value="搜索" onclick="searchInfor();" />
            </td>
          </tr>
        </table>
      </div>
      <div id="divCont" style="border:1pt #BBCCC0 solid;height:232px;width:40%; overflow: auto; position:absolute">
        <table width="97%" border="0" align="left" cellpadding="0" cellspacing="0" bordercolor="white" bgcolor="white">
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk2" value="2" /> <label forsearch="true" for="chk2">选项1</label></nobr>< br>             </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk3" value="3" /> <label forsearch="true" for="chk3">选项2Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk4" value="4" /> <label forsearch="true" for="chk4">选项3Text</label></nobr>< br>             </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk5" value="5" /> <label forsearch="true" for="chk5">Lable 4Text4</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk6" value="6" /> <label forsearch="true" for="chk6">选项 5Text6</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk7" value="7" /> <label forsearch="true" for="chk7">选项 7Text中国</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk8" value="8" /> <label forsearch="true" for="chk8">选项8 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk9" value="9" /> <label forsearch="true" for="chk9">选项9 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk10" value="10" /> <label forsearch="true" for="chk10">选项10 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk11" value="11" /> <label forsearch="true" for="chk11">选项11 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk12" value="12" /> <label forsearch="true" for="chk12">选项12 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk13" value="13" /> <label forsearch="true" for="chk13">选项13 Text7771</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk14" value="14" /> <label forsearch="true" for="chk14">选项14Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk15" value="15" /> <label forsearch="true" for="chk15">选项15Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk16" value="16" /> <label forsearch="true" for="chk16">选项16Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk17" value="17" /> <label forsearch="true" for="chk17">选项17 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk18" value="18" /> <label forsearch="true" for="chk18">Lable18 Text1</label></nobr>
            </td>
          </tr>
          <tr width="97%" rowspan="8" bgcolor="white">
            <td>
              <nobr><input name="chk" type="checkbox" id="chk19" value="19" /> <label forsearch="true" for="chk19">Lable19 Text1</label></nobr>
            </td>
          </tr>
        </table>
      </div><script language="JavaScript" type="text/javascript">
//<![CDATA[
      /* get referance of divContainer by id divCont */
      refA = document.getElementById('
divCont');
      if(refA){
        /* store refA'
s scrollTop */    
        scTop = refA.scrollTop;
      } else {
     refA = document.body;
        scTop = refA.scrollTop;
     }
      //]]>
      </script>
    </form>
  </body>
</html>

 

作者:豆博草堂

sin(18°)与黄金分割

写程序累了,来点数学换换口味:) 想起高中时求sin(18°)的一个方法,感觉挺有意思,写下来与大家分享。通过这个方法可以看出它与黄金分割的关系.

我们构造一个顶角A为36°的等腰三角形△ABC,作角∠B的平分线,交AB于D,并作出∠A的平分线,交底边与E,如下图,
SIN18

则我们有

△ABC∽△BCD,

从而有,

AB/BC = BC/CD,

即有,

BC^2 = AB*CD

所以,BC =AB* (sqrt(5)-1)/2,
由于AE⊥BC, AE为∠A的平分线,所以,

sin(18°) = sin(∠BAE) = AE/AB = (BC/2)/AB

=(1/2)*(BC/AB)
= (sqrt(5)-1)/4 ≈ 0.618/2 = 0.309
也就是说,sin(18°) 为黄金分割的一半。

作者:豆博草堂