Question

我想以树形结构在MySQL中显示数据库。

我有一个JSP页面来获取数据库名称和JavaScript页面以树格式显示它。

由于我是Web应用程序开发的新手，我不知道如何在不使用jQuery的情况下将数据库名称从JSP页面获取到JavaScript页面。我是否需要为此目的使用jQuery？

demoframeset.html

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            font-family:garamond; 
            font-size:12pt;
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            font-weight:bold;
            text-decoration:underline}
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        <!-- If you want the black background, replace the contents  -->
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        <!-- Code for browser detection. DO NOT REMOVE.              -->
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        <!-- Infrastructure code for the TreeView. DO NOT REMOVE.    -->
        <SCRIPT src="ftiens4.js"></SCRIPT>

        <!-- Scripts that define the tree. DO NOT REMOVE.            -->
        <SCRIPT src="demoFramesetNodes.js"></SCRIPT>

    </HEAD>

    <BODY topmargin="16" marginheight="16">

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demoFrameSetNodes.js

  USETEXTLINKS = 1
  STARTALLOPEN = 0
   ICONPATH = ''
  foldersTree = gFld("<i>Databases</i>", "demoFramesetRightFrame.html")
  foldersTree.treeID = "Frameset" 
  aux11 = insFld(foldersTree, gFld("New", "Databases.jsp"))

  var xmlHttp 
 function create()
  { 
      xmlHttp=CreateXmlHttpObject()
      if (xmlHttp==null)
      {
         alert ("Browser does not support HTTP Request")
         return
      } 

       var url="new1.jsp"
      url=url+"?dbname="+str

      url=url+"&sid="+Math.random()
     //  out.print(url)
       xmlHttp.onreadystatechange=stateChanged 
       xmlHttp.open("GET",url,true)
       xmlHttp.send()

   }
  function stateChanged() 
   { 
      if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
      { 
          document.getElementById("div").innerHTML=xmlHttp.responseText 
     } 
  } 
  function CreateXmlHttpObject()
  { 
       var objXMLHttp=null
       if (window.XMLHttpRequest)
       {
              objXMLHttp=new XMLHttpRequest()
         }
          else if (window.ActiveXObject)
         {
          objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
        }
         return objXMLHttp
  }

new1.jsp

try {
    String responseText = "";
    String text = "";
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/", "root", "");

    DatabaseMetaData dbmd = conn.getMetaData();

    ResultSet ctlgs = dbmd.getCatalogs();
    while (ctlgs.next()) {
        text += ctlgs.getString(1) + ",";
    }
} catch (Exception e) {
    out.println(e);
}

Answer 1

您应该能够从请求查询字符串parmaters中检索 dbname 。这可以使用：

完成

request.getParameter("your-param");

在您的情况下，它应该是 dbname 参数，您在JS文件中的URL中注入：

try {
    String dbName = request.getParameter("dbname"); // Retrive the dbname parameter
    String responseText = "";
    String text = "";
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/" + dbName /*Use the dbName in the schema URL*/, "root", "");

    DatabaseMetaData dbmd = conn.getMetaData();

    ResultSet ctlgs = dbmd.getCatalogs();
    while (ctlgs.next()) {
        text += ctlgs.getString(1) + ",";
    }
} catch (Exception e) {
    out.println(e);
}

编辑：

否则，您只需在JSP中显示数据库名称而无需任何外部请求调用，因为您已经将数据库名称填充到逗号分隔的String，您可以使用<c:forTokens>标记迭代你String的分裂数组; 文字：

<c:forTokens items="${text}" delims="," var="dbname"> 
  <c:out value="${dbname}"/><p> 
</c:forTokens>

从JSP页面获取Array值到外部JavaScript页面

1 个答案:

编辑：