【发布时间】：2016-09-02 20:18:07
【问题描述】：
我有一个 jsp 页面，它从数据库中读取数据并使用本地主机上的 tomcat 服务器显示它。我被要求将 jsp 转换为 Json 对象。我该怎么做？
我是 jsp 的新手。这是jsp页面供参考。
<%@ page import="x.VoltDAOImpl" %>
<%@ page import="java.util.*" %>
<%@ page import = "java.text.DecimalFormat" %>
<html>
<head>
<title>Data Platform - Real Time Monitor </title>
</head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<link href="/common/default.css" rel="stylesheet" type="text/css" />
<%!
VoltDAOImpl voltDao = new VoltDAOImpl();
DecimalFormat df1 = new DecimalFormat("##,##,##,##,##,##,###");
DecimalFormat df2 = new DecimalFormat("#,###,##0.00");
DecimalFormat df3 = new DecimalFormat("#,###,##0.0000");
%>
<script src="sorttable.js"></script>
<body>
<center>
<div style="font-style:bold;font-size:30;color:black"> Data Platform - Monitor </div>
<%
try{
%>
<%
String client_acronym = request.getParameter("client_acronym");
String algo = request.getParameter("algo");
String listid = request.getParameter("listid");
String sort_by = request.getParameter("sort_by");
%>
<%
Map<String , List<HashMap<String,String>>> returnList= null;
List<HashMap<String,String>> orderDetailsList1= null;
List<HashMap<String,String>> totalSlpSummaryList= null;
List<HashMap<String,String>> totalSlpSummaryBySideList= null;
if( ("".equals(client_acronym)||client_acronym==null ) )
{
}
else if ( (!"".equals(client_acronym) && client_acronym != null ) && (!"".equals(algo) && algo != null ) && (!"".equals(listid) && listid != null ) )
{
long start= System.currentTimeMillis();
long start1= System.currentTimeMillis();
returnList= voltDao.getOrderDetails("PEAKM",algo,listid,voltDao.client,sort_by,1000);
long end= System.currentTimeMillis();
long time_taken=(end-start)/1000;
orderDetailsList1 = returnList.get("order_details");
totalSlpSummaryList = returnList.get("total_slp_summary");
totalSlpSummaryBySideList = returnList.get("total_slp_summary_by_side");
System.out.println( "Took "+time_taken+"secs and got "+orderDetailsList1.size()+" rows" );
}
else if ( (!"".equals(client_acronym) && client_acronym != null) && (!"".equals(algo) && algo != null ) )
{
long start= System.currentTimeMillis();
long start1= System.currentTimeMillis();
returnList= voltDao.getOrderDetails("PEAKM",algo,"",voltDao.client,sort_by,1000);
long end= System.currentTimeMillis();
long time_taken=(end-start)/1000;
orderDetailsList1 = returnList.get("order_details");
totalSlpSummaryList = returnList.get("total_slp_summary");
totalSlpSummaryBySideList = returnList.get("total_slp_summary_by_side");
System.out.println( "Took "+time_taken+"secs and got "+orderDetailsList1.size()+" rows" );
}
else if ( (!"".equals(client_acronym) && client_acronym != null ) )
{
long start= System.currentTimeMillis();
long start1= System.currentTimeMillis();
returnList= voltDao.getOrderDetails("PEAKM",algo,"",voltDao.client,sort_by,1000);
long end= System.currentTimeMillis();
long time_taken=(end-start)/1000;
orderDetailsList1 = returnList.get("order_details");
totalSlpSummaryList = returnList.get("total_slp_summary");
totalSlpSummaryBySideList = returnList.get("total_slp_summary_by_side");
System.out.println( "Took "+time_taken+"secs and got "+orderDetailsList1.size()+" rows" );
}
else
{
}
JSONObject jsonObject = new JSONObject(orderDetailsList1);
JSONObject jsonObject1 = new JSONObject(totalSlpSummaryList);
JSONObject jsonObject2 = new JSONObject(totalSlpSummaryBySideList);
HashMap<String,String> totalSlpSummaryMap = totalSlpSummaryList.get(0);
HashMap<String,String> totalSlpSummaryBySideMap = totalSlpSummaryBySideList.get(0);
if( !("".equals(client_acronym)||client_acronym==null ) )
{
/* out.println( "<table class=\"sortable\" border=\"1\" > ");
out.println(" <tr BGCOLOR = \"#99CCFF\"> <th><p><b>Side </b><p></th> ");
out.println("<th><p><b>Order Qty</b><p></th> ");
String total_ord_qty_buy = totalSlpSummaryBySideMap.get("total_ord_qty_buy");
String total_ord_qty_sell = totalSlpSummaryBySideMap.get("total_ord_qty_sell");
String total_ord_qty = totalSlpSummaryMap.get("total_ord_qty");
try { total_ord_qty_buy = df1.format(Double.parseDouble(total_ord_qty_buy)) ; } catch(Exception e){System.out.println( " could not convert "+total_ord_qty_buy ); }
try { total_ord_qty_sell = df1.format(Double.parseDouble(total_ord_qty_sell)) ; } catch(Exception e){System.out.println( " could not convert "+total_ord_qty_sell ); }
try { total_ord_qty = df1.format(Double.parseDouble(total_ord_qty)) ; } catch(Exception e){System.out.println( " could not convert "+total_ord_qty ); }
out.println("<tr><td><p>Buy</p></td>");
out.println("<td align=\"right\"><p>"+ total_ord_qty_buy +"</p></td>");
out.println("<tr><td><p>Sell </p></td>");
out.println("<td align=\"right\"><p>"+ total_ord_qty_sell +"</p></td>");
out.println("<tr><td><b><p>Total </p></b></td>");
out.println("<td align=\"right\"><b><p>"+ total_ord_qty +"</p></b></td>");
out.println("</table><BR> "); */
int i=0;
out.println( "<table class=\"sortable\" border=\"1\" > ");
out.println(" <tr BGCOLOR = \"#99CCFF\"> ");
out.println("<th><p><b>CLIENT</b><p></th> ");
out.println("<th><p><b>ORD Qty</b><p></th> ");
out.println("</tr>");
for(HashMap<String,String> map : orderDetailsList1)
{
if(i%2==0)
out.println("<tr>");
else
out.println("<tr class=\"alternateRow\">");
String CLIENT_ACRONYM = (map.get("CLIENT_ACRONYM") != null) ? map.get("CLIENT_ACRONYM"): "---";
String ORDER_QTY = ( !("0E-12".equals(map.get("ORDER_QTY"))) ) ? map.get("ORDER_QTY"): "---";
out.println("<td><p>"+ CLIENT_ACRONYM +"</p></td>");
out.println("<td align=\"right\"><p>"+ df1.format(Double.parseDouble(ORDER_QTY)) +"</p></td>");
out.println("</tr>");
i++;
}
out.println("</table>");
}
} catch(Exception e){System.out.println( " error in detail" ); }
%>
</body>
</html>
【问题讨论】：
-
有几个第三方库可用于将 POJO 转换为 JSON 或仅生成 JSON。看这个MKYONG教程，或者使用可以使用GSON、jackson等...
-
您不会将 页面 转换为 Json。您可以将对象输出为 Json。
-
@developerwjk 你能告诉我该怎么做吗？