仍然遇到此问题。如果可以的话请帮忙。
所以我尝试使用 Geocortex IMF 框架修复一段代码。我在第 40 行收到一个错误，该错误基本上是拉出一个空异常。它是java和html的混合体。由于某种原因，我似乎无法找出为什么错误会拉出空值。即使我向变量加载数据，它仍然停在 rs = activeLayer.getRecordset();
这是他们填写并提交的地址表
<%@ page errorPage="imfError.jsp" %>
<%
/*
Program: afoAddressForm.jsp
Purpose: Displays a page to the user to input address values for a
USAddress type of geocoding query.
Usage: </>
History:
*/
String layerId = request.getParameter("layerid");
String scale = request.getParameter("scale");
if (layerId == null) {
throw new Exception("Missing layerid parameter.");
}
if (scale == null) {
throw new Exception("Missing scale parameter.");
}
%>
<jsp:include page="/imfCopyright.jsp"/>
<html>
<head>
<title></title>
<meta http-equiv="Content-Style-Type" content="text/css">
<link href="../../../imfStyle.css" rel="stylesheet" type="text/css">
<script language="JavaScript" type="text/javascript">
function doNothing() {
}
function submitForm() {
var strStreetName = document.frm.streetName.value;
if (strStreetName == "") {
alert("Please enter street name." );
document.frm.streetNumber.focus();
} else {
document.frm.action = "afoAddress.jsp?streetName="+strStreetName;
document.frm.submit();
}
}
</script>
</head>
<body bgcolor="#FFFFFF" alink="#ff0000" link="#ff0000" vlink="#ff0000">
<form name="frm" action="JavaScript:doNothing()" method="post">
<input type="hidden" name="layerid" value="<%= layerId %>">
<input type="hidden" name="scale" value="<%= scale %>">
<table width="95%" border="0" cellspacing="0" cellpadding="0">
<center>
<tr><td align="left" class="bb11">Zoom To Street<hr></td></tr>
<tr><td height="10"></td></tr>
<tr>
<td align="left" valign="top" class="bn8">
Enter the street name where you wish to centre the map.
If matching streets are found, you will be shown a list
of matching street names for you to choose where to
zoom the map to.
</td>
</tr>
<tr><td height="10"></td></tr>
<tr><td align="center" class="bb8">Street Name</td></tr>
<tr><td align="center" class="bb8"><input name="streetName" size="15" maxLength=40 value=""></td></tr>
<tr><td height="10"></td></tr>
<tr><td align="center" ><input name="btn" type="button" value="Submit" onclick="JavaScript:submitForm()"></td></tr>
<tr><td height="10"></td></tr>
</center>
</table>
</form>
</body>
</html>
这是地址表单提交的内容
<%@ page import="com.moximedia.aims.*" %>
<%
/*
Program: imfGeocodeUSAddress.jsp
An Internet Mapping Framework (IMF) system script
Copyright 2002 Province of British Columbia - all rights reserved
Purpose: Displays a page of positions matching the address
input by the user for USAddress geocoding styles.
History: 20020610 Cates: original coding
20030724 Cates: send user selection to separate script for labelling.
20040525 Cates: changed frame reference top to parent
20050103 Cates: added type to stylesheet link.
*/
String layerId = request.getParameter("layerid");
String scale = request.getParameter("scale");
String StreetName = request.getParameter("streetName");
AimsMap map = (AimsMap) (session.getAttribute("map"));
AimsFeatureLayer activeLayer = (AimsFeatureLayer) map.getLayers().getLayer(layerId);
AimsRecordset rs = null;
AimsFilter streetFilter = new AimsFilter();
if (activeLayer != null && activeLayer.getFilter()!= null) {
streetFilter = (AimsFilter) activeLayer.getFilter();
}
String query_String="";
if (StreetName == null) {
return;
}else{
StreetName = StreetName.toUpperCase();
query_String = "upper(FENAME) = '" + StreetName +"'";
//query_String = "FENAME like '%" + StreetName +"%'";
streetFilter.setWhereExpression(query_String);
}
// do the query, and whatever we need to do with the data
rs = activeLayer.getRecordset();
rs.clear();
rs.clearFilter();
rs.setMaximumResults(100);
rs.setBufferSize(rs.getMaximumResults());
rs.setFilter(streetFilter);
rs.query();
int count = 0;
rs.moveFirst();
while(!rs.EOF()) {
count++;
rs.moveNext();
}
%>
<jsp:include page="/imfCopyright.jsp"/>
<html>
<head>
<title></title>
<meta http-equiv="Content-Style-Type" content="text/css">
<link href="imfStyle.css" rel="stylesheet" type="text/css">
<script language="JavaScript" type="text/javascript">
function submitForm() {
document.query.submit();
}
</script>
</head>
<body onload="submitForm();">
<form name="query" method="post" action="afoSelectDefaultFind.jsp">
<input type="hidden" name="layerid" value="<%= layerId%>" >
<input type="hidden" name="rec" value="1" >
<input type="hidden" name="total" value="<%=count%>" >
<input type="hidden" name="query_String" value="<%=query_String%>" >
</form>
</body>
</html>
错误是当您在表单上点击提交时，会弹出 java.lang.NullPointerException 错误并将其放在第 40 行，即 rs = activeLayer.getRecordset();。对此的任何帮助都会很棒。
最佳答案
嗯，我的猜测是 activeLayer 为 null，然后您在 null 对象引用上调用 getRecordset()。你可以尝试调试一下
map.getLayers().getLayer(layerId);
确保它返回一些东西？
关于java - Geocortext IMF框架空引用异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1364249/