Question

我使用AJAX异步填充列表。加载网页后，会触发一个填充列表框的AJAX请求。但是当我将此请求发送到服务器时，将返回一个非预期的网页（存在列表框），而不是列表数据（JSON）。

[成分]
haveList.jsp =有列表框。它包含<script src="loadData.js">标记 loadData.js =它生成一个Ajax请求并将其发送到服务器。加载haveList.jsp后，将调用loadData.js。（我只是检查请求使用alert从服务器获取正确的数据。） returnPage.java =转发到haveList.jsp的Servlet returnJsonData.java =返回loadData.js要求的json字符串的Servlet。
每个都显示如下。

[web.xml中]

<servlet>
<servlet-name>ReturnPage</servlet-name>
<servlet-class>pkg.ReturnPage</servlet-class>    
</servlet>
<servlet-mapping>
<servlet-name>ReturnPage</servlet-name>
<url-pattern>/openHaveList.do</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>DataManager</servlet-name>
<servlet-class>pkg.ReturnJsonData</servlet-class>    
</servlet>
<servlet-mapping>
<servlet-name>DataManager</servlet-name>
<url-pattern>/requestListData.do</url-pattern>
</servlet-mapping>

[现象]
我发送了＃34; openHaveList.do＆＃34;到服务器 Page＆＃34; haveList＆＃34;返回。
立即发生了一个AJAX请求以获取JSON数据。（requestListData.do）（请参阅下面的loadData.js）
使用alert()我检查了服务器的responseText内容我期待JSON数据，但haveList.jsp的HTML就在那里。

[线索]
（1）当我从服务器获得非预期的html时，浏览器的地址栏显示http://localhost/openHaveList.do （在其他页面中，我点击图像。然后openHaveList.do发生。）
（2）当我使用ZAP（Zed攻击代理）捕获请求/响应时，我看到 2 请求发生。
第一个：requestListData.do（响应：空）
第二个：openHaveList.do。（响应：hasList.jsp的html）
因此，我怀疑AJAX请求是无意中重定向的。（requestListData.do - ＆gt; openHaveList.do）

- 来源代码 -
的 [haveList.jsp]
没什么特别的。列表框

[loadData.js]

( function () {
var conn=null, addEvent=null, createXHR=null, loadNations = null, setAsyncLoad=null; 
addEvent = (function(window){
if(window.addEventListener){
   return function (element, eventName, callback, canCapture) {
     element.addEventListener(eventName, callback, canCapture);
 };
  } else if(window.attachEvent){
 return function (element, eventName, callback) {
 element.attachEvent("on" + eventName, callback);
 };
} else {
return function (element, eventName, callback) {
   element["on" + eventName] = callback;
  }
 }
 }(window));
 createXHR = function () {
 var xhrObj = null;
   try{
   xhrObj = new XMLHttpRequest();
  } catch (exception){
    try{
   xhrObj = new ActiveXObject('Msxml2.XMLHTTP');
 } catch (innerException){
  xhrObj = new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
 return xhrObj;
 }; 
  loadAsync = function () {
 var list = document.getElementById("list");   
  conn = createXHR();
  conn.onreadystatechange = function () {
  if(conn.readyState == 4){
     if(conn.status == 200){
        alert(conn.responseText);  //--> Here it shows the html of haveList.jsp
     }
  }
};
conn.open('GET', 'requestListData.do');  
 conn.send();  
 };
 addEvent(window, 'load', function () { loadAsync(); } , false); 
} () );

[returnPage.java]

public class ReturnPage extends HttpServlet {
private static String page = "/haveList.jsp";
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
RequestDispatcher dispatcher = request.getRequestDispatcher(page);
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.addHeader("Cache-Control", "no-store");
response.setDateHeader("Expires", 1L);
dispatcher.forward(request, response); 
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
RequestDispatcher dispatcher = request.getRequestDispatcher(page);
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.addHeader("Cache-Control", "no-store");
response.setDateHeader("Expires", 1L);  
dispatcher.forward(request, response); 
}
}

[returnJsonData.java]

public class ReturnJsonData extends HttpServlet {
private String command = null; 
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
strUri = request.getRequestURI();
command = strUri.substring(request.getContextPath().length());
try {
    response.setHeader("Pragma", "No-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.addHeader("Cache-Control", "no-store");
    response.setDateHeader("Expires", 1L);
    response.setContentType("application/json; charset=UTF-8" );
    response.getWriter().print( loadListData(request, command) );
} catch (Throwable e) {
  System.out.println("Failed to load list");
} 
}  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
strUri = request.getRequestURI();
command = strUri.substring(request.getContextPath().length()); 
try {
   response.setHeader("Pragma", "No-cache");
   response.setHeader("Cache-Control", "no-cache");
   response.addHeader("Cache-Control", "no-store");
   response.setDateHeader("Expires", 1L);
   response.setContentType("application/json; charset=UTF-8" );
   response.getWriter().print( loadListData(request, command) );
 } catch (Throwable e) {
   System.out.println("Failed to load list");
 }  
 } 
private String loadListData(HttpServletRequest request, String command) throws Throwable 
{
String codeList = null;  
if("/requestListData.do".equals(command)){
   codeList = codeDao.select(conn);   
}
}
}

Answer 1

我解决了!! ^^

<强> [原因]
由于我的过滤器。

<强> [详细]
实际上，haveList.jsp是登录页面。我有一个过滤器，用于检查请求是否已登录。如果没有，该过滤器会将请求重定向到“hasList.jsp（登录页面）”。
当触发对服务器（requestListData.do）的ajax调用时，将重定向的请求过滤到登录页面，因为它没有登录。请参阅以下web.xml（之前）。

<filter>
<filter-name>Checker</filter-name>
<filter-class>filter.Checker</filter-class>
<init-param>
<param-name>escape</param-name>
<param-value>/Test/,/Test/gate.jsp,/Test/openHaveList.do</param-value>
</init-param>   
</filter>
<filter-mapping>
<filter-name>Checker</filter-name>
<url-pattern>*.do</url-pattern> 
</filter-mapping>
<filter-mapping>
<filter-name>Checker</filter-name>
<url-pattern>*.jsp</url-pattern>    
</filter-mapping>

<强> [解决]
我将ajax调用注册到服务器作为例外。（转义参数）在我的过滤器 servlet中，我不会将此类异常重定向到登录页面以编程方式。请参阅以下web.xml（之后）。

<filter>
<filter-name>Checker</filter-name>
<filter-class>filter.Checker</filter-class>
<init-param>
<param-name>escape</param-name>
<param-value>/Test/,/Test/gate.jsp,/Test/openHaveList.do,"/requestListData.do"</param-value>
</init-param>   
</filter>
<filter-mapping>
<filter-name>Checker</filter-name>
<url-pattern>*.do</url-pattern> 
</filter-mapping>
<filter-mapping>
<filter-name>Checker</filter-name>
<url-pattern>*.jsp</url-pattern>    
</filter-mapping>

在此之后，我从服务器获取了JSON数据。 ^^

AJAX，send（）似乎无意中被重定向

1 个答案: