0
我試圖使用json對象從jsp文件傳輸數據。getJSON()JavaScript函數未調用
這是我的JavaScript代碼:
// action when item file is clicked
$("li span.file").click(function(){
// get the ID
alert(' Forward the url when clicked WITH ID => ' + $(this).attr('id'));
$.getJSON('BomItemToJSON', function(data) {
alert('entered getJSON()');
$.each(data, function(i, item) {
alert('entered each()');
var id = item.id;
var description = item.description;
alert('description: ' + description);
formObject = document.forms['itemForm'];
formObject.elements['itemId'].value = id;
formObject.elements['itemDescription'].value = description;
alert('done with javascirpt');
});
});
});
這是我的Servlet應該由JavaScript調用:
public class BomItemToJSON extends HttpServlet {
private static final long serialVersionUID = 1L;
@PersistenceContext(unitName = "xxx")
public EntityManager em;
@Resource
UserTransaction utx;
Logger logger = Logger.getLogger(this.getClass().getCanonicalName());
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("bom item to json servlet has been called.");
try {
utx.begin();
} catch (NotSupportedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SystemException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//int id = Integer.parseInt(request.getParameter("id"));
BomHandling bh = new BomHandling(em, utx);
BomItem item = bh.getBomItem(63788);
Gson gson = new Gson();
String json = gson.toJson(item);
System.out.println("Json: " + json);
response.setContentType("text/plain");
response.setCharacterEncoding("UTF-8");
response.getWriter().write(json);
try {
utx.commit();
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (RollbackException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (HeuristicMixedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (HeuristicRollbackException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SystemException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
這是我的web.xml它映射了Servlet :
<servlet>
<display-name>BomItemToJSON</display-name>
<servlet-name>BomItemToJSON</servlet-name>
<servlet-class>com.xxx.servlets.BomItemToJSON</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>BomItemToJSON</servlet-name>
<url-pattern>/BomItemToJSON</url-pattern>
</servlet-mapping>
當我點擊該項目時,我收到警告,提示「點擊時轉發URL」。但似乎沒有調用getJSON()函數。爲什麼?
指定的URL「BomItemToJSON」實際上是否存在?如果是,它會返回什麼?你的JS控制檯有錯誤嗎? – m90 2012-04-17 08:49:06
在任何現代瀏覽器中,打開調試工具並查看「網絡」選項卡或類似內容。您可能會看到一個404錯誤或類似的錯誤,這可能表明URL映射有問題,或者500錯誤,這表明servlet有問題。如果你看不到,你應該看到響應數據,這可能會幫助你弄清楚發生了什麼。 – 2012-04-17 08:50:41
與您的實際問題無關,但您爲什麼要返回帶有內容類型「text/plain」的JSON? JSON的正確內容類型是['application/json'](http://tools.ietf.org/html/rfc4627)。 (我說它是無關的,因爲'getJSON'將忽略內容類型並嘗試將結果解釋爲JSON。但是,當你明確地設置內容類型時,可以正確設置它。) – 2012-04-17 08:51:20