我正在尝试根据Adobe网站上的一篇文章编写一个简单的服务层接口（链接显示在代码头中以供参考）。当我尝试基于模板/组件加载页面时，我收到一个错误：方法[methodname]未定义类型[componentname] _jsp。我尝试使用更简单的单行方法，使用public和no访问修饰符，不同的签名和返回类型，将方法移动到调用代码上方，并始终获得相同的结果。如果我注释掉方法名称并将代码作为大括号括起来的块包含，那么它编译好了。这在CQ / AEM v5.6.1中是不可能的，还是我做错了什么？
下面显示了整个代码和异常（为了简单起见，省略了各种实验版本的注释和原始的getPath（...）方法）。提前感谢您的时间。
<%--
apipage component: implements service layer pages
see: http://blogs.adobe.com/contentmanagement/2012/08/19/how-to-integrate-with-other-web-services-without-creating-osgi-packages/
--%><%
%><%@include file="/libs/foundation/global.jsp"%>
<%@page import="org.apache.commons.httpclient.HttpClient,
org.apache.commons.httpclient.params.HttpClientParams,
org.apache.commons.httpclient.DefaultHttpMethodRetryHandler,
org.apache.commons.httpclient.methods.PostMethod,
org.json.JSONObject"
%><%@page session="false" %><%
%><%
if (request.getParameter("action") != null) {
if (request.getParameter("action").equals("getFields") &&
request.getParameter("param1") != null &&
request.getParameter("param2") != null) {
//response.setContentType("application/json");
// out.write(getPath((String)request.getParameter("param1"), (String)request.getParameter("param2"));
String str1 = "param1";
String str2 = "param2";
//out.write(getPath(str1, str2));
int i = doNothing();
}
} else {
response.setContentType("application/json");
out.write("{\"error\":\"error\"}");
}
/*public*/ int doNothing() {
return 1;
}
%>
Error during include of component '/apps/trp/components/layouts/apipage'
Error Message:
org.apache.sling.api.scripting.ScriptEvaluationException: org.apache.sling.scripting.jsp.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: 24 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp
The method doNothing() is undefined for the type apipage_jsp
21: String str1 = "param1";
22: String str2 = "param2";
23: //out.write(getPath(str1, str2));
24: int i = doNothing();
25: }
26: } else {
27: response.setContentType("application/json");
An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp
Syntax error on token "int", new expected
28: out.write("{\"error\":\"error\"}");
29: }
30:
31: /*public*/ int doNothing() {
32: return 1;
33: }
34:
An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp
doNothing cannot be resolved to a type
28: out.write("{\"error\":\"error\"}");
29: }
30:
31: /*public*/ int doNothing() {
32: return 1;
33: }
34:
An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp
Syntax error, insert ";" to complete Statement
28: out.write("{\"error\":\"error\"}");
29: }
30:
31: /*public*/ int doNothing() {
32: return 1;
33: }
34:
An error occurred at line: 32 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp
Void methods cannot return a value
29: }
30:
31: /*public*/ int doNothing() {
32: return 1;
33: }
34:
35: /*
Processing Info:
Page = /content/trp/en/AfrescoAPI
Resource Path = /content/trp/en/AfrescoAPI/jcr:content
Cell = apipage
Cell Search Path = apipage
Component Path = /apps/trp/components/layouts/apipage
Sling Request Progress:
0 (2013-11-14 10:41:01) TIMER_START{Request Processing}
0 (2013-11-14 10:41:01) COMMENT timer_end format is {<elapsed msec>,<timer name>} <optional message>
0 (2013-11-14 10:41:01) LOG Method=GET, PathInfo=/content/trp/en/AfrescoAPI.html
0 (2013-11-14 10:41:01) TIMER_START{ResourceResolution}
0 (2013-11-14 10:41:01) TIMER_END{0,ResourceResolution} URI=/content/trp/en/AfrescoAPI.html resolves to Resource=JcrNodeResource, type=cq:Page, superType=null, path=/content/trp/en/AfrescoAPI
0 (2013-11-14 10:41:01) LOG Resource Path Info: SlingRequestPathInfo: path='/content/trp/en/AfrescoAPI', selectorString='null', extension='html', suffix='null'
0 (2013-11-14 10:41:01) TIMER_START{ServletResolution}
0 (2013-11-14 10:41:01) TIMER_START{resolveServlet(JcrNodeResource, type=cq:Page, superType=null, path=/content/trp/en/AfrescoAPI)}
0 (2013-11-14 10:41:01) TIMER_END{0,resolveServlet(JcrNodeResource, type=cq:Page, superType=null, path=/content/trp/en/AfrescoAPI)} Using servlet /libs/foundation/components/primary/cq/Page/Page.jsp
0 (2013-11-14 10:41:01) TIMER_END{0,ServletResolution} URI=/content/trp/en/AfrescoAPI.html handled by Servlet=/libs/foundation/components/primary/cq/Page/Page.jsp
0 (2013-11-14 10:41:01) LOG Applying Requestfilters
0 (2013-11-14 10:41:01) LOG Calling filter: org.apache.sling.bgservlets.impl.BackgroundServletStarterFilter
0 (2013-11-14 10:41:01) LOG Calling filter: org.apache.sling.i18n.impl.I18NFilter
0 (2013-11-14 10:41:01) LOG Calling filter: org.apache.sling.rewriter.impl.RewriterFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.designimporter.CanvasPageDeleteRequestFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.adobe.cq.history.impl.HistoryRequestFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.WCMRequestFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.adobe.granite.optout.impl.OptOutFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.theme.impl.ThemeResolverFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.foundation.forms.impl.FormsHandlingServlet
0 (2013-11-14 10:41:01) LOG Calling filter: org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.mobile.core.impl.redirect.RedirectFilter
0 (2013-11-14 10:41:01) LOG RedirectFilter did not redirect (MobileUtil.isMobileResource() returns false)
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.warp.TimeWarpFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.AuthoringUIModeServiceImpl
0 (2013-11-14 10:41:01) LOG Applying Componentfilters
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.personalization.impl.TargetComponentFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.WCMComponentFilter
0 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.WCMDebugFilter
0 (2013-11-14 10:41:01) TIMER_START{/libs/foundation/components/primary/cq/Page/Page.jsp#0}
0 (2013-11-14 10:41:01) LOG Including resource JcrNodeResource, type=trp/components/layouts/apipage, superType=null, path=/content/trp/en/AfrescoAPI/jcr:content (SlingRequestPathInfo: path='/content/trp/en/AfrescoAPI/jcr:content', selectorString='null', extension='html', suffix='null')
0 (2013-11-14 10:41:01) TIMER_START{resolveServlet(JcrNodeResource, type=trp/components/layouts/apipage, superType=null, path=/content/trp/en/AfrescoAPI/jcr:content)}
16 (2013-11-14 10:41:01) TIMER_END{16,resolveServlet(JcrNodeResource, type=trp/components/layouts/apipage, superType=null, path=/content/trp/en/AfrescoAPI/jcr:content)} Using servlet /apps/trp/components/layouts/apipage/apipage.jsp
16 (2013-11-14 10:41:01) LOG Applying Includefilters
16 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.personalization.impl.TargetComponentFilter
16 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.WCMComponentFilter
16 (2013-11-14 10:41:01) LOG Calling filter: com.day.cq.wcm.core.impl.WCMDebugFilter
16 (2013-11-14 10:41:01) TIMER_START{/apps/trp/components/layouts/apipage/apipage.jsp#1}
156 (2013-11-14 10:41:01) LOG SCRIPT ERROR: org.apache.sling.scripting.jsp.jasper.JasperException: Unable to compile class for JSP: //An error occurred at line: 24 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp/The method doNothing() is undefined for the type apipage_jsp/21: String str1 = "param1";/22: String str2 = "param2";/23: //out.write(getPath(str1, str2));/24: int i = doNothing();/25: }/26: } else {/27: response.setContentType("application/json");///An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp/Syntax error on token "int", new expected/28: out.write("{\"error\":\"error\"}");/29: }/30: /31: /*public*/ int doNothing() {/32: return 1;/33: }/34: ///An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp/doNothing cannot be resolved to a type/28: out.write("{\"error\":\"error\"}");/29: }/30: /31: /*public*/ int doNothing() {/32: return 1;/33: }/34: ///An error occurred at line: 31 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp/Syntax error, insert ";" to complete Statement/28: out.write("{\"error\":\"error\"}");/29: }/30: /31: /*public*/ int doNothing() {/32: return 1;/33: }/34: ///An error occurred at line: 32 in the jsp file: /apps/trp/components/layouts/apipage/apipage.jsp/Void methods cannot return a value/29: }/30: /31: /*public*/ int doNothing() {/32: return 1;/33: }/34: /35: /*/
156 (2013-11-14 10:41:01) TIMER_END{140,/apps/trp/components/layouts/apipage/apipage.jsp#1}
172 (2013-11-14 10:41:01) LOG Found processor for post processing ProcessorConfiguration: {contentTypes=[text/html],order=-1, active=true, valid=true, processErrorResponse=true, pipeline=(generator=Config(type=htmlparser, config={}), transformers=(Config(type=linkchecker, config={}), Config(type=mobile, config=JcrPropertyMap [node=node /libs/cq/config/rewriter/default/transformer-mobile, values={component-optional=true, jcr:primaryType=nt:unstructured}]), Config(type=mobiledebug, config=JcrPropertyMap [node=node /libs/cq/config/rewriter/default/transformer-mobiledebug, values={component-optional=true, jcr:primaryType=nt:unstructured}]), Config(type=contentsync, config=JcrPropertyMap [node=node /libs/cq/config/rewriter/default/transformer-contentsync, values={component-optional=true, jcr:primaryType=nt:unstructured}]), serializer=Config(type=htmlwriter, config={}))}
172 (2013-11-14 10:41:01) TIMER_END{172,Request Processing} Dumping SlingRequestProgressTracker Entries
答案 0 :(得分：3)
Scriptlets是魔鬼。你永远不应该使用scriptlet。忘记它们甚至存在。学习JSP EL和JSTL。使用MVC框架。
那就是说，这就是为什么你的代码不起作用的原因。 <%和%>内的所有内容都是为JSP生成的servlet的服务方法内部的代码。那么，以下JSP：
<html>
<% System.out.println("hello"); %>
</html>
，如下所示：
public class YourJsp extends JspServlet {
public void jspService(HttpServletRequest request, HttpServletResponse response) {
JspWriter out = createJspWriter(response);
out.println("<html>");
System.out.println("hello");
out.println("</html>");
}
}
您可以推断出上述示例，您的代码将被翻译为类似
的内容 public void jspService(HttpServletRequest request, HttpServletResponse response) {
...
int doNothing() {
return 1;
}
}
因此会在另一个方法中声明一个方法。这将是无效的Java代码，这就是您的JSP无效的原因。
要在JSP中声明方法，需要以下语法（请注意感叹号，这意味着“声明”）：
<%!
int doNothing() {
return 1;
}
%>
上面的代码将是生成的servlet类的一部分，而不是其jspService()方法的一部分。
那说：你不应该在JSP中有scriptlet。更少的方法。这应该是Java源文件。 Scriptlet已经淘汰了10多年。 JSP是视图组件，其唯一的责任应该是从用Java编写的控制器准备的数据生成HTML标记。
答案 1 :(得分：2)
您需要使用声明语法（＆lt;％！...％＆gt;）：
<%!
public int doNothing() {
return 1;
}
%>
<%
int test = doNothing();
%>