Hello, This has always been a problem. And a quick and decent way of solving this is to forget OGNL and write your own implementation. Below listed the code from AppFuse project which essentially creates a tag to expose all the constants.
*package com.company.app.webapp.taglib; import java.lang.reflect.AccessibleObject; import java.lang.reflect.Field; import java.util.HashMap; import java.util.Map; import javax.servlet.jsp.JspException; import javax.servlet.jsp.PageContext; import javax.servlet.jsp.tagext.TagSupport; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.loandukaan.app.Constants; /** * <p>This class is designed to put all the public variables in a class to a * specified scope - designed for exposing a Constants class to Tag * Libraries.</p> * * <p>It is designed to be used as follows: * <pre><tag:constants /></pre> * </p> * * <p>Optional values are "className" (fully qualified) and "scope".</p> * * <p> * <a href="BaseAction.java.html"><i>View Source</i></a> * </p> * * @author <a href="mailto:[EMAIL PROTECTED]">Matt Raible</a> */ public class ConstantsTag extends TagSupport { private static final long serialVersionUID = 3258417209566116146L; private final Log log = LogFactory.getLog(ConstantsTag.class); /** * The class to expose the variables from. */ private String clazz = Constants.class.getName(); /** * The scope to be put the variable in. */ protected String scope; /** * The single variable to expose. */ protected String var; /** * Main method that does processing and exposes Constants in specified scope * @return int * @throws JspException if processing fails */ @Override public int doStartTag() throws JspException { // Using reflection, get the available field names in the class Class c = null; int toScope = PageContext.PAGE_SCOPE; if (scope != null) { toScope = getScope(scope); } try { c = Class.forName(clazz); } catch (ClassNotFoundException cnf) { log.error("ClassNotFound - maybe a typo?"); throw new JspException(cnf.getMessage()); } try { // if var is null, expose all variables if (var == null) { Field[] fields = c.getDeclaredFields(); AccessibleObject.setAccessible(fields, true); for (Field field : fields) { pageContext.setAttribute(field.getName(), field.get(this), toScope); } } else { try { Object value = c.getField(var).get(this); pageContext.setAttribute(c.getField(var).getName(), value, toScope); } catch (NoSuchFieldException nsf) { log.error(nsf.getMessage()); throw new JspException(nsf); } } } catch (IllegalAccessException iae) { log.error("Illegal Access Exception - maybe a classloader issue?"); throw new JspException(iae); } // Continue processing this page return (SKIP_BODY); } public void setClassName(String clazz) { this.clazz = clazz; } public String getClassName() { return this.clazz; } public void setScope(String scope) { this.scope = scope; } public String getScope() { return (this.scope); } public void setVar(String var) { this.var = var; } public String getVar() { return (this.var); } /** * Release all allocated resources. */ public void release() { super.release(); clazz = null; scope = Constants.class.getName(); } /** * Maps lowercase JSP scope names to their PageContext integer constant * values. */ private static final Map<String, Integer> SCOPES = new HashMap<String, Integer>(); /** * Initialize the scope names map and the encode variable */ static { SCOPES.put("page", PageContext.PAGE_SCOPE); SCOPES.put("request", PageContext.REQUEST_SCOPE); SCOPES.put("session", PageContext.SESSION_SCOPE); SCOPES.put("application", PageContext.APPLICATION_SCOPE); } /** * Converts the scope name into its corresponding PageContext constant value. * @param scopeName Can be "page", "request", "session", or "application" in any * case. * @return The constant representing the scope (ie. PageContext.REQUEST_SCOPE). * @throws JspException if the scopeName is not a valid name. */ public int getScope(String scopeName) throws JspException { Integer scope = (Integer) SCOPES.get(scopeName.toLowerCase()); if (scope == null) { throw new JspException("Scope '" + scopeName + "' not a valid option"); } return scope; } } * On Thu, May 1, 2008 at 2:34 PM, ravi_eze <[EMAIL PROTECTED]>wrote: > > hi, > > even this doesnt seem to be working. > > is it possible to load the constant class to the context and then display > it > form there.? or in that case it expects a setters and getters... or some > way > of getting this done.. the code is very bad to read 'cos every time i am > using @com.company.... > > any help??? > > cheers, > ravi > > > > Wes Wannemacher wrote: > > > > Did you try to import your Constants class? > > > > <%@ page import="com.company.Constants" %> > > > > <s:property value="@[EMAIL PROTECTED]" /> > > > > As far as say C.staticconstant1, all I can really say is that the @ > > symbol is how you access static vars/methods in OGNL. > > > > Another choice might be to use regular ol' EL expressions. > > > > -Wes > > > > On Tue, 2008-04-29 at 21:45 -0700, ravi_eze wrote: > >> hi, > >> > >> > >> Does the following work - > >> > >> <s:set name="C" value="@[EMAIL PROTECTED]" /> > >> <s:property value="#C" /> > >> > >> Yes it does. But my requirement is more like i would import the class > >> into > >> some bean/ variable (C) so that i can say C.staticconstant1 etc... but > by > >> the approach mentioned above, i should repeat the @com.company.Constant > >> string always which reduces the readability. Hope this adds some > clarity. > >> Something similar to import.... and then say Constant.... > >> > >> Also, is com.company.Constants.STATIC_CONSTANTS1 a String? > >> > >> Yes its a string. i would be greatful to any further help. > >> > >> > >> cheers, > >> ravi > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > -- > View this message in context: > http://www.nabble.com/Simplified-usage-of%3A%40com.company.Constants.StaticCOnstants-tp16941171p16993179.html > Sent from the Struts - User mailing list archive at Nabble.com. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > -- Thanks Ram
