WW-4223 Uses safe toString method to avoid exception during generating debug info

git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@1534977 13f79535-47bb-0310-9956-ffa450edef68

core/src/main/java/org/apache/struts2/util/AttributeMap.java

@@ -21,15 +21,14 @@
 
 package org.apache.struts2.util;
 
+import org.apache.struts2.ServletActionContext;
+
+import javax.servlet.jsp.PageContext;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
 
-import javax.servlet.jsp.PageContext;
-
-import org.apache.struts2.ServletActionContext;
-
 
 /**
  * A Map that holds 4 levels of scope.
@@ -48,15 +47,12 @@ public class AttributeMap implements Map {
 
     protected static final String UNSUPPORTED = "method makes no sense for a simplified map";
 
-
     Map context;
 
-
     public AttributeMap(Map context) {
         this.context = context;
     }
 
-
     public boolean isEmpty() {
         throw new UnsupportedOperationException(UNSUPPORTED);
     }
@@ -135,4 +131,25 @@ public class AttributeMap implements Map {
     private PageContext getPageContext() {
         return (PageContext) context.get(ServletActionContext.PAGE_CONTEXT);
     }
+
+    @Override
+    public String toString() {
+        return "AttributeMap {" +
+                "request=" + toStringSafe(context.get("request")) +
+                ", session=" +  toStringSafe(context.get("session")) +
+                ", application=" + toStringSafe(context.get("application")) +
+                '}';
+    }
+
+    private String toStringSafe(Object obj) {
+        try {
+            if (obj != null) {
+                return String.valueOf(obj);
+            }
+            return "";
+        } catch (Exception e) {
+            return "Exception thrown: " + e;
+        }
+    }
+
 }

core/src/main/java/org/apache/struts2/util/StrutsUtil.java

@@ -250,6 +250,16 @@ public class StrutsUtil {
         return Integer.toString(anInt);
     }
 
+    public String toStringSafe(Object obj) {
+        try {
+            if (obj != null) {
+                return String.valueOf(obj);
+            }
+            return "";
+        } catch (Exception e) {
+            return "Exception thrown: " + e;
+        }
+    }
 
     static class ResponseWrapper extends HttpServletResponseWrapper {
         StringWriter strout;

core/src/main/resources/template/simple/debug.ftl

@@ -43,7 +43,7 @@
 <p />
 
 <h3>Value Stack Contents</h3>
-<table border="0" cellpadding="2" cellspacing="0" width="400" bgcolor="#DDDDDD">
+<table border="0" cellpadding="2" cellspacing="0" bgcolor="#DDDDDD">
     <tr><th>Object</th><th>Property Name</th><th>Property Value</th></tr>
 
     <#assign index=1>
@@ -65,7 +65,7 @@
 
 <h3>Stack Context</h3>
 <i>These items are available using the #key notation</i>
-<table border="0" cellpadding="2" cellspacing="0" width="400" bgcolor="#DDDDDD">
+<table border="0" cellpadding="2" cellspacing="0" bgcolor="#DDDDDD">
     <tr>
         <th>Key</th><th>Value</th>
     </tr>
@@ -73,9 +73,10 @@
     <#assign index=1>
     <#list stack.context.keySet() as contextKey>
     <tr bgcolor="<#if (index % 2) == 0>#BBBBBB<#else>#CCCCCC</#if>">
-        <td>${contextKey}</td><td><#if stack.context.get(contextKey)??>${stack.context.get(contextKey).toString()?html}<#else>null</#if></td>
+        <td>${contextKey}</td>
+        <td><#if stack.context.get(contextKey)??>${struts.toStringSafe(stack.context.get(contextKey))?html}<#else>null</#if></td>
     </tr>
         <#assign index= index + 1>
     </#list>
 </table>
-</div>
+</div>