Adds support to parse collection of parameters

core/src/main/java/org/apache/struts2/dispatcher/StrutsResultSupport.java

@@ -23,6 +23,8 @@ package org.apache.struts2.dispatcher;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
+import java.util.ArrayList;
+import java.util.Collection;
 
 import org.apache.struts2.StrutsStatics;
 
@@ -195,31 +197,64 @@ public abstract class StrutsResultSupport implements Result, StrutsStatics {
      */
     protected String conditionalParse(String param, ActionInvocation invocation) {
         if (parse && param != null && invocation != null) {
-            return TextParseUtil.translateVariables(param, invocation.getStack(),
-                    new TextParseUtil.ParsedValueEvaluator() {
-                        public Object evaluate(String parsedValue) {
-                            if (encode) {
-                                if (parsedValue != null) {
-                                    try {
-                                        // use UTF-8 as this is the recommended encoding by W3C to
-                                        // avoid incompatibilities.
-                                        return URLEncoder.encode(parsedValue, "UTF-8");
-                                    }
-                                    catch(UnsupportedEncodingException e) {
-                                        if (LOG.isWarnEnabled()) {
-                                            LOG.warn("error while trying to encode ["+parsedValue+"]", e);
-                                        }
-                                    }
-                                }
-                            }
-                            return parsedValue;
-                        }
-            });
+            return TextParseUtil.translateVariables(
+                param, 
+                invocation.getStack(),
+                new EncodingParsedValueEvaluator());
         } else {
             return param;
         }
     }
 
+    /**
+     * As {@link #conditionalParse(String, ActionInvocation)} but does not
+     * convert found object into String. If found object is a collection it is
+     * returned if found object is not a collection it is wrapped in one.
+     * 
+     * @param param
+     * @param invocation
+     * @param excludeEmptyElements
+     * @return
+     */
+    protected Collection<String> conditionalParseCollection(String param, ActionInvocation invocation, boolean excludeEmptyElements) {
+        if (parse && param != null && invocation != null) {
+            return TextParseUtil.translateVariablesCollection(
+                param, 
+                invocation.getStack(),
+                excludeEmptyElements,
+                new EncodingParsedValueEvaluator());
+        } else {
+            Collection<String> collection = new ArrayList<String>(1);
+            collection.add(param);
+            return collection;
+        }
+    }
+
+    /**
+     * {@link com.opensymphony.xwork2.util.TextParseUtil.ParsedValueEvaluator} to do URL encoding for found values. To be
+     * used for single strings or collections.
+     * 
+     */
+    private final class EncodingParsedValueEvaluator implements TextParseUtil.ParsedValueEvaluator {
+        public Object evaluate(String parsedValue) {
+            if (encode) {
+                if (parsedValue != null) {
+                    try {
+                        // use UTF-8 as this is the recommended encoding by W3C to
+                        // avoid incompatibilities.
+                        return URLEncoder.encode(parsedValue, "UTF-8");
+                    }
+                    catch(UnsupportedEncodingException e) {
+                        if (LOG.isWarnEnabled()) {
+                            LOG.warn("error while trying to encode ["+parsedValue+"]", e);
+                        }
+                    }
+                }
+            }
+            return parsedValue;
+        }
+    }
+
     /**
      * Executes the result given a final location (jsp page, action, etc) and the action invocation
      * (the state in which the action was executed). Subclasses must implement this class to handle

core/src/test/java/org/apache/struts2/dispatcher/StrutsResultSupportTest.java

@@ -21,6 +21,9 @@
 
 package org.apache.struts2.dispatcher;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import org.apache.struts2.StrutsInternalTestCase;
 import org.easymock.EasyMock;
 
@@ -109,6 +112,34 @@ public class StrutsResultSupportTest extends StrutsInternalTestCase {
         EasyMock.verify(mockActionInvocation);
     }
 
+    public void testConditionalParseCollection() throws Exception {
+        ValueStack stack = ActionContext.getContext().getValueStack();
+        stack.push(new ActionSupport() {
+            public List<String> getList() {
+                return new ArrayList<String>(){{
+                    add("val 1");
+                    add("val 2");
+                }};
+            }
+        });
+
+        ActionInvocation mockActionInvocation = EasyMock.createNiceMock(ActionInvocation.class);
+        mockActionInvocation.getStack();
+        EasyMock.expectLastCall().andReturn(stack);
+        EasyMock.replay(mockActionInvocation);
+
+        InternalStrutsResultSupport result = new InternalStrutsResultSupport();
+        result.setParse(true);
+        result.setEncode(true);
+
+        Collection<String> collection = result.conditionalParseCollection("${list}", mockActionInvocation, true);
+
+        assertNotNull(collection);
+        assertEquals(2, collection.size());
+        assertTrue(collection.contains("val+1"));
+        assertTrue(collection.contains("val+2"));
+        EasyMock.verify(mockActionInvocation);
+    }
 
     public static class InternalStrutsResultSupport extends StrutsResultSupport {
         private String _internalLocation = null;