SpEL selection/projection works with Iterable as well

Issue: SPR-13231

spring-expression/src/main/java/org/springframework/expression/spel/ast/Projection.java

@@ -19,7 +19,6 @@ package org.springframework.expression.spel.ast;
 import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -38,6 +37,7 @@ import org.springframework.util.ObjectUtils;
  *
  * @author Andy Clement
  * @author Mark Fisher
+ * @author Juergen Hoeller
  * @since 3.0
  */
 public class Projection extends SpelNodeImpl {
@@ -86,9 +86,10 @@ public class Projection extends SpelNodeImpl {
 			return new ValueRef.TypedValueHolderValueRef(new TypedValue(result), this);  // TODO unable to build correct type descriptor
 		}
 
-		if (operand instanceof Collection || operandIsArray) {
-			Collection<?> data = (operand instanceof Collection ? (Collection<?>) operand :
-					Arrays.asList(ObjectUtils.toObjectArray(operand)));
+		if (operand instanceof Iterable || operandIsArray) {
+			Iterable<?> data = (operand instanceof Iterable ?
+					(Iterable<?>) operand : Arrays.asList(ObjectUtils.toObjectArray(operand)));
+
 			List<Object> result = new ArrayList<Object>();
 			int idx = 0;
 			Class<?> arrayElementType = null;
@@ -108,6 +109,7 @@ public class Projection extends SpelNodeImpl {
 				}
 				idx++;
 			}
+
 			if (operandIsArray) {
 				if (arrayElementType == null) {
 					arrayElementType = Object.class;
@@ -116,10 +118,11 @@ public class Projection extends SpelNodeImpl {
 				System.arraycopy(result.toArray(), 0, resultArray, 0, result.size());
 				return new ValueRef.TypedValueHolderValueRef(new TypedValue(resultArray),this);
 			}
+
 			return new ValueRef.TypedValueHolderValueRef(new TypedValue(result),this);
 		}
 
-		if (operand==null) {
+		if (operand == null) {
 			if (this.nullSafe) {
 				return ValueRef.NullValueRef.INSTANCE;
 			}

spring-expression/src/main/java/org/springframework/expression/spel/ast/Selection.java

@@ -19,7 +19,6 @@ package org.springframework.expression.spel.ast;
 import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -43,6 +42,7 @@ import org.springframework.util.ObjectUtils;
  * @author Andy Clement
  * @author Mark Fisher
  * @author Sam Brannen
+ * @author Juergen Hoeller
  * @since 3.0
  */
 public class Selection extends SpelNodeImpl {
@@ -75,13 +75,14 @@ public class Selection extends SpelNodeImpl {
 	protected ValueRef getValueRef(ExpressionState state) throws EvaluationException {
 		TypedValue op = state.getActiveContextObject();
 		Object operand = op.getValue();
-
 		SpelNodeImpl selectionCriteria = this.children[0];
+
 		if (operand instanceof Map) {
 			Map<?, ?> mapdata = (Map<?, ?>) operand;
 			// TODO don't lose generic info for the new map
 			Map<Object, Object> result = new HashMap<Object, Object>();
 			Object lastKey = null;
+
 			for (Map.Entry<?, ?> entry : mapdata.entrySet()) {
 				try {
 					TypedValue kvPair = new TypedValue(entry);
@@ -108,6 +109,7 @@ public class Selection extends SpelNodeImpl {
 					state.exitScope();
 				}
 			}
+
 			if ((this.variant == FIRST || this.variant == LAST) && result.isEmpty()) {
 				return new ValueRef.TypedValueHolderValueRef(new TypedValue(null), this);
 			}
@@ -122,11 +124,10 @@ public class Selection extends SpelNodeImpl {
 			return new ValueRef.TypedValueHolderValueRef(new TypedValue(result),this);
 		}
 
-		if ((operand instanceof Collection) || ObjectUtils.isArray(operand)) {
-			List<Object> data = new ArrayList<Object>();
-			Collection<?> coll = (operand instanceof Collection ?
-					(Collection<?>) operand : Arrays.asList(ObjectUtils.toObjectArray(operand)));
-			data.addAll(coll);
+		if (operand instanceof Iterable || ObjectUtils.isArray(operand)) {
+			Iterable<?> data = (operand instanceof Iterable ?
+					(Iterable<?>) operand : Arrays.asList(ObjectUtils.toObjectArray(operand)));
+
 			List<Object> result = new ArrayList<Object>();
 			int index = 0;
 			for (Object element : data) {
@@ -154,22 +155,23 @@ public class Selection extends SpelNodeImpl {
 				}
 			}
 
-			if ((this.variant == FIRST || this.variant == LAST) && result.size() == 0) {
+			if ((this.variant == FIRST || this.variant == LAST) && result.isEmpty()) {
 				return ValueRef.NullValueRef.INSTANCE;
 			}
 
 			if (this.variant == LAST) {
-				return new ValueRef.TypedValueHolderValueRef(new TypedValue(result.get(result.size() - 1)),this);
+				return new ValueRef.TypedValueHolderValueRef(new TypedValue(result.get(result.size() - 1)), this);
 			}
 
-			if (operand instanceof Collection) {
-				return new ValueRef.TypedValueHolderValueRef(new TypedValue(result),this);
+			if (operand instanceof Iterable) {
+				return new ValueRef.TypedValueHolderValueRef(new TypedValue(result), this);
 			}
+
 			Class<?> elementType = ClassUtils.resolvePrimitiveIfNecessary(
 					op.getTypeDescriptor().getElementTypeDescriptor().getType());
 			Object resultArray = Array.newInstance(elementType, result.size());
 			System.arraycopy(result.toArray(), 0, resultArray, 0, result.size());
-			return new ValueRef.TypedValueHolderValueRef(new TypedValue(resultArray),this);
+			return new ValueRef.TypedValueHolderValueRef(new TypedValue(resultArray), this);
 		}
 		if (operand == null) {
 			if (this.nullSafe) {

spring-expression/src/test/java/org/springframework/expression/spel/SelectionAndProjectionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.expression.spel;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -37,6 +38,7 @@ import static org.junit.Assert.*;
 /**
  * @author Mark Fisher
  * @author Sam Brannen
+ * @author Juergen Hoeller
  */
 public class SelectionAndProjectionTests {
 
@@ -106,6 +108,21 @@ public class SelectionAndProjectionTests {
 		assertEquals(4, value);
 	}
 
+	@Test
+	public void selectionWithIterable() throws Exception {
+		Expression expression = new SpelExpressionParser().parseRaw("integers.?[#this<5]");
+		EvaluationContext context = new StandardEvaluationContext(new IterableTestBean());
+		Object value = expression.getValue(context);
+		assertTrue(value instanceof List);
+		List<?> list = (List<?>) value;
+		assertEquals(5, list.size());
+		assertEquals(0, list.get(0));
+		assertEquals(1, list.get(1));
+		assertEquals(2, list.get(2));
+		assertEquals(3, list.get(3));
+		assertEquals(4, list.get(4));
+	}
+
 	@Test
 	public void selectionWithArray() throws Exception {
 		Expression expression = new SpelExpressionParser().parseRaw("integers.?[#this<5]");
@@ -242,6 +259,20 @@ public class SelectionAndProjectionTests {
 		assertEquals(7, list.get(2));
 	}
 
+	@Test
+	public void projectionWithIterable() throws Exception {
+		Expression expression = new SpelExpressionParser().parseRaw("#testList.![wrapper.value]");
+		EvaluationContext context = new StandardEvaluationContext();
+		context.setVariable("testList", IntegerTestBean.createIterable());
+		Object value = expression.getValue(context);
+		assertTrue(value instanceof List);
+		List<?> list = (List<?>) value;
+		assertEquals(3, list.size());
+		assertEquals(5, list.get(0));
+		assertEquals(6, list.get(1));
+		assertEquals(7, list.get(2));
+	}
+
 	@Test
 	public void projectionWithArray() throws Exception {
 		Expression expression = new SpelExpressionParser().parseRaw("#testArray.![wrapper.value]");
@@ -258,23 +289,6 @@ public class SelectionAndProjectionTests {
 		assertEquals(new Integer(7), array[2]);
 	}
 
-	static class MapTestBean {
-
-		private final Map<String, String> colors = new TreeMap<String, String>();
-
-		MapTestBean() {
-			// colors.put("black", "schwarz");
-			colors.put("red", "rot");
-			colors.put("brown", "braun");
-			colors.put("blue", "blau");
-			colors.put("yellow", "gelb");
-			colors.put("beige", "beige");
-		}
-
-		public Map<String, String> getColors() {
-			return colors;
-		}
-	}
 
 	static class ListTestBean {
 
@@ -291,6 +305,7 @@ public class SelectionAndProjectionTests {
 		}
 	}
 
+
 	static class SetTestBean {
 
 		private final Set<Integer> integers = new LinkedHashSet<Integer>();
@@ -306,6 +321,28 @@ public class SelectionAndProjectionTests {
 		}
 	}
 
+
+	static class IterableTestBean {
+
+		private final Set<Integer> integers = new LinkedHashSet<Integer>();
+
+		IterableTestBean() {
+			for (int i = 0; i < 10; i++) {
+				integers.add(i);
+			}
+		}
+
+		public Iterable<Integer> getIntegers() {
+			return new Iterable<Integer>() {
+				@Override
+				public Iterator<Integer> iterator() {
+					return integers.iterator();
+				}
+			};
+		}
+	}
+
+
 	static class ArrayTestBean {
 
 		private final int[] ints = new int[10];
@@ -328,6 +365,26 @@ public class SelectionAndProjectionTests {
 		}
 	}
 
+
+	static class MapTestBean {
+
+		private final Map<String, String> colors = new TreeMap<String, String>();
+
+		MapTestBean() {
+			// colors.put("black", "schwarz");
+			colors.put("red", "rot");
+			colors.put("brown", "braun");
+			colors.put("blue", "blau");
+			colors.put("yellow", "gelb");
+			colors.put("beige", "beige");
+		}
+
+		public Map<String, String> getColors() {
+			return colors;
+		}
+	}
+
+
 	static class IntegerTestBean {
 
 		private final IntegerWrapper wrapper;
@@ -356,6 +413,16 @@ public class SelectionAndProjectionTests {
 			return set;
 		}
 
+		static Iterable<IntegerTestBean> createIterable() {
+			final Set<IntegerTestBean> set = createSet();
+			return new Iterable<IntegerTestBean>() {
+				@Override
+				public Iterator<IntegerTestBean> iterator() {
+					return set.iterator();
+				}
+			};
+		}
+
 		static IntegerTestBean[] createArray() {
 			IntegerTestBean[] array = new IntegerTestBean[3];
 			for (int i = 0; i < 3; i++) {
@@ -369,6 +436,7 @@ public class SelectionAndProjectionTests {
 		}
 	}
 
+
 	static class IntegerWrapper {
 
 		private final Number value;