EQ/NE do not fail in case of a Comparable mismatch and apply a specific CharSequence equality check

Issue: SPR-11708
(cherry picked from commit 66bae99)

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -21,22 +21,19 @@
 import org.springframework.expression.spel.support.BooleanTypedValue;
 
 /**
- * Implements equality operator.
+ * Implements the equality operator.
  *
  * @author Andy Clement
  * @since 3.0
  */
 public class OpEQ extends Operator {
 
-
 	public OpEQ(int pos, SpelNodeImpl... operands) {
 		super("==", pos, operands);
 	}
 
-
 	@Override
-	public BooleanTypedValue getValueInternal(ExpressionState state)
-			throws EvaluationException {
+	public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
 		Object left = getLeftOperand().getValueInternal(state).getValue();
 		Object right = getRightOperand().getValueInternal(state).getValue();
 		return BooleanTypedValue.forValue(equalityCheck(state, left, right));

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -24,20 +24,19 @@
 import org.springframework.util.NumberUtils;
 
 /**
- * Implements greater-than operator.
+ * Implements the greater-than operator.
  *
  * @author Andy Clement
+ * @author Juergen Hoeller
  * @author Giovanni Dall'Oglio Risso
  * @since 3.0
  */
 public class OpGT extends Operator {
 
-
 	public OpGT(int pos, SpelNodeImpl... operands) {
 		super(">", pos, operands);
 	}
 
-
 	@Override
 	public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
 		Object left = getLeftOperand().getValueInternal(state).getValue();
@@ -67,6 +66,12 @@ public BooleanTypedValue getValueInternal(ExpressionState state) throws Evaluati
 
 			return BooleanTypedValue.forValue(leftNumber.intValue() > rightNumber.intValue());
 		}
+
+		if (left instanceof CharSequence && right instanceof CharSequence) {
+			left = left.toString();
+			right = right.toString();
+		}
+
 		return BooleanTypedValue.forValue(state.getTypeComparator().compare(left, right) > 0);
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -27,20 +27,18 @@
  * Implements the less-than operator.
  *
  * @author Andy Clement
+ * @author Juergen Hoeller
  * @author Giovanni Dall'Oglio Risso
  * @since 3.0
  */
 public class OpLT extends Operator {
 
-
 	public OpLT(int pos, SpelNodeImpl... operands) {
 		super("<", pos, operands);
 	}
 
-
 	@Override
-	public BooleanTypedValue getValueInternal(ExpressionState state)
-			throws EvaluationException {
+	public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
 		Object left = getLeftOperand().getValueInternal(state).getValue();
 		Object right = getRightOperand().getValueInternal(state).getValue();
 
@@ -68,6 +66,12 @@ public BooleanTypedValue getValueInternal(ExpressionState state)
 
 			return BooleanTypedValue.forValue(leftNumber.intValue() < rightNumber.intValue());
 		}
+
+		if (left instanceof CharSequence && right instanceof CharSequence) {
+			left = left.toString();
+			right = right.toString();
+		}
+
 		return BooleanTypedValue.forValue(state.getTypeComparator().compare(left, right) < 0);
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -28,12 +28,10 @@
  */
 public class OpNE extends Operator {
 
-
 	public OpNE(int pos, SpelNodeImpl... operands) {
 		super("!=", pos, operands);
 	}
 
-
 	@Override
 	public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
 		Object left = getLeftOperand().getValueInternal(state).getValue();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -19,15 +19,17 @@
 import java.math.BigDecimal;
 
 import org.springframework.expression.spel.ExpressionState;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.NumberUtils;
 import org.springframework.util.ObjectUtils;
 
 /**
- * Common supertype for operators that operate on either one or two operands. In the case
- * of multiply or divide there would be two operands, but for unary plus or minus, there
- * is only one.
+ * Common supertype for operators that operate on either one or two operands.
+ * In the case of multiply or divide there would be two operands, but for
+ * unary plus or minus, there is only one.
  *
  * @author Andy Clement
+ * @author Juergen Hoeller
  * @author Giovanni Dall'Oglio Risso
  * @since 3.0
  */
@@ -70,6 +72,7 @@ public String toStringAST() {
 		return sb.toString();
 	}
 
+
 	protected boolean equalityCheck(ExpressionState state, Object left, Object right) {
 		if (left instanceof Number && right instanceof Number) {
 			Number leftNumber = (Number) left;
@@ -96,11 +99,22 @@ protected boolean equalityCheck(ExpressionState state, Object left, Object right
 			return (leftNumber.intValue() == rightNumber.intValue());
 		}
 
-		if (left != null && (left instanceof Comparable)) {
-			return (state.getTypeComparator().compare(left, right) == 0);
+		if (left instanceof CharSequence && right instanceof CharSequence) {
+			return left.toString().equals(right.toString());
+		}
+
+		if (ObjectUtils.nullSafeEquals(left, right)) {
+			return true;
+		}
+
+		if (left instanceof Comparable && right instanceof Comparable) {
+			Class<?> ancestor = ClassUtils.determineCommonAncestor(left.getClass(), right.getClass());
+			if (ancestor != null && Comparable.class.isAssignableFrom(ancestor)) {
+				return (state.getTypeComparator().compare(left, right) == 0);
+			}
 		}
 
-		return ObjectUtils.nullSafeEquals(left, right);
+		return false;
 	}
 
 }