Make EvaluationException more informative

Update EvaluationException to expose the toDetailedString() method as
the exception message. The simple message can now be accessed via the
new getSimpleMessage() method.

Issue: SPR-10938

spring-expression/src/main/java/org/springframework/expression/ExpressionException.java

@@ -87,6 +87,24 @@ public class ExpressionException extends RuntimeException {
 	}
 
 
+	/**
+	 * Return the exception message. Since Spring 4.0 this method returns the same
+	 * result as {@link #toDetailedString()}.
+	 * @see java.lang.Throwable#getMessage()
+	 */
+	@Override
+	public String getMessage() {
+		return toDetailedString();
+	}
+
+	/**
+	 * Return the exception simple message without including the expression that caused
+	 * the failure.
+	 */
+	public String getSimpleMessage() {
+		return super.getMessage();
+	}
+
 	public String toDetailedString() {
 		StringBuilder output = new StringBuilder();
 		if (this.expressionString!=null) {
@@ -99,7 +117,7 @@ public class ExpressionException extends RuntimeException {
 			}
 			output.append(": ");
 		}
-		output.append(getMessage());
+		output.append(getSimpleMessage());
 		return output.toString();
 	}
 

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

@@ -31,7 +31,6 @@ import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.expression.AccessException;
@@ -39,6 +38,7 @@ import org.springframework.expression.BeanResolver;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.EvaluationException;
 import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionException;
 import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.MethodExecutor;
 import org.springframework.expression.MethodResolver;
@@ -545,20 +545,26 @@ public class SpelReproTests extends ExpressionTestCase {
 		assertEquals(expectedValue,expr.getValue(TestScenarioCreator.getTestEvaluationContext()));
 	}
 
-	private void checkTemplateParsingError(String expression,String expectedMessage) throws Exception {
-		checkTemplateParsingError(expression, TemplateExpressionParsingTests.DEFAULT_TEMPLATE_PARSER_CONTEXT,expectedMessage);
+	private void checkTemplateParsingError(String expression, String expectedMessage)
+			throws Exception {
+		checkTemplateParsingError(expression, TemplateExpressionParsingTests.DEFAULT_TEMPLATE_PARSER_CONTEXT, expectedMessage);
 	}
 
-	private void checkTemplateParsingError(String expression,ParserContext context, String expectedMessage) throws Exception {
+	private void checkTemplateParsingError(String expression, ParserContext context,
+			String expectedMessage) throws Exception {
 		SpelExpressionParser parser = new SpelExpressionParser();
 		try {
 			parser.parseExpression(expression,context);
 			fail("Should have failed");
-		} catch (Exception e) {
-			if (!e.getMessage().equals(expectedMessage)) {
-				e.printStackTrace();
+		} catch (Exception ex) {
+			String message = ex.getMessage();
+			if (ex instanceof ExpressionException) {
+				message = ((ExpressionException) ex).getSimpleMessage();
+			}
+			if (!message.equals(expectedMessage)) {
+				ex.printStackTrace();
 			}
-			assertEquals(expectedMessage,e.getMessage());
+			assertThat(expectedMessage, equalTo(message));
 		}
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -193,14 +193,14 @@ public class TemplateExpressionParsingTests extends ExpressionTestCase {
 			ex = parser.parseExpression("hello ${listOfNumbersUpToTen.$[#this<5]} ${listOfNumbersUpToTen.$[#this>5] world",DEFAULT_TEMPLATE_PARSER_CONTEXT);
 			fail("Should have failed");
 		} catch (ParseException pe) {
-			assertEquals("No ending suffix '}' for expression starting at character 41: ${listOfNumbersUpToTen.$[#this>5] world",pe.getMessage());
+			assertEquals("No ending suffix '}' for expression starting at character 41: ${listOfNumbersUpToTen.$[#this>5] world", pe.getSimpleMessage());
 		}
 
 		try {
 			ex = parser.parseExpression("hello ${listOfNumbersUpToTen.$[#root.listOfNumbersUpToTen.$[#this%2==1==3]} world",DEFAULT_TEMPLATE_PARSER_CONTEXT);
 			fail("Should have failed");
 		} catch (ParseException pe) {
-			assertEquals("Found closing '}' at position 74 but most recent opening is '[' at position 30",pe.getMessage());
+			assertEquals("Found closing '}' at position 74 but most recent opening is '[' at position 30", pe.getSimpleMessage());
 		}
 	}
 
@@ -235,20 +235,20 @@ public class TemplateExpressionParsingTests extends ExpressionTestCase {
 			parser.parseExpression("hello ${'world'", DEFAULT_TEMPLATE_PARSER_CONTEXT);
 			fail("Should have failed");
 		} catch (ParseException pe) {
-			assertEquals("No ending suffix '}' for expression starting at character 6: ${'world'",pe.getMessage());
-			assertEquals("hello ${'world'",pe.getExpressionString());
+			assertEquals("No ending suffix '}' for expression starting at character 6: ${'world'", pe.getSimpleMessage());
+			assertEquals("hello ${'world'", pe.getExpressionString());
 		}
 		try {
 			parser.parseExpression("hello ${'wibble'${'world'}", DEFAULT_TEMPLATE_PARSER_CONTEXT);
 			fail("Should have failed");
 		} catch (ParseException pe) {
-			assertEquals("No ending suffix '}' for expression starting at character 6: ${'wibble'${'world'}",pe.getMessage());
+			assertEquals("No ending suffix '}' for expression starting at character 6: ${'wibble'${'world'}", pe.getSimpleMessage());
 		}
 		try {
 			parser.parseExpression("hello ${} world", DEFAULT_TEMPLATE_PARSER_CONTEXT);
 			fail("Should have failed");
 		} catch (ParseException pe) {
-			assertEquals("No expression defined within delimiter '${}' at character 6",pe.getMessage());
+			assertEquals("No expression defined within delimiter '${}' at character 6", pe.getSimpleMessage());
 		}
 	}
 

spring-expression/src/test/java/org/springframework/expression/spel/standard/SpelParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -342,16 +342,19 @@ public class SpelParserTests {
 	@Test
 	public void exceptions() {
 		ExpressionException exprEx = new ExpressionException("test");
-		assertEquals("test", exprEx.getMessage());
+		assertEquals("test", exprEx.getSimpleMessage());
 		assertEquals("test", exprEx.toDetailedString());
+		assertEquals("test", exprEx.getMessage());
 
 		exprEx = new ExpressionException("wibble", "test");
-		assertEquals("test", exprEx.getMessage());
+		assertEquals("test", exprEx.getSimpleMessage());
 		assertEquals("Expression 'wibble': test", exprEx.toDetailedString());
+		assertEquals("Expression 'wibble': test", exprEx.getMessage());
 
 		exprEx = new ExpressionException("wibble", 3, "test");
-		assertEquals("test", exprEx.getMessage());
+		assertEquals("test", exprEx.getSimpleMessage());
 		assertEquals("Expression 'wibble' @ 3: test", exprEx.toDetailedString());
+		assertEquals("Expression 'wibble' @ 3: test", exprEx.getMessage());
 	}
 
 	@Test