SPR-7173, SPR-7100

org.springframework.expression/src/main/java/org/springframework/expression/BeanResolver.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2002-2010 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.expression;
+
+/**
+ * A bean resolver can be registered with the evaluation context and will 
+ * @author Andy Clement
+ * @since 3.0.3
+ */
+public interface BeanResolver {
+
+	/**
+	 * Lookup the named bean and return it.
+	 * @param context the current evaluation context
+	 * @param beanname the name of the bean to lookup
+	 * @return a object representing the bean
+	 * @throws AccessException if there is an unexpected problem resolving the named bean
+	 */
+	Object resolve(EvaluationContext context, String beanname) throws AccessException;
+
+}
+	

org.springframework.expression/src/main/java/org/springframework/expression/EvaluationContext.java

@@ -73,6 +73,11 @@ public interface EvaluationContext {
 	 */
 	OperatorOverloader getOperatorOverloader();
 
+	/**
+	 * @return a bean resolver that can lookup named beans
+	 */
+	BeanResolver getBeanResolver();
+
 	/**
 	 * Set a named variable within this evaluation context to a specified value.
 	 * @param name variable to set

org.springframework.expression/src/main/java/org/springframework/expression/spel/SpelMessage.java

@@ -93,6 +93,9 @@ public enum SpelMessage {
 	UNABLE_TO_CREATE_LIST_FOR_INDEXING(Kind.ERROR,1054,"Unable to dynamically create a List to replace a null value"),//
 	UNABLE_TO_CREATE_MAP_FOR_INDEXING(Kind.ERROR,1055,"Unable to dynamically create a Map to replace a null value"),//
 	UNABLE_TO_DYNAMICALLY_CREATE_OBJECT(Kind.ERROR,1056,"Unable to dynamically create instance of ''{0}'' to replace a null value"),//
+	NO_BEAN_RESOLVER_REGISTERED(Kind.ERROR,1057,"No bean resolver registered in the context to resolve access to bean ''{0}''"),//
+	EXCEPTION_DURING_BEAN_RESOLUTION(Kind.ERROR, 1058, "A problem occurred when trying to resolve bean ''{0}'':''{1}''"), // 
+	INVALID_BEAN_REFERENCE(Kind.ERROR,1059,"@ can only be followed by an identifier or a quoted name"),//
 	;
 
 	private Kind kind;

org.springframework.expression/src/main/java/org/springframework/expression/spel/ast/BeanReference.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2002-2010 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.expression.spel.ast;
+
+import org.springframework.expression.AccessException;
+import org.springframework.expression.BeanResolver;
+import org.springframework.expression.EvaluationException;
+import org.springframework.expression.TypedValue;
+import org.springframework.expression.spel.ExpressionState;
+import org.springframework.expression.spel.SpelEvaluationException;
+import org.springframework.expression.spel.SpelMessage;
+
+/**
+ * Represents a bean reference to a type, for example "@foo" or "@'foo.bar'"
+ * 
+ * @author Andy Clement
+ */
+public class BeanReference extends SpelNodeImpl {
+
+	private String beanname;
+	
+	public BeanReference(int pos,String beanname) {
+		super(pos);
+		this.beanname = beanname;
+	}
+
+	@Override
+	public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
+		BeanResolver beanResolver = state.getEvaluationContext().getBeanResolver();
+		if (beanResolver==null) {
+			throw new SpelEvaluationException(getStartPosition(),SpelMessage.NO_BEAN_RESOLVER_REGISTERED, beanname);
+		}
+		try {
+		   TypedValue bean = new TypedValue(beanResolver.resolve(state.getEvaluationContext(),beanname));
+		   return bean;
+		} catch (AccessException ae) {
+			throw new SpelEvaluationException( getStartPosition(), ae, SpelMessage.EXCEPTION_DURING_BEAN_RESOLUTION,
+				beanname, ae.getMessage());
+		}
+	}
+
+	@Override
+	public String toStringAST() {
+		StringBuilder sb = new StringBuilder();
+		sb.append("@");
+		if (beanname.indexOf('.')==-1) {
+			sb.append(beanname);
+		} else {
+			sb.append("'").append(beanname).append("'");
+		}
+		return sb.toString();
+	}
+	
+}

org.springframework.expression/src/main/java/org/springframework/expression/spel/standard/InternalSpelExpressionParser.java

@@ -28,6 +28,7 @@ import org.springframework.expression.spel.SpelMessage;
 import org.springframework.expression.spel.SpelParseException;
 import org.springframework.expression.spel.SpelParserConfiguration;
 import org.springframework.expression.spel.ast.Assign;
+import org.springframework.expression.spel.ast.BeanReference;
 import org.springframework.expression.spel.ast.BooleanLiteral;
 import org.springframework.expression.spel.ast.CompoundExpression;
 import org.springframework.expression.spel.ast.ConstructorReference;
@@ -437,6 +438,8 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 			return pop();
 		} else if (maybeEatTypeReference() || maybeEatNullReference() || maybeEatConstructorReference() || maybeEatMethodOrProperty(false) || maybeEatFunctionOrVar()) {
 			return pop();
+		} else if (maybeEatBeanReference()) {
+			return pop();
 		} else if (maybeEatProjection(false) || maybeEatSelection(false) || maybeEatIndexer()) {
 			return pop();
 		} else {
@@ -444,7 +447,30 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 		}
 	}
 	
+	// parse: @beanname @'bean.name'
+	// quoted if dotted
+	private boolean maybeEatBeanReference() {
+		if (peekToken(TokenKind.BEAN_REF)) {
+			Token beanRefToken = nextToken();
+			Token beanNameToken = null;
+			String beanname = null;
+			if (peekToken(TokenKind.IDENTIFIER)) {
+				beanNameToken = eatToken(TokenKind.IDENTIFIER);
+				beanname = beanNameToken.data;
+			} else if (peekToken(TokenKind.LITERAL_STRING)) {
+				beanNameToken = eatToken(TokenKind.LITERAL_STRING);
+				beanname = beanNameToken.stringValue();
+				beanname = beanname.substring(1, beanname.length() - 1);
+			} else {
+				raiseInternalException(beanRefToken.startpos,SpelMessage.INVALID_BEAN_REFERENCE);
+			}
 			
+			BeanReference beanReference = new BeanReference(toPos(beanNameToken),beanname);
+			constructedNodes.push(beanReference);
+			return true;
+		}
+		return false;
+	}
 
 	private boolean maybeEatTypeReference() {
 		if (peekToken(TokenKind.IDENTIFIER)) {
@@ -454,7 +480,7 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 			}
 			nextToken();
 			eatToken(TokenKind.LPAREN);
-			SpelNodeImpl node = eatPossiblyQualifiedId(true);
+			SpelNodeImpl node = eatPossiblyQualifiedId();
 			// dotted qualified id
 			eatToken(TokenKind.RPAREN);
 			constructedNodes.push(new TypeReference(toPos(typeName),node));
@@ -518,29 +544,22 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 	}
 
 	/**
-	 * Eat an identifier, possibly qualified (meaning that it is dotted).  If the dollarAllowed parameter is true then
-	 * it will process any dollar characters found between names, and this allows it to support inner type references
-	 * correctly.  For example 'com.foo.bar.Outer$Inner' will produce the identifier sequence com, foo, bar, Outer, $Inner,
-	 * note that the $ has been prefixed onto the Inner identifier.  The code in TypeReference which reforms this into
-	 * a typename copes with the $ prefixed identifiers.
+	 * Eat an identifier, possibly qualified (meaning that it is dotted).
 	 * TODO AndyC Could create complete identifiers (a.b.c) here rather than a sequence of them? (a, b, c)
 	 */
-	private SpelNodeImpl eatPossiblyQualifiedId(boolean dollarAllowed) {
+	private SpelNodeImpl eatPossiblyQualifiedId() {
 		List<SpelNodeImpl> qualifiedIdPieces = new ArrayList<SpelNodeImpl>();
 		Token startnode = eatToken(TokenKind.IDENTIFIER);
 		qualifiedIdPieces.add(new Identifier(startnode.stringValue(),toPos(startnode)));
-		boolean dollar = false;
-		while (peekToken(TokenKind.DOT,true) || (dollarAllowed && (dollar = peekToken(TokenKind.DOLLAR,true)))) {
+		while (peekToken(TokenKind.DOT,true)) {
 			Token node = eatToken(TokenKind.IDENTIFIER);
-			if (dollar) {
-				qualifiedIdPieces.add(new Identifier("$"+node.stringValue(),((node.startpos-1)<<16)+node.endpos));			
-			} else {
 			qualifiedIdPieces.add(new Identifier(node.stringValue(),toPos(node)));							
 		}
-		}
 		return new QualifiedIdentifier(toPos(startnode.startpos,qualifiedIdPieces.get(qualifiedIdPieces.size()-1).getEndPosition()),qualifiedIdPieces.toArray(new SpelNodeImpl[qualifiedIdPieces.size()]));
 	}
 	
+	// This is complicated due to the support for dollars in identifiers.  Dollars are normally separate tokens but
+	// there we want to combine a series of identifiers and dollars into a single identifier
 	private boolean maybeEatMethodOrProperty(boolean nullSafeNavigation) {
 			if (peekToken(TokenKind.IDENTIFIER)) {
 			Token methodOrPropertyName = nextToken();
@@ -557,6 +576,7 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 			}
 		}
 		return false;
+
 	}
 	
 	//constructor  
@@ -564,7 +584,7 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 	private boolean maybeEatConstructorReference() {
 		if (peekIdentifierToken("new")) {
 			Token newToken = nextToken();
-			SpelNodeImpl possiblyQualifiedConstructorName = eatPossiblyQualifiedId(true);
+			SpelNodeImpl possiblyQualifiedConstructorName = eatPossiblyQualifiedId();
 			List<SpelNodeImpl> nodes = new ArrayList<SpelNodeImpl>();
 			nodes.add(possiblyQualifiedConstructorName);
 			eatConstructorArgs(nodes);

org.springframework.expression/src/main/java/org/springframework/expression/spel/standard/TokenKind.java

@@ -26,8 +26,8 @@ enum TokenKind {
 	COLON(":"),HASH("#"),RSQUARE("]"), LSQUARE("["), 
 	DOT("."), PLUS("+"), STAR("*"), DIV("/"), NOT("!"), MINUS("-"), SELECT_FIRST("^["), SELECT_LAST("$["), QMARK("?"), PROJECT("!["),
 	GE(">="),GT(">"),LE("<="),LT("<"),EQ("=="),NE("!="),ASSIGN("="), INSTANCEOF("instanceof"), MATCHES("matches"), BETWEEN("between"),
-	SELECT("?["),  MOD("%"), POWER("^"), DOLLAR("$"),
-	ELVIS("?:"), SAFE_NAVI("?.");
+	SELECT("?["),  MOD("%"), POWER("^"),
+	ELVIS("?:"), SAFE_NAVI("?."), BEAN_REF("@")
 	;
 	 
 	char[] tokenChars;

org.springframework.expression/src/main/java/org/springframework/expression/spel/standard/Tokenizer.java

@@ -96,6 +96,9 @@ class Tokenizer {
 				case ']':
 					pushCharToken(TokenKind.RSQUARE);
 					break;
+				case '@':
+					pushCharToken(TokenKind.BEAN_REF);
+					break;
 				case '^':
 					if (isTwoCharToken(TokenKind.SELECT_FIRST)) {
 						pushPairToken(TokenKind.SELECT_FIRST);
@@ -134,7 +137,7 @@ class Tokenizer {
 					if (isTwoCharToken(TokenKind.SELECT_LAST)) {
 						pushPairToken(TokenKind.SELECT_LAST);
 					} else {
-						pushCharToken(TokenKind.DOLLAR);					
+						lexIdentifier();
 					}
 					break;
 				case '>':
@@ -424,9 +427,9 @@ class Tokenizer {
 		tokens.add(new Token(kind,pos,pos+kind.getLength()));
 	}
 
-	//	ID:	('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'_'|'0'..'9'|DOT_ESCAPED)*;
+	//	ID:	('a'..'z'|'A'..'Z'|'_'|'$') ('a'..'z'|'A'..'Z'|'_'|'$'|'0'..'9'|DOT_ESCAPED)*;
 	private boolean isIdentifier(char ch) {
-		return isAlphabetic(ch) || isDigit(ch) || ch=='_';
+		return isAlphabetic(ch) || isDigit(ch) || ch=='_' || ch=='$';
 	}
 	
 	private boolean isChar(char a,char b) {

org.springframework.expression/src/main/java/org/springframework/expression/spel/support/StandardEvaluationContext.java

@@ -23,6 +23,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.expression.BeanResolver;
 import org.springframework.expression.ConstructorResolver;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.MethodFilter;
@@ -66,6 +67,8 @@ public class StandardEvaluationContext implements EvaluationContext {
 
 	private final Map<String, Object> variables = new HashMap<String, Object>();
 	
+	private BeanResolver beanResolver;
+
 
 	public StandardEvaluationContext() {
 		setRootObject(null);
@@ -134,6 +137,14 @@ public class StandardEvaluationContext implements EvaluationContext {
 		return this.methodResolvers;
 	}
 
+	public void setBeanResolver(BeanResolver beanResolver) {
+		this.beanResolver = beanResolver;
+	}
+	
+	public BeanResolver getBeanResolver() {
+		return this.beanResolver;
+	}
+	
 	public void setMethodResolvers(List<MethodResolver> methodResolvers) {
 		this.methodResolvers = methodResolvers;
 	}

org.springframework.expression/src/test/java/org/springframework/expression/spel/ParsingTests.java

@@ -20,8 +20,8 @@ import junit.framework.Assert;
 
 import org.junit.Test;
 import org.springframework.expression.ParseException;
-import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
 
 /**
  * Parse some expressions and check we get the AST we expect. Rather than inspecting each node in the AST, we ask it to
@@ -267,18 +267,18 @@ public class ParsingTests {
 	// parseCheck("{'a','b','a','d','e'}.distinct()");
 	// }
 
-	// // references
-	// public void testReferences01() {
-	// parseCheck("@(foo)");
-	// }
-	//
-	// public void testReferences02() {
-	// parseCheck("@(p:foo)");
-	// }
-	//
-	// public void testReferences04() {
-	// parseCheck("@(a/b/c:foo)", "@(a.b.c:foo)");
-	// }// normalized to '.' for separator in QualifiedIdentifier
+	// references
+	@Test
+	public void testReferences01() {
+		parseCheck("@foo");
+		parseCheck("@'foo.bar'");
+		parseCheck("@\"foo.bar.goo\"","@'foo.bar.goo'");
+	}
+
+	@Test
+	public void testReferences03() {
+		parseCheck("@$$foo");
+	}
 
 	// properties
 	@Test

org.springframework.expression/src/test/java/org/springframework/expression/spel/SpringEL300Tests.java

@@ -24,6 +24,7 @@ import junit.framework.Assert;
 
 import org.junit.Test;
 import org.springframework.expression.AccessException;
+import org.springframework.expression.BeanResolver;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.EvaluationException;
 import org.springframework.expression.Expression;
@@ -350,6 +351,47 @@ public class SpringEL300Tests extends ExpressionTestCase {
 		Assert.assertEquals("hello",name);
 	}
 	
+	/** $ related identifiers */
+	@SuppressWarnings("unchecked")
+	@Test
+	public void testDollarPrefixedIdentifier_SPR7100() {
+		Holder h = new Holder();
+		StandardEvaluationContext eContext = new StandardEvaluationContext(h);
+		eContext.addPropertyAccessor(new MapAccessor());
+		h.map.put("$foo","wibble");
+		h.map.put("foo$bar","wobble");
+		h.map.put("foobar$$","wabble");
+		h.map.put("$","wubble");
+		h.map.put("$$","webble");
+		h.map.put("$_$","tribble");
+		String name = null;
+		Expression expr = null;
+		
+		expr = new SpelExpressionParser().parseRaw("map.$foo");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("wibble",name);
+
+		expr = new SpelExpressionParser().parseRaw("map.foo$bar");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("wobble",name);
+
+		expr = new SpelExpressionParser().parseRaw("map.foobar$$");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("wabble",name);
+
+		expr = new SpelExpressionParser().parseRaw("map.$");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("wubble",name);
+
+		expr = new SpelExpressionParser().parseRaw("map.$$");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("webble",name);
+
+		expr = new SpelExpressionParser().parseRaw("map.$_$");
+		name = expr.getValue(eContext,String.class);
+		Assert.assertEquals("tribble",name);
+	}
+
 	/** Should be accessing Goo.wibble field because 'bar' variable evaluates to "wibble" */
 	@Test
 	public void testIndexingAsAPropertyAccess_SPR6968_3() {
@@ -393,6 +435,36 @@ public class SpringEL300Tests extends ExpressionTestCase {
 		Assert.assertEquals("world",g.value);
 	}
 	
+	@Test
+	public void testDollars() {
+		StandardEvaluationContext eContext = new StandardEvaluationContext(new XX());
+		Expression expr = null;
+		expr = new SpelExpressionParser().parseRaw("m['$foo']");
+		eContext.setVariable("file_name","$foo");
+		Assert.assertEquals("wibble",expr.getValue(eContext,String.class));
+	}
+	
+	@Test
+	public void testDollars2() {
+		StandardEvaluationContext eContext = new StandardEvaluationContext(new XX());
+		Expression expr = null;
+		expr = new SpelExpressionParser().parseRaw("m[$foo]");
+		eContext.setVariable("file_name","$foo");
+		Assert.assertEquals("wibble",expr.getValue(eContext,String.class));
+	}
+	
+	static class XX {
+		public Map<String,String> m;
+		
+		public String floo ="bar";
+		
+		public XX() {
+			 m = new HashMap<String,String>();
+			m.put("$foo","wibble");
+			m.put("bar","siddle");
+		}
+	}
+
 	static class Goo {
 		
 		public static Goo instance = new Goo();
@@ -411,6 +483,11 @@ public class SpringEL300Tests extends ExpressionTestCase {
 		
 	}
 	
+	static class Holder {
+		
+		public Map map = new HashMap();
+	}
+	
 	// ---
 
 	private void checkTemplateParsing(String expression, String expectedValue) throws Exception {
@@ -452,5 +529,102 @@ public class SpringEL300Tests extends ExpressionTestCase {
 		}
 	};
 	
+//	@Test
+//	public void testFails() {
+//		
+//		StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
+//		evaluationContext.setVariable("target", new Foo2());
+//		for (int i = 0; i < 300000; i++) {
+//			evaluationContext.addPropertyAccessor(new MapAccessor());
+//			ExpressionParser parser = new SpelExpressionParser();
+//			Expression expression = parser.parseExpression("#target.execute(payload)");
+//			Message message = new Message();
+//			message.setPayload(i+"");
+//			expression.getValue(evaluationContext, message);
+//		}	
+//	}
+	
+	static class Foo2 {
+		public void execute(String str){
+			System.out.println("Value: " + str);
+		}
+	}
+	
+	static class Message{
+		private String payload;
+
+		public String getPayload() {
+			return payload;
+		}
+
+		public void setPayload(String payload) {
+			this.payload = payload;
+		}
+	}
+
+	// bean resolver tests
+	
+	@Test
+	public void beanResolution() {
+		StandardEvaluationContext eContext = new StandardEvaluationContext(new XX());
+		Expression expr = null;
+
+		// no resolver registered == exception
+		try {
+			expr = new SpelExpressionParser().parseRaw("@foo");
+			Assert.assertEquals("custard",expr.getValue(eContext,String.class));
+		} catch (SpelEvaluationException see) {
+			Assert.assertEquals(SpelMessage.NO_BEAN_RESOLVER_REGISTERED,see.getMessageCode());
+			Assert.assertEquals("foo",see.getInserts()[0]);
+		}
+		
+		eContext.setBeanResolver(new MyBeanResolver());
+
+		// bean exists
+		expr = new SpelExpressionParser().parseRaw("@foo");
+		Assert.assertEquals("custard",expr.getValue(eContext,String.class));
+
+		// bean does not exist
+		expr = new SpelExpressionParser().parseRaw("@bar");
+		Assert.assertEquals(null,expr.getValue(eContext,String.class));
+
+		// bean name will cause AccessException
+		expr = new SpelExpressionParser().parseRaw("@goo");
+		try {
+			Assert.assertEquals(null,expr.getValue(eContext,String.class));
+		} catch (SpelEvaluationException see) {
+			Assert.assertEquals(SpelMessage.EXCEPTION_DURING_BEAN_RESOLUTION,see.getMessageCode());
+			Assert.assertEquals("goo",see.getInserts()[0]);
+			Assert.assertTrue(see.getCause() instanceof AccessException);
+			Assert.assertTrue(((AccessException)see.getCause()).getMessage().startsWith("DONT"));
+		}
+		
+		// bean exists
+		expr = new SpelExpressionParser().parseRaw("@'foo.bar'");
+		Assert.assertEquals("trouble",expr.getValue(eContext,String.class));
+		
+		// bean exists
+		try {
+			expr = new SpelExpressionParser().parseRaw("@378");
+			Assert.assertEquals("trouble",expr.getValue(eContext,String.class));
+		} catch (SpelParseException spe) {
+			Assert.assertEquals(SpelMessage.INVALID_BEAN_REFERENCE,spe.getMessageCode());
+		}
+	}
+	
+	static class MyBeanResolver implements BeanResolver {
+		public Object resolve(EvaluationContext context, String beanname) throws AccessException {
+			if (beanname.equals("foo")) {
+				return "custard";
+			} else if (beanname.equals("foo.bar")) {
+				return "trouble";
+			} else if (beanname.equals("goo")) {
+				throw new AccessException("DONT ASK ME ABOUT GOO");
+			}
+			return null;
+		}
+	}
+	
+	// end bean resolver tests
 
 }