revised EvalTag implementation

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@2992 50f2f4bb-b051-0410-bef5-90022cba6387

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/AnnotationDrivenBeanDefinitionParser.java

@@ -38,7 +38,7 @@ import org.springframework.util.ClassUtils;
 import org.springframework.validation.Validator;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.bind.support.ConfigurableWebBindingInitializer;
-import org.springframework.web.servlet.handler.ConversionServiceHandlerInterceptor;
+import org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor;
 import org.springframework.web.servlet.handler.MappedInterceptor;
 import org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter;
 import org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping;
@@ -112,7 +112,7 @@ class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {
 		annAdapterDef.getPropertyValues().add("messageConverters", getMessageConverters(source));
 		String annAdapterName = parserContext.getReaderContext().registerWithGeneratedName(annAdapterDef);
 
-		RootBeanDefinition csInterceptorDef = new RootBeanDefinition(ConversionServiceHandlerInterceptor.class);
+		RootBeanDefinition csInterceptorDef = new RootBeanDefinition(ConversionServiceExposingInterceptor.class);
 		csInterceptorDef.setSource(source);
 		csInterceptorDef.getConstructorArgumentValues().addIndexedArgumentValue(0, conversionService);		
 		RootBeanDefinition mappedCsInterceptorDef = new RootBeanDefinition(MappedInterceptor.class);

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/ConversionServiceExposingInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * 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.
@@ -17,7 +17,6 @@
 package org.springframework.web.servlet.handler;
 
 import java.io.IOException;
-
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -26,28 +25,35 @@ import org.springframework.core.convert.ConversionService;
 import org.springframework.util.Assert;
 
 /**
- * Interceptor that places the configured {@link ConversionService} in request scope so it's available during request processing.
- * Mainly for use within JSP tags such as the spring:eval tag.
- * The request attribute name is "org.springframework.core.convert.ConversionService", the value of ConversionService.class.getName();
+ * Interceptor that places the configured {@link ConversionService} in request scope
+ * so it's available during request processing. The request attribute name is
+ * "org.springframework.core.convert.ConversionService", the value of
+ * <code>ConversionService.class.getName()</code>.
+ *
+ * <p>Mainly for use within JSP tags such as the spring:eval tag.
+ *
  * @author Keith Donald
  * @since 3.0.1
  */
-public class ConversionServiceHandlerInterceptor extends HandlerInterceptorAdapter {
+public class ConversionServiceExposingInterceptor extends HandlerInterceptorAdapter {
 	
 	private final ConversionService conversionService;
 
+
 	/**
-	 * Creates a new {@link ConversionServiceHandlerInterceptor}.
-	 * @param conversionService the conversion service to export to request scope when this interceptor is invoked.
+	 * Creates a new {@link ConversionServiceExposingInterceptor}.
+	 * @param conversionService the conversion service to export to request scope when this interceptor is invoked
 	 */
-	public ConversionServiceHandlerInterceptor(ConversionService conversionService) {
+	public ConversionServiceExposingInterceptor(ConversionService conversionService) {
 		Assert.notNull(conversionService, "The ConversionService may not be null");
 		this.conversionService = conversionService;
 	}
 
+
 	@Override
-	public final boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
+	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
 			throws ServletException, IOException {
+
 		request.setAttribute(ConversionService.class.getName(), this.conversionService);
 		return true;
 	}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/tags/EvalTag.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * 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.
@@ -17,12 +17,9 @@
 package org.springframework.web.servlet.tags;
 
 import java.io.IOException;
-
 import javax.servlet.jsp.JspException;
 import javax.servlet.jsp.PageContext;
-import javax.servlet.jsp.el.ELException;
 
-import org.springframework.beans.BeansException;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.expression.AccessException;
 import org.springframework.expression.EvaluationContext;
@@ -41,15 +38,17 @@ import org.springframework.web.util.TagUtils;
 /**
  * JSP tag for evaluating expressions with the Spring Expression Language (SpEL).
  * Supports the standard JSP evaluation context consisting of implicit variables and scoped attributes.
- * 
+ *
  * @author Keith Donald
  * @since 3.0.1
  */
 public class EvalTag extends HtmlEscapingAwareTag {
 
-	private ExpressionParser expressionParser;
-	
-	private String expression;
+	private final ExpressionParser expressionParser = new SpelExpressionParser();
+
+	private EvaluationContext evaluationContext;
+
+	private Expression expression;
 
 	private String var;
 
@@ -57,11 +56,18 @@ public class EvalTag extends HtmlEscapingAwareTag {
 
 	private boolean javaScriptEscape = false;
 
+
+	@Override
+	public void setPageContext(PageContext pageContext) {
+		super.setPageContext(pageContext);
+		this.evaluationContext = createEvaluationContext(pageContext);
+	}
+
 	/**
 	 * Set the expression to evaluate.
 	 */
 	public void setExpression(String expression) {
-		this.expression = expression;
+		this.expression = this.expressionParser.parseExpression(expression);
 	}
 
 	/**
@@ -89,55 +95,51 @@ public class EvalTag extends HtmlEscapingAwareTag {
 				ExpressionEvaluationUtils.evaluateBoolean("javaScriptEscape", javaScriptEscape, this.pageContext);
 	}
 
+
 	@Override
 	public int doStartTagInternal() throws JspException {
-		this.expressionParser = new SpelExpressionParser();
 		return EVAL_BODY_INCLUDE;
 	}
 
 	@Override
 	public int doEndTag() throws JspException {
-		Expression expression = this.expressionParser.parseExpression(this.expression);
-		EvaluationContext context = createEvaluationContext();
 		if (this.var == null) {
 			try {
-				String result = expression.getValue(context, String.class);
+				String result = this.expression.getValue(this.evaluationContext, String.class);
 				result = isHtmlEscape() ? HtmlUtils.htmlEscape(result) : result;
 				result = this.javaScriptEscape ? JavaScriptUtils.javaScriptEscape(result) : result;
 				pageContext.getOut().print(result);
 			}
-			catch (IOException e) {
-				throw new JspException(e);
+			catch (IOException ex) {
+				throw new JspException(ex);
 			}
 		}
 		else {
-			Object result = expression.getValue(context);
-			pageContext.setAttribute(var, result, scope);
+			Object result = this.expression.getValue(this.evaluationContext);
+			pageContext.setAttribute(this.var, result, this.scope);
 		}
 		return EVAL_PAGE;
 	}
-	
-	private EvaluationContext createEvaluationContext() {
+
+
+	private EvaluationContext createEvaluationContext(PageContext pageContext) {
 		StandardEvaluationContext context = new StandardEvaluationContext();
-		context.addPropertyAccessor(new JspPropertyAccessor(this.pageContext));
-		ConversionService conversionService = getConversionService();
+		context.addPropertyAccessor(new JspPropertyAccessor(pageContext));
+		ConversionService conversionService = getConversionService(pageContext);
 		if (conversionService != null) {
 			context.setTypeConverter(new StandardTypeConverter(conversionService));
 		}
 		return context;
 	}
 	
-	private ConversionService getConversionService() {
-		try {
-			return (ConversionService) this.pageContext.getRequest().getAttribute(ConversionService.class.getName());
-		} catch (BeansException e) {
-			return null;
-		}
+	private ConversionService getConversionService(PageContext pageContext) {
+		return (ConversionService) pageContext.getRequest().getAttribute(ConversionService.class.getName());
 	}
-	
+
+
 	private static class JspPropertyAccessor implements PropertyAccessor {
 
-		private PageContext pageContext;
+		private final PageContext pageContext;
 		
 		public JspPropertyAccessor(PageContext pageContext) {
 			this.pageContext = pageContext;
@@ -147,17 +149,11 @@ public class EvalTag extends HtmlEscapingAwareTag {
 			return null;
 		}
 
-		public boolean canRead(EvaluationContext context, Object target,
-				String name) throws AccessException {
-			Object implicitVar = resolveImplicitVariable(name);
-			if (implicitVar != null) {
-				return true;
-			}
-			return this.pageContext.findAttribute(name) != null;
+		public boolean canRead(EvaluationContext context, Object target, String name) throws AccessException {
+			return (resolveImplicitVariable(name) != null || this.pageContext.findAttribute(name) != null);
 		}
 
-		public TypedValue read(EvaluationContext context, Object target,
-				String name) throws AccessException {
+		public TypedValue read(EvaluationContext context, Object target, String name) throws AccessException {
 			Object implicitVar = resolveImplicitVariable(name);
 			if (implicitVar != null) {
 				return new TypedValue(implicitVar);
@@ -165,24 +161,23 @@ public class EvalTag extends HtmlEscapingAwareTag {
 			return new TypedValue(this.pageContext.findAttribute(name));
 		}
 
-		public boolean canWrite(EvaluationContext context, Object target,
-				String name) throws AccessException {
+		public boolean canWrite(EvaluationContext context, Object target, String name) {
 			return false;
 		}
 
-		public void write(EvaluationContext context, Object target,
-				String name, Object newValue) throws AccessException {
+		public void write(EvaluationContext context, Object target, String name, Object newValue) {
 			throw new UnsupportedOperationException();
 		}
 		
 		private Object resolveImplicitVariable(String name) throws AccessException {
 			try {
 				return this.pageContext.getVariableResolver().resolveVariable(name);
-			} catch (ELException e) {
-				throw new AccessException("Unexpected exception occurred accessing '" + name + "' as an implicit variable", e);
+			}
+			catch (Exception ex) {
+				throw new AccessException(
+						"Unexpected exception occurred accessing '" + name + "' as an implicit variable", ex);
 			}
 		}
-		
 	}
 
-}
+}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/tags/RequestContextAwareTag.java

@@ -1,12 +1,12 @@
 /*
- * Copyright 2002-2006 the original author or authors.
- * 
+ * 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.
@@ -47,9 +47,10 @@ import org.springframework.web.servlet.support.RequestContext;
  */
 public abstract class RequestContextAwareTag extends TagSupport implements TryCatchFinally {
 
-	/** {@link javax.servlet.jsp.PageContext} attribute for page-level
+	/**
+	 * {@link javax.servlet.jsp.PageContext} attribute for page-level
 	 * {@link RequestContext} instance.
-	 * */
+	 */
 	public static final String REQUEST_CONTEXT_PAGE_ATTRIBUTE =
 			"org.springframework.web.servlet.tags.REQUEST_CONTEXT";
 

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/config/MvcNamespaceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * 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.
@@ -53,7 +53,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.context.support.GenericWebApplicationContext;
 import org.springframework.web.servlet.HandlerExecutionChain;
 import org.springframework.web.servlet.ModelAndView;
-import org.springframework.web.servlet.handler.ConversionServiceHandlerInterceptor;
+import org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor;
 import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.handler.WebRequestHandlerInterceptorAdapter;
 import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
@@ -115,8 +115,8 @@ public class MvcNamespaceTests {
 
 		HandlerExecutionChain chain = mapping.getHandler(request);
 		assertEquals(2, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
-		ConversionServiceHandlerInterceptor interceptor = (ConversionServiceHandlerInterceptor) chain.getInterceptors()[1];
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
+		ConversionServiceExposingInterceptor interceptor = (ConversionServiceExposingInterceptor) chain.getInterceptors()[1];
 		interceptor.preHandle(request, response, handler);
 		assertSame(appContext.getBean(ConversionService.class), request.getAttribute(ConversionService.class.getName()));
 		
@@ -144,8 +144,8 @@ public class MvcNamespaceTests {
 
 		HandlerExecutionChain chain = mapping.getHandler(request);
 		assertEquals(2, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
-		ConversionServiceHandlerInterceptor interceptor = (ConversionServiceHandlerInterceptor) chain.getInterceptors()[1];
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
+		ConversionServiceExposingInterceptor interceptor = (ConversionServiceExposingInterceptor) chain.getInterceptors()[1];
 		interceptor.preHandle(request, response, handler);
 		assertSame(appContext.getBean("conversionService"), request.getAttribute(ConversionService.class.getName()));
 	
@@ -194,7 +194,7 @@ public class MvcNamespaceTests {
 
 		HandlerExecutionChain chain = mapping.getHandler(request);
 		assertEquals(4, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
 		assertTrue(chain.getInterceptors()[2] instanceof LocaleChangeInterceptor);
 		assertTrue(chain.getInterceptors()[3] instanceof ThemeChangeInterceptor);
 
@@ -225,7 +225,7 @@ public class MvcNamespaceTests {
 
 		HandlerExecutionChain chain = mapping.getHandler(request);
 		assertEquals(4, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);		
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
 		assertTrue(chain.getInterceptors()[2] instanceof LocaleChangeInterceptor);
 		assertTrue(chain.getInterceptors()[3] instanceof ThemeChangeInterceptor);	
 		LocaleChangeInterceptor interceptor = (LocaleChangeInterceptor) chain.getInterceptors()[2];
@@ -249,7 +249,7 @@ public class MvcNamespaceTests {
 
 		HandlerExecutionChain chain = mapping.getHandler(request);
 		assertEquals(4, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
 		assertTrue(chain.getInterceptors()[2] instanceof LocaleChangeInterceptor);
 		assertTrue(chain.getInterceptors()[3] instanceof ThemeChangeInterceptor);
 
@@ -263,7 +263,7 @@ public class MvcNamespaceTests {
 		request.setMethod("GET");
 		chain = mapping2.getHandler(request);
 		assertEquals(4, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
 		assertTrue(chain.getInterceptors()[2] instanceof LocaleChangeInterceptor);
 		assertTrue(chain.getInterceptors()[3] instanceof ThemeChangeInterceptor);
 		ModelAndView mv = adapter.handle(request, new MockHttpServletResponse(), chain.getHandler());
@@ -272,7 +272,7 @@ public class MvcNamespaceTests {
 		request.setRequestURI("/bar");
 		chain = mapping2.getHandler(request);
 		assertEquals(4, chain.getInterceptors().length);
-		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceHandlerInterceptor);
+		assertTrue(chain.getInterceptors()[1] instanceof ConversionServiceExposingInterceptor);
 		assertTrue(chain.getInterceptors()[2] instanceof LocaleChangeInterceptor);
 		assertTrue(chain.getInterceptors()[3] instanceof ThemeChangeInterceptor);
 		ModelAndView mv2 = adapter.handle(request, new MockHttpServletResponse(), chain.getHandler());

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/tags/EvalTagTests.java

@@ -1,12 +1,12 @@
 /*
- * Copyright 2008 the original author or authors.
- * 
+ * 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.