INT-3209 DefaultFileNameGenerator - SpEL Parsing

JIRA: https://jira.springsource.org/browse/INT-3209

Previously, the DefaultFileNameGenerator re-parsed the
SpEL expression for every message.

Compile the SpEL once (and if it is changed).

Change unit tests to match changes.

spring-integration-file/src/main/java/org/springframework/integration/file/DefaultFileNameGenerator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 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.
@@ -18,6 +18,9 @@ package org.springframework.integration.file;
 
 import java.io.File;
 
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.integration.Message;
 import org.springframework.integration.util.AbstractExpressionEvaluator;
 import org.springframework.util.Assert;
@@ -34,13 +37,17 @@ import org.springframework.util.StringUtils;
  * associated with the header if no expression has been provided), it checks if
  * the Message payload is a File instance, and if so, it uses the same name.
  * Finally, it falls back to the Message ID and adds the suffix '.msg'.
- * 
+ *
  * @author Mark Fisher
+ * @author Gary Russell
  */
 public class DefaultFileNameGenerator extends AbstractExpressionEvaluator implements FileNameGenerator {
 
-	private volatile String expression = "headers['" + FileHeaders.FILENAME + "']";
+	private static final String DEFAULT_EXPRESSION = "headers['" + FileHeaders.FILENAME + "']";
 
+	private final static ExpressionParser parser = new SpelExpressionParser();
+
+	private volatile Expression expression = parser.parseExpression(DEFAULT_EXPRESSION);
 
 	/**
 	 * Specify an expression to be evaluated against the Message
@@ -48,7 +55,7 @@ public class DefaultFileNameGenerator extends AbstractExpressionEvaluator implem
 	 */
 	public void setExpression(String expression) {
 		Assert.hasText(expression, "expression must not be empty");
-		this.expression = expression;
+		this.expression = parser.parseExpression(expression);
 	}
 
 	/**
@@ -57,9 +64,10 @@ public class DefaultFileNameGenerator extends AbstractExpressionEvaluator implem
 	 */
 	public void setHeaderName(String headerName) {
 		Assert.notNull(headerName, "'headerName' must not be null");
-		this.expression = "headers['" + headerName + "']";
+		this.expression = parser.parseExpression("headers['" + headerName + "']");
 	}
 
+	@Override
 	public String generateFileName(Message<?> message) {
 		Object filenameProperty = this.evaluateExpression(this.expression, message);
 		if (filenameProperty instanceof String && StringUtils.hasText((String) filenameProperty)) {

spring-integration-file/src/test/java/org/springframework/integration/file/DefaultFileNameGeneratorTests.java

@@ -122,6 +122,17 @@ public class DefaultFileNameGeneratorTests {
 		assertEquals("bar", filename);
 	}
 
+	@Test
+	public void customExpressionTakesPrecedenceOverFilePayload() {
+		DefaultFileNameGenerator generator = new DefaultFileNameGenerator();
+		generator.setBeanFactory(mock(BeanFactory.class));
+		generator.setExpression("'foobar'");
+		File payload = new File("/some/path/ignore");
+		Message<?> message = MessageBuilder.withPayload(payload).build();
+		String filename = generator.generateFileName(message);
+		assertEquals("foobar", filename);
+	}
+
 	@Test
 	public void customHeaderNameTakesPrecedenceOverDefault() {
 		DefaultFileNameGenerator generator = new DefaultFileNameGenerator();

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileOutboundChannelAdapterParserTests.java

@@ -106,9 +106,9 @@ public class FileOutboundChannelAdapterParserTests {
 		assertThat(actual, is(expected));
 		DefaultFileNameGenerator fileNameGenerator = (DefaultFileNameGenerator) handlerAccessor.getPropertyValue("fileNameGenerator");
 		assertNotNull(fileNameGenerator);
-		String expression = (String) TestUtils.getPropertyValue(fileNameGenerator, "expression");
+		Expression expression = TestUtils.getPropertyValue(fileNameGenerator, "expression", Expression.class);
 		assertNotNull(expression);
-		assertEquals("'foo.txt'", expression);
+		assertEquals("'foo.txt'", expression.getExpressionString());
 		assertEquals(Boolean.FALSE, handlerAccessor.getPropertyValue("deleteSourceFiles"));
 	}
 

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileOutboundGatewayParserTests.java

@@ -26,6 +26,7 @@ import java.io.File;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -93,9 +94,9 @@ public class FileOutboundGatewayParserTests {
 		assertEquals(Boolean.TRUE, handlerAccessor.getPropertyValue("requiresReply"));
 		DefaultFileNameGenerator fileNameGenerator = (DefaultFileNameGenerator) handlerAccessor.getPropertyValue("fileNameGenerator");
 		assertNotNull(fileNameGenerator);
-		String expression = (String) TestUtils.getPropertyValue(fileNameGenerator, "expression");
+		Expression expression = TestUtils.getPropertyValue(fileNameGenerator, "expression", Expression.class);
 		assertNotNull(expression);
-		assertEquals("'foo.txt'", expression);
+		assertEquals("'foo.txt'", expression.getExpressionString());
 
 		Long sendTimeout = TestUtils.getPropertyValue(handler, "messagingTemplate.sendTimeout", Long.class);
 		assertEquals(Long.valueOf(777), sendTimeout);

spring-integration-sftp/src/test/java/org/springframework/integration/sftp/config/OutboundChannelAdapterParserTests.java

@@ -108,8 +108,9 @@ public class OutboundChannelAdapterParserTests {
 		assertNotNull(remoteDirectoryExpression);
 		assertEquals("'foo' + '/' + 'bar'", remoteDirectoryExpression.getExpressionString());
 		FileNameGenerator generator = (FileNameGenerator) TestUtils.getPropertyValue(handler, "remoteFileTemplate.fileNameGenerator");
-		String fileNameGeneratorExpression = (String) TestUtils.getPropertyValue(generator, "expression");
-		assertEquals("payload.getName() + '-foo'", fileNameGeneratorExpression);
+		Expression fileNameGeneratorExpression = TestUtils.getPropertyValue(generator, "expression", Expression.class);
+		assertNotNull(fileNameGeneratorExpression);
+		assertEquals("payload.getName() + '-foo'", fileNameGeneratorExpression.getExpressionString());
 		assertEquals("UTF-8", TestUtils.getPropertyValue(handler, "remoteFileTemplate.charset"));
 		assertNull(TestUtils.getPropertyValue(handler, "remoteFileTemplate.temporaryDirectoryExpressionProcessor"));