Context namespace exposes value-separator attribute for property-placeholder element

Issue: SPR-7794

Author: jhoeller

spring-context/src/main/java/org/springframework/context/config/PropertyPlaceholderBeanDefinitionParser.java

@@ -33,7 +33,7 @@
  */
 class PropertyPlaceholderBeanDefinitionParser extends AbstractPropertyLoadingBeanDefinitionParser {
 
-	private static final String SYSTEM_PROPERTIES_MODE_ATTRIB = "system-properties-mode";
+	private static final String SYSTEM_PROPERTIES_MODE_ATTRIBUTE = "system-properties-mode";
 
 	private static final String SYSTEM_PROPERTIES_MODE_DEFAULT = "ENVIRONMENT";
 
@@ -43,13 +43,13 @@ protected Class<?> getBeanClass(Element element) {
 		// As of Spring 3.1, the default value of system-properties-mode has changed from
 		// 'FALLBACK' to 'ENVIRONMENT'. This latter value indicates that resolution of
 		// placeholders against system properties is a function of the Environment and
-		// its current set of PropertySources
-		if (element.getAttribute(SYSTEM_PROPERTIES_MODE_ATTRIB).equals(SYSTEM_PROPERTIES_MODE_DEFAULT)) {
+		// its current set of PropertySources.
+		if (SYSTEM_PROPERTIES_MODE_DEFAULT.equals(element.getAttribute(SYSTEM_PROPERTIES_MODE_ATTRIBUTE))) {
 			return PropertySourcesPlaceholderConfigurer.class;
 		}
 
-		// the user has explicitly specified a value for system-properties-mode. Revert
-		// to PropertyPlaceholderConfigurer to ensure backward compatibility.
+		// The user has explicitly specified a value for system-properties-mode: revert to
+		// PropertyPlaceholderConfigurer to ensure backward compatibility with 3.0 and earlier.
 		return PropertyPlaceholderConfigurer.class;
 	}
 
@@ -60,12 +60,16 @@ protected void doParse(Element element, BeanDefinitionBuilder builder) {
 		builder.addPropertyValue("ignoreUnresolvablePlaceholders",
 				Boolean.valueOf(element.getAttribute("ignore-unresolvable")));
 
-		String systemPropertiesModeName = element.getAttribute(SYSTEM_PROPERTIES_MODE_ATTRIB);
+		String systemPropertiesModeName = element.getAttribute(SYSTEM_PROPERTIES_MODE_ATTRIBUTE);
 		if (StringUtils.hasLength(systemPropertiesModeName) &&
 				!systemPropertiesModeName.equals(SYSTEM_PROPERTIES_MODE_DEFAULT)) {
 			builder.addPropertyValue("systemPropertiesModeName", "SYSTEM_PROPERTIES_MODE_" + systemPropertiesModeName);
 		}
 
+		if (element.hasAttribute("value-separator")) {
+			builder.addPropertyValue("valueSeparator", element.getAttribute("value-separator"));
+		}
+
 		if (element.hasAttribute("null-value")) {
 			builder.addPropertyValue("nullValue", element.getAttribute("null-value"));
 		}

spring-context/src/main/resources/org/springframework/context/config/spring-context-4.2.xsd

@@ -144,6 +144,14 @@
 							</xsd:restriction>
 						</xsd:simpleType>
 					</xsd:attribute>
+					<xsd:attribute name="value-separator" default=":">
+						<xsd:annotation>
+							<xsd:documentation><![CDATA[
+	The separating character between the placeholder variable and the associated
+	default value: by default, a ':' symbol.
+				]]></xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
 					<xsd:attribute name="null-value">
 						<xsd:annotation>
 							<xsd:documentation><![CDATA[

spring-context/src/test/java/org/springframework/context/config/ContextNamespaceHandlerTests.java

@@ -38,6 +38,7 @@
  * @author Arjen Poutsma
  * @author Dave Syer
  * @author Chris Beams
+ * @author Juergen Hoeller
  * @since 2.5.6
  */
 public class ContextNamespaceHandlerTests {
@@ -55,8 +56,7 @@ public void propertyPlaceholder() throws Exception {
 		Map<String, PlaceholderConfigurerSupport> beans = applicationContext
 				.getBeansOfType(PlaceholderConfigurerSupport.class);
 		assertFalse("No PropertyPlaceholderConfigurer found", beans.isEmpty());
-		String s = (String) applicationContext.getBean("string");
-		assertEquals("bar", s);
+		assertEquals("bar", applicationContext.getBean("string"));
 		assertEquals("null", applicationContext.getBean("nullString"));
 	}
 
@@ -69,11 +69,11 @@ public void propertyPlaceholderSystemProperties() throws Exception {
 			Map<String, PropertyPlaceholderConfigurer> beans = applicationContext
 					.getBeansOfType(PropertyPlaceholderConfigurer.class);
 			assertFalse("No PropertyPlaceholderConfigurer found", beans.isEmpty());
-			String s = (String) applicationContext.getBean("string");
-			assertEquals("spam", s);
+			assertEquals("spam", applicationContext.getBean("string"));
+			assertEquals("none", applicationContext.getBean("fallback"));
 		}
 		finally {
-			if (value!=null) {
+			if (value != null) {
 				System.setProperty("foo", value);
 			}
 		}
@@ -89,8 +89,8 @@ public void propertyPlaceholderEnvironmentProperties() throws Exception {
 		Map<String, PlaceholderConfigurerSupport> beans = applicationContext
 				.getBeansOfType(PlaceholderConfigurerSupport.class);
 		assertFalse("No PropertyPlaceholderConfigurer found", beans.isEmpty());
-		String s = (String) applicationContext.getBean("string");
-		assertEquals("spam", s);
+		assertEquals("spam", applicationContext.getBean("string"));
+		assertEquals("none", applicationContext.getBean("fallback"));
 	}
 
 	@Test
@@ -100,12 +100,9 @@ public void propertyPlaceholderLocation() throws Exception {
 		Map<String, PropertyPlaceholderConfigurer> beans = applicationContext
 				.getBeansOfType(PropertyPlaceholderConfigurer.class);
 		assertFalse("No PropertyPlaceholderConfigurer found", beans.isEmpty());
-		String s = (String) applicationContext.getBean("foo");
-		assertEquals("bar", s);
-		s = (String) applicationContext.getBean("bar");
-		assertEquals("foo", s);
-		s = (String) applicationContext.getBean("spam");
-		assertEquals("maps", s);
+		assertEquals("bar", applicationContext.getBean("foo"));
+		assertEquals("foo", applicationContext.getBean("bar"));
+		assertEquals("maps", applicationContext.getBean("spam"));
 	}
 
 	@Test
@@ -115,8 +112,7 @@ public void propertyPlaceholderIgnored() throws Exception {
 		Map<String, PlaceholderConfigurerSupport> beans = applicationContext
 				.getBeansOfType(PlaceholderConfigurerSupport.class);
 		assertFalse("No PropertyPlaceholderConfigurer found", beans.isEmpty());
-		String s = (String) applicationContext.getBean("string");
-		assertEquals("${bar}", s);
+		assertEquals("${bar}", applicationContext.getBean("string"));
 		assertEquals("null", applicationContext.getBean("nullString"));
 	}
 

spring-context/src/test/resources/org/springframework/context/config/contextNamespaceHandlerTests-simple.xml

@@ -11,4 +11,8 @@
 		<constructor-arg value="${foo}"/>
 	</bean>
 
+	<bean id="fallback" class="java.lang.String">
+		<constructor-arg value="${bar:none}"/>
+	</bean>
+
 </beans>

spring-context/src/test/resources/org/springframework/context/config/contextNamespaceHandlerTests-system.xml

@@ -2,18 +2,22 @@
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
 	xmlns:util="http://www.springframework.org/schema/util"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
-				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
-				http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.5.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
+				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd
+				http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd">
 
 	<util:properties id="placeholderProps">
 		<prop key="foo">bar</prop>
 	</util:properties>
 
-	<context:property-placeholder properties-ref="placeholderProps" system-properties-mode="OVERRIDE"/>
+	<context:property-placeholder properties-ref="placeholderProps" system-properties-mode="OVERRIDE" value-separator="?"/>
 
 	<bean id="string" class="java.lang.String">
 		<constructor-arg value="${foo}"/>
 	</bean>
 
+	<bean id="fallback" class="java.lang.String">
+		<constructor-arg value="${bar?none}"/>
+	</bean>
+
 </beans>