Added exceptionIfInvalid attribute to @ConfigurationProperties

Default behaviour unchanged, but if you want to ignore validation errors
you can switch them off for indivdual beans now.

Fixes gh-144

spring-boot/src/main/java/org/springframework/boot/bind/PropertiesConfigurationFactory.java

@@ -173,6 +173,12 @@ public class PropertiesConfigurationFactory<T> implements FactoryBean<T>,
 		this.validator = validator;
 	}
 
+	/**
+	 * Flag to indicate that an exception should be raised if a Validator is available and
+	 * validation fails.
+	 * 
+	 * @param exceptionIfInvalid the flag to set
+	 */
 	public void setExceptionIfInvalid(boolean exceptionIfInvalid) {
 		this.exceptionIfInvalid = exceptionIfInvalid;
 	}

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationProperties.java

@@ -72,6 +72,13 @@ public @interface ConfigurationProperties {
 	 */
 	boolean ignoreUnknownFields() default true;
 
+	/**
+	 * Flag to indicate that validation errors can be swallowed. If set they will be
+	 * logged, but not propagate to the caller.
+	 * @return the flag value (default true)
+	 */
+	boolean exceptionIfInvalid() default true;
+
 	/**
 	 * Optionally provide an explicit resource path to bind to instead of using the
 	 * default environment.

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessor.java

@@ -302,6 +302,7 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 		if (annotation != null) {
 			factory.setIgnoreInvalidFields(annotation.ignoreInvalidFields());
 			factory.setIgnoreUnknownFields(annotation.ignoreUnknownFields());
+			factory.setExceptionIfInvalid(annotation.exceptionIfInvalid());
 			factory.setIgnoreNestedProperties(annotation.ignoreNestedProperties());
 			String targetName = (StringUtils.hasLength(annotation.value()) ? annotation
 					.value() : annotation.name());

spring-boot/src/test/java/org/springframework/boot/bind/PropertiesConfigurationFactoryTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.bind;
 
+import java.io.IOException;
+
 import javax.validation.Validation;
 import javax.validation.constraints.NotNull;
 
@@ -85,6 +87,15 @@ public class PropertiesConfigurationFactoryTests {
 		createFoo("bar: blah");
 	}
 
+	@Test
+	public void testValidationErrorCanBeSuppressed() throws Exception {
+		this.validator = new SpringValidatorAdapter(Validation
+				.buildDefaultValidatorFactory().getValidator());
+		setupFactory();
+		this.factory.setExceptionIfInvalid(false);
+		bindFoo("bar: blah");
+	}
+
 	@Test
 	public void testBindToNamedTarget() throws Exception {
 		this.targetName = "foo";
@@ -93,15 +104,23 @@ public class PropertiesConfigurationFactoryTests {
 	}
 
 	private Foo createFoo(final String values) throws Exception {
-		this.factory = new PropertiesConfigurationFactory<Foo>(Foo.class);
+		setupFactory();
+		return bindFoo(values);
+	}
+
+	private Foo bindFoo(final String values) throws Exception {
 		this.factory.setProperties(PropertiesLoaderUtils
 				.loadProperties(new ByteArrayResource(values.getBytes())));
+		this.factory.afterPropertiesSet();
+		return this.factory.getObject();
+	}
+
+	private void setupFactory() throws IOException {
+		this.factory = new PropertiesConfigurationFactory<Foo>(Foo.class);
 		this.factory.setValidator(this.validator);
 		this.factory.setTargetName(this.targetName);
 		this.factory.setIgnoreUnknownFields(this.ignoreUnknownFields);
 		this.factory.setMessageSource(new StaticMessageSource());
-		this.factory.afterPropertiesSet();
-		return this.factory.getObject();
 	}
 
 	// Foo needs to be public and to have setters for all properties

spring-boot/src/test/java/org/springframework/boot/context/properties/EnableConfigurationPropertiesTests.java

@@ -21,9 +21,13 @@ import java.util.Arrays;
 import java.util.List;
 
 import javax.annotation.PostConstruct;
+import javax.validation.constraints.NotNull;
 
+import org.hamcrest.Matchers;
 import org.junit.After;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.TestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -31,6 +35,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.ImportResource;
 import org.springframework.stereotype.Component;
+import org.springframework.validation.BindException;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -44,6 +49,9 @@ public class EnableConfigurationPropertiesTests {
 
 	private AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
 
+	@Rule
+	public ExpectedException expected = ExpectedException.none();
+
 	@After
 	public void close() {
 		System.clearProperty("name");
@@ -111,6 +119,26 @@ public class EnableConfigurationPropertiesTests {
 		assertEquals("foo", this.context.getBean(TestProperties.class).name);
 	}
 
+	@Test
+	public void testExceptionOnValidation() {
+		this.context.register(ExceptionIfInvalidTestConfiguration.class);
+		TestUtils.addEnviroment(this.context, "name:foo");
+		this.expected.expectCause(Matchers.<Throwable> instanceOf(BindException.class));
+		this.context.refresh();
+	}
+
+	@Test
+	public void testNoExceptionOnValidation() {
+		this.context.register(NoExceptionIfInvalidTestConfiguration.class);
+		TestUtils.addEnviroment(this.context, "name:foo");
+		this.context.refresh();
+		assertEquals(
+				1,
+				this.context
+						.getBeanNamesForType(NoExceptionIfInvalidTestProperties.class).length);
+		assertEquals("foo", this.context.getBean(TestProperties.class).name);
+	}
+
 	@Test
 	public void testNestedPropertiesBinding() {
 		this.context.register(NestedConfiguration.class);
@@ -264,6 +292,16 @@ public class EnableConfigurationPropertiesTests {
 	protected static class IgnoreNestedTestConfiguration {
 	}
 
+	@Configuration
+	@EnableConfigurationProperties(ExceptionIfInvalidTestProperties.class)
+	protected static class ExceptionIfInvalidTestConfiguration {
+	}
+
+	@Configuration
+	@EnableConfigurationProperties(NoExceptionIfInvalidTestProperties.class)
+	protected static class NoExceptionIfInvalidTestConfiguration {
+	}
+
 	@Configuration
 	@EnableConfigurationProperties(DerivedProperties.class)
 	protected static class DerivedConfiguration {
@@ -379,6 +417,38 @@ public class EnableConfigurationPropertiesTests {
 
 	}
 
+	@ConfigurationProperties
+	protected static class ExceptionIfInvalidTestProperties extends TestProperties {
+
+		@NotNull
+		private String description;
+
+		public String getDescription() {
+			return this.description;
+		}
+
+		public void setDescription(String description) {
+			this.description = description;
+		}
+
+	}
+
+	@ConfigurationProperties(exceptionIfInvalid = false)
+	protected static class NoExceptionIfInvalidTestProperties extends TestProperties {
+
+		@NotNull
+		private String description;
+
+		public String getDescription() {
+			return this.description;
+		}
+
+		public void setDescription(String description) {
+			this.description = description;
+		}
+
+	}
+
 	protected static class MoreProperties {
 		private String name;