Improve error message on condition exceptions

Catch exceptions thrown from SpringBootCondition and re-throw with
more context.

See gh-1098

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/SpringBootCondition.java

@@ -21,6 +21,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.context.annotation.Condition;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.ClassMetadata;
 import org.springframework.core.type.MethodMetadata;
 import org.springframework.util.ClassUtils;
@@ -53,6 +54,22 @@ public abstract class SpringBootCondition implements Condition {
 							+ "springframework package (e.g. if you put a @ComponentScan "
 							+ "in the default package by mistake)", ex);
 		}
+		catch (RuntimeException ex) {
+			throw new IllegalStateException("Error processing condition on "
+					+ getName(metadata), ex);
+		}
+	}
+
+	private String getName(AnnotatedTypeMetadata metadata) {
+		if (metadata instanceof AnnotationMetadata) {
+			return ((AnnotationMetadata) metadata).getClassName();
+		}
+		if (metadata instanceof MethodMetadata) {
+			MethodMetadata methodMetadata = (MethodMetadata) metadata;
+			return methodMetadata.getDeclaringClassName() + "."
+					+ methodMetadata.getMethodName();
+		}
+		return metadata.toString();
 	}
 
 	private static String getClassOrMethodName(AnnotatedTypeMetadata metadata) {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/condition/SpringBootConditionTests.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2012-2014 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.boot.autoconfigure.condition;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.context.annotation.Conditional;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+
+/**
+ * Tests for {@link SpringBootCondition}.
+ * 
+ * @author Phillip Webb
+ */
+@SuppressWarnings("resource")
+public class SpringBootConditionTests {
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	@Test
+	public void sensibleClassException() {
+		this.thrown.expect(IllegalStateException.class);
+		this.thrown.expectMessage("Error processing condition on "
+				+ ErrorOnClass.class.getName());
+		new AnnotationConfigApplicationContext(ErrorOnClass.class);
+	}
+
+	@Test
+	public void sensibleMethodException() throws Exception {
+		this.thrown.expect(IllegalStateException.class);
+		this.thrown.expectMessage("Error processing condition on "
+				+ ErrorOnMethod.class.getName() + ".myBean");
+		new AnnotationConfigApplicationContext(ErrorOnMethod.class);
+	}
+
+	@Configuration
+	@Conditional(AlwaysThrowsCondition.class)
+	public static class ErrorOnClass {
+
+	}
+
+	@Configuration
+	public static class ErrorOnMethod {
+
+		@Bean
+		@Conditional(AlwaysThrowsCondition.class)
+		public String myBean() {
+			return "bean";
+		}
+
+	}
+
+	public static class AlwaysThrowsCondition extends SpringBootCondition {
+
+		@Override
+		public ConditionOutcome getMatchOutcome(ConditionContext context,
+				AnnotatedTypeMetadata metadata) {
+			throw new RuntimeException("Oh no!");
+		}
+
+	}
+
+}