Add a FailureAnalyzer for BeanNotOfRequiredTypeException

Closes gh-6434

spring-boot/src/main/java/org/springframework/boot/diagnostics/analyzer/BeanNotOfRequiredTypeFailureAnalyzer.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-2016 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.diagnostics.analyzer;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.lang.reflect.Proxy;
+
+import org.springframework.beans.factory.BeanNotOfRequiredTypeException;
+import org.springframework.boot.diagnostics.AbstractFailureAnalyzer;
+import org.springframework.boot.diagnostics.FailureAnalysis;
+
+/**
+ * An {@link AbstractFailureAnalyzer} that performs analysis of failures caused by a
+ * {@link BeanNotOfRequiredTypeFailureAnalyzer}.
+ *
+ * @author Andy Wilkinson
+ */
+public class BeanNotOfRequiredTypeFailureAnalyzer
+		extends AbstractFailureAnalyzer<BeanNotOfRequiredTypeException> {
+
+	private static final String ACTION = "Consider injecting the bean as one of its "
+			+ "interfaces or forcing the use of CGLib-based "
+			+ "proxies by setting proxyTargetClass=true on @EnableAsync and/or "
+			+ "@EnableCaching.";
+
+	@Override
+	protected FailureAnalysis analyze(Throwable rootFailure,
+			BeanNotOfRequiredTypeException cause) {
+		if (!Proxy.isProxyClass(cause.getActualType())) {
+			return null;
+		}
+		return new FailureAnalysis(getDescription(cause), ACTION, cause);
+	}
+
+	private String getDescription(BeanNotOfRequiredTypeException ex) {
+		StringWriter description = new StringWriter();
+		PrintWriter printer = new PrintWriter(description);
+		printer.printf(
+				"The bean '%s' could not be injected as a '%s' because it is a "
+						+ "JDK dynamic proxy that implements:%n",
+				ex.getBeanName(), ex.getRequiredType().getName());
+		for (Class<?> iface : ex.getRequiredType().getInterfaces()) {
+			printer.println("\t" + iface.getName());
+		}
+		return description.toString();
+	}
+
+}

spring-boot/src/main/resources/META-INF/spring.factories

@@ -34,6 +34,7 @@ org.springframework.boot.env.SpringApplicationJsonEnvironmentPostProcessor
 # Failure Analyzers
 org.springframework.boot.diagnostics.FailureAnalyzer=\
 org.springframework.boot.diagnostics.analyzer.BeanCurrentlyInCreationFailureAnalyzer,\
+org.springframework.boot.diagnostics.analyzer.BeanNotOfRequiredTypeFailureAnalyzer,\
 org.springframework.boot.diagnostics.analyzer.BindFailureAnalyzer,\
 org.springframework.boot.diagnostics.analyzer.NoUniqueBeanDefinitionFailureAnalyzer,\
 org.springframework.boot.diagnostics.analyzer.PortInUseFailureAnalyzer,\

spring-boot/src/test/java/org/springframework/boot/diagnostics/analyzer/BeanNotOfRequiredTypeFailureAnalyzerTests.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright 2012-2016 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.diagnostics.analyzer;
+
+import org.junit.Test;
+
+import org.springframework.boot.diagnostics.FailureAnalysis;
+import org.springframework.boot.diagnostics.FailureAnalyzer;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.scheduling.annotation.EnableAsync;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+
+/**
+ * Tests for {@link BeanNotOfRequiredTypeFailureAnalyzer}.
+ *
+ * @author Andy Wilkinson
+ */
+public class BeanNotOfRequiredTypeFailureAnalyzerTests {
+
+	private final FailureAnalyzer analyzer = new BeanNotOfRequiredTypeFailureAnalyzer();
+
+	@Test
+	public void jdkProxyCausesInjectionFailure() {
+		FailureAnalysis analysis = performAnalysis(JdkProxyConfiguration.class);
+		assertThat(analysis.getDescription()).startsWith("The bean 'asyncBean'");
+		assertThat(analysis.getDescription())
+				.contains("'" + AsyncBean.class.getName() + "'");
+		assertThat(analysis.getDescription())
+				.endsWith(String.format("%s%n", SomeInterface.class.getName()));
+	}
+
+	private FailureAnalysis performAnalysis(Class<?> configuration) {
+		FailureAnalysis analysis = this.analyzer.analyze(createFailure(configuration));
+		assertThat(analysis).isNotNull();
+		return analysis;
+	}
+
+	private Exception createFailure(Class<?> configuration) {
+		ConfigurableApplicationContext context = null;
+		try {
+			context = new AnnotationConfigApplicationContext(configuration);
+		}
+		catch (Exception ex) {
+			return ex;
+		}
+		finally {
+			if (context != null) {
+				context.close();
+			}
+		}
+		fail("Expected failure did not occur");
+		return null;
+	}
+
+	@Configuration
+	@EnableAsync
+	@Import(UserConfiguration.class)
+	static class JdkProxyConfiguration {
+
+		@Bean
+		public AsyncBean asyncBean() {
+			return new AsyncBean();
+		}
+	}
+
+	@Configuration
+	static class UserConfiguration {
+
+		@Bean
+		public AsyncBeanUser user(AsyncBean bean) {
+			return new AsyncBeanUser(bean);
+		}
+
+	}
+
+	static class AsyncBean implements SomeInterface {
+
+		@Async
+		public void foo() {
+
+		}
+
+		@Override
+		public void bar() {
+
+		}
+
+	}
+
+	interface SomeInterface {
+
+		void bar();
+
+	}
+
+	static class AsyncBeanUser {
+
+		AsyncBeanUser(AsyncBean asyncBean) {
+		}
+
+	}
+
+}