Add logback sample application

Add a logback sample application to demonstrate how `logback-spring.xml`
can be used for customization.

See gh-2558

spring-boot-samples/pom.xml

@@ -55,6 +55,7 @@
 		<module>spring-boot-sample-jta-bitronix</module>
 		<module>spring-boot-sample-jta-jndi</module>
 		<module>spring-boot-sample-liquibase</module>
+		<module>spring-boot-sample-logback</module>
 		<module>spring-boot-sample-metrics-dropwizard</module>
 		<module>spring-boot-sample-metrics-opentsdb</module>
 		<module>spring-boot-sample-metrics-redis</module>

spring-boot-samples/spring-boot-sample-logback/build.gradle

+buildscript {
+	ext {
+		springBootVersion = '1.3.0.BUILD-SNAPSHOT'
+	}
+	repositories {
+		// NOTE: You should declare only repositories that you need here
+		mavenLocal()
+		mavenCentral()
+		maven { url "http://repo.spring.io/release" }
+		maven { url "http://repo.spring.io/milestone" }
+		maven { url "http://repo.spring.io/snapshot" }
+	}
+	dependencies {
+		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
+	}
+}
+
+apply plugin: 'java'
+apply plugin: 'eclipse'
+apply plugin: 'idea'
+apply plugin: 'spring-boot'
+
+jar {
+	baseName = 'spring-boot-sample-simple'
+	version =  '0.0.0'
+}
+
+run {
+  systemProperties = System.properties
+}
+
+repositories {
+	// NOTE: You should declare only repositories that you need here
+	mavenLocal()
+	mavenCentral()
+	maven { url "http://repo.spring.io/release" }
+	maven { url "http://repo.spring.io/milestone" }
+	maven { url "http://repo.spring.io/snapshot" }
+}
+
+dependencies {
+	compile("org.springframework.boot:spring-boot-starter")
+	testCompile("org.springframework.boot:spring-boot-starter-test")
+}
+
+task wrapper(type: Wrapper) {
+	gradleVersion = '1.6'
+}

spring-boot-samples/spring-boot-sample-logback/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<!-- Your own application should inherit from spring-boot-starter-parent -->
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-samples</artifactId>
+		<version>1.3.0.BUILD-SNAPSHOT</version>
+	</parent>
+	<artifactId>spring-boot-sample-logback</artifactId>
+	<name>Spring Boot Logback Sample</name>
+	<description>Spring Boot Logback Sample</description>
+	<url>http://projects.spring.io/spring-boot/</url>
+	<organization>
+		<name>Pivotal Software, Inc.</name>
+		<url>http://www.spring.io</url>
+	</organization>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-samples/spring-boot-sample-logback/src/main/java/sample/logback/SampleLogbackApplication.java

+/*
+ * Copyright 2012-2015 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 sample.logback;
+
+import javax.annotation.PostConstruct;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SampleLogbackApplication {
+
+	private static final Logger logger = LoggerFactory
+			.getLogger(SampleLogbackApplication.class);
+
+	@PostConstruct
+	public void logSomething() {
+		logger.debug("Sample Debug Message");
+		logger.trace("Sample Trace Message");
+	}
+
+	public static void main(String[] args) throws Exception {
+		SpringApplication.run(SampleLogbackApplication.class, args);
+	}
+
+}

spring-boot-samples/spring-boot-sample-logback/src/main/resources/logback-spring.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+	<include resource="org/springframework/boot/logging/logback/base.xml"/>
+	<logger name="sample.logback" level="DEBUG"/>
+</configuration>

spring-boot-samples/spring-boot-sample-logback/src/test/java/sample/logback/SampleLogbackApplicationTests.java

+/*
+ * 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 sample.logback;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.springframework.boot.test.OutputCapture;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+
+public class SampleLogbackApplicationTests {
+
+	@Rule
+	public OutputCapture outputCapture = new OutputCapture();
+
+	@Test
+	public void testLoadedCustomLogbackConfig() throws Exception {
+		SampleLogbackApplication.main(new String[0]);
+		this.outputCapture.expect(containsString("Sample Debug Message"));
+		this.outputCapture.expect(not(containsString("Sample Trace Message")));
+	}
+
+}