Add configuration properties validation sample

Create a new project sample that demonstrate the usage of
@ConfigurationProperties with configurationPropertiesValidator.

Fixes gh-3513

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -782,7 +782,9 @@ annotations to your `@ConfigurationProperties` class:
 ----
 
 You can also add a custom Spring `Validator` by creating a bean definition called
-`configurationPropertiesValidator`.
+`configurationPropertiesValidator`. There is a
+{github-code}/spring-boot-samples/spring-boot-sample-property-validation[Validation sample]
+so you can see how to set things up.
 
 TIP: The `spring-boot-actuator` module includes an endpoint that exposes all
 `@ConfigurationProperties` beans. Simply point your web browser to `/configprops`

spring-boot-samples/README.adoc

@@ -70,6 +70,8 @@
   -- A spring integration application
 * link:spring-boot-sample-profile[spring-boot-sample-profile]
   -- example showing Spring's `@profile` support
+* link:spring-boot-sample-property-validation[spring-boot-sample-property-validation]
+  -- example showing the usage of @ConfigurationProperties` with a Spring's `Validator`
 * link:spring-boot-sample-parent-context[spring-boot-sample-parent-context]
   -- example showing an `ApplicationContext` with a parent
 * link:spring-boot-sample-aop[spring-boot-sample-aop]

spring-boot-samples/pom.xml

@@ -67,6 +67,7 @@
 		<module>spring-boot-sample-metrics-redis</module>
 		<module>spring-boot-sample-parent-context</module>
 		<module>spring-boot-sample-profile</module>
+		<module>spring-boot-sample-property-validation</module>
 		<module>spring-boot-sample-secure</module>
 		<module>spring-boot-sample-secure-oauth2</module>
 		<module>spring-boot-sample-servlet</module>

spring-boot-samples/spring-boot-sample-property-validation/application.properties

+host: 192.168.0.1
+port: 8080
\ No newline at end of file

spring-boot-samples/spring-boot-sample-property-validation/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-property-validation'
+	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")
+	compile("org.hibernate:hibernate-validator")
+	testCompile("org.springframework.boot:spring-boot-starter-test")
+}
+
+task wrapper(type: Wrapper) {
+	gradleVersion = '1.6'
+}

spring-boot-samples/spring-boot-sample-property-validation/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-property-validation</artifactId>
+	<name>Spring Boot Property Validation Sample</name>
+	<description>Spring Boot Property Validation 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.hibernate</groupId>
+			<artifactId>hibernate-validator</artifactId>
+			<version>5.1.3.Final</version>
+		</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-property-validation/src/main/java/sample/propertyvalidation/ConfigurationPropertiesValidator.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.propertyvalidation;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.stereotype.Component;
+import org.springframework.validation.Errors;
+import org.springframework.validation.ValidationUtils;
+import org.springframework.validation.Validator;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+@Component(value = "configurationPropertiesValidator")
+public class ConfigurationPropertiesValidator implements Validator {
+
+	public static final String IP_REGEX = "^(?:[0-9]{1,3}\\.){3}[0-9]{1,3}$";
+
+	final Pattern pattern = Pattern.compile(IP_REGEX);
+
+	private Set<String> validatedClasses = new HashSet<String>() {{
+		add(SampleProperties.class.getName());
+	}};
+
+	@Override
+	public boolean supports(Class<?> aClass) {
+		return AnnotationUtils.findAnnotation(aClass, ConfigurationProperties.class) != null;
+	}
+
+	@Override
+	public void validate(Object o, Errors errors) {
+		if(validatedClasses.contains(o.getClass().getName())) {
+			doValidation(o, errors);
+		}
+	}
+
+	private void doValidation(Object o, Errors errors) {
+		ValidationUtils.rejectIfEmpty(errors, "host", "host.empty");
+		ValidationUtils.rejectIfEmpty(errors, "port", "port.empty");
+
+		SampleProperties properties = (SampleProperties) o;
+		if(!pattern.matcher(properties.getHost()).matches()) {
+			errors.rejectValue("host", "Invalid host");
+		}
+	}
+
+}

spring-boot-samples/spring-boot-sample-property-validation/src/main/java/sample/propertyvalidation/SampleProperties.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.propertyvalidation;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+@Component
+@ConfigurationProperties
+public class SampleProperties {
+
+	private String host;
+
+	private Integer port;
+
+	public String getHost() {
+		return host;
+	}
+
+	public void setHost(String host) {
+		this.host = host;
+	}
+
+	public Integer getPort() {
+		return port;
+	}
+
+	public void setPort(Integer port) {
+		this.port = port;
+	}
+}

spring-boot-samples/spring-boot-sample-property-validation/src/main/java/sample/propertyvalidation/SamplePropertyValidationApplication.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.propertyvalidation;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+
+@SpringBootApplication
+@EnableConfigurationProperties
+public class SamplePropertyValidationApplication implements CommandLineRunner {
+
+	@Autowired
+	private SampleProperties properties;
+
+	@Override
+	public void run(String... args) {
+		System.out.println("host: " + this.properties.getHost());
+		System.out.println("port:" + this.properties.getPort());
+	}
+
+	public static void main(String[] args) throws Exception {
+		SpringApplication.run(SamplePropertyValidationApplication.class, args);
+	}
+
+}

spring-boot-samples/spring-boot-sample-property-validation/src/main/resources/application.properties

+host: 192.168.0.1
+port: 8080
\ No newline at end of file

spring-boot-samples/spring-boot-sample-property-validation/src/test/java/sample/propertyvalidation/SamplePropertyValidationApplicationTests.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.propertyvalidation;
+
+import org.junit.Test;
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.validation.Validator;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests for {@link SamplePropertyValidationApplication}.
+ *
+ * @author Lucas Saldanha
+ */
+public class SamplePropertyValidationApplicationTests {
+
+	private final AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+
+	@Test
+	public void testBindingValidProperties() {
+		this.context.register(TestConfiguration.class);
+		EnvironmentTestUtils.addEnvironment(this.context, "host:192.168.0.1");
+		EnvironmentTestUtils.addEnvironment(this.context, "port:8080");
+		this.context.refresh();
+
+		assertEquals(1, this.context.getBeanNamesForType(SampleProperties.class).length);
+		SampleProperties properties = this.context.getBean(SampleProperties.class);
+		assertEquals("192.168.0.1", properties.getHost());
+		assertEquals(8080, (int) properties.getPort());
+	}
+
+	@Test(expected = BeanCreationException.class)
+	public void testBindingInvalidProperties() {
+		this.context.register(TestConfiguration.class);
+		EnvironmentTestUtils.addEnvironment(this.context, "host:xxxxxx");
+		EnvironmentTestUtils.addEnvironment(this.context, "port:8080");
+		this.context.refresh();
+	}
+
+	@Test
+	public void testBindingValidPropertiesWithMultipleConfigurationPropertiesClasses() {
+		this.context.register(TestConfiguration.class);
+		this.context.register(ServerProperties.class);
+		EnvironmentTestUtils.addEnvironment(this.context, "host:192.168.0.1");
+		EnvironmentTestUtils.addEnvironment(this.context, "port:8080");
+		this.context.refresh();
+
+		assertEquals(1, this.context.getBeanNamesForType(SampleProperties.class).length);
+		SampleProperties properties = this.context.getBean(SampleProperties.class);
+		assertEquals("192.168.0.1", properties.getHost());
+		assertEquals(8080, (int) properties.getPort());
+	}
+
+	@Configuration
+	@EnableConfigurationProperties(SampleProperties.class)
+	protected static class TestConfiguration {
+
+		@Bean
+		public Validator configurationPropertiesValidator() {
+			return new ConfigurationPropertiesValidator();
+		}
+	}
+
+}

spring-boot-samples/spring-boot-sample-property-validation/src/test/resources/application.properties

+host: 192.168.0.1
+port: 8080
\ No newline at end of file