Add random.* property source

spring-boot/src/main/java/org/springframework/boot/context/initializer/ConfigFileApplicationContextInitializer.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Random;
 import java.util.Set;
 
 import org.springframework.beans.PropertyValues;
@@ -40,10 +41,12 @@ import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.PropertySource;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.DigestUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -106,6 +109,9 @@ public class ConfigFileApplicationContextInitializer implements
 		if (this.environment instanceof ConfigurableEnvironment) {
 			ConfigurableEnvironment environment = (ConfigurableEnvironment) this.environment;
 			load(environment, new DefaultResourceLoader());
+			environment.getPropertySources().addAfter(
+					StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME,
+					new RandomValuePropertySource("random"));
 			// Set bean properties from the early environment
 			PropertyValues propertyValues = new PropertySourcesPropertyValues(
 					environment.getPropertySources());
@@ -251,4 +257,28 @@ public class ConfigFileApplicationContextInitializer implements
 		this.searchLocations = (searchLocations == null ? null : searchLocations.clone());
 	}
 
+	private static class RandomValuePropertySource extends PropertySource<Random> {
+
+		public RandomValuePropertySource(String name) {
+			super(name, new Random());
+		}
+
+		@Override
+		public Object getProperty(String name) {
+			if (!name.startsWith("random.")) {
+				return null;
+			}
+			if (name.endsWith("int")) {
+				return getSource().nextInt();
+			}
+			if (name.endsWith("long")) {
+				return getSource().nextLong();
+			}
+			byte[] bytes = new byte[32];
+			getSource().nextBytes(bytes);
+			return DigestUtils.md5DigestAsHex(bytes);
+		}
+
+	}
+
 }

spring-boot/src/test/java/org/springframework/boot/context/initializer/ConfigFileApplicationContextInitializerTests.java

@@ -21,11 +21,14 @@ import java.util.Map;
 
 import org.junit.After;
 import org.junit.Test;
+import org.springframework.boot.SpringApplication;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.core.env.MapPropertySource;
 import org.springframework.core.env.SimpleCommandLinePropertySource;
+import org.springframework.core.env.StandardEnvironment;
 
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 import static org.junit.Assert.assertThat;
 
@@ -54,6 +57,15 @@ public class ConfigFileApplicationContextInitializerTests {
 		assertThat(property, equalTo("frompropertiesfile"));
 	}
 
+	@Test
+	public void randomValue() throws Exception {
+		StandardEnvironment environment = new StandardEnvironment();
+		this.initializer.setEnvironment(environment);
+		this.initializer.initialize(new SpringApplication(), new String[0]);
+		String property = environment.getProperty("random.value");
+		assertThat(property, notNullValue());
+	}
+
 	@Test
 	public void loadTwoPropertiesFiles() throws Exception {
 		this.initializer.setNames("testproperties,moreproperties");