Ensure UPPER_CASE overrides work in PropertiesLauncher

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/PropertiesLauncher.java

@@ -132,17 +132,12 @@ public class PropertiesLauncher extends Launcher {
 	}
 
 	private void initializeProperties(File home) throws Exception, IOException {
-		String config = SystemPropertyUtils.resolvePlaceholders(System.getProperty(
-				CONFIG_NAME, "application")) + ".properties";
-		InputStream resource = getClasspathResource(config);
-		if (resource == null) {
-			resource = getResource(new File(home, config).getAbsolutePath());
-		}
-		if (resource == null) {
-			config = SystemPropertyUtils.resolvePlaceholders(System.getProperty(
-					CONFIG_LOCATION, config));
-			resource = getResource(config);
-		}
+		String config = "classpath:"
+				+ SystemPropertyUtils.resolvePlaceholders(SystemPropertyUtils
+						.getProperty(CONFIG_NAME, "application")) + ".properties";
+		config = SystemPropertyUtils.resolvePlaceholders(SystemPropertyUtils.getProperty(
+				CONFIG_LOCATION, config));
+		InputStream resource = getResource(config);
 
 		if (resource != null) {
 			this.logger.info("Found: " + config);

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/util/SystemPropertyUtils.java

@@ -147,21 +147,55 @@ public abstract class SystemPropertyUtils {
 
 	private static String resolvePlaceholder(Properties properties, String text,
 			String placeholderName) {
+		String propVal = getProperty(placeholderName, null, text);
+		if (propVal != null) {
+			return propVal;
+		}
+		return properties == null ? null : properties.getProperty(placeholderName);
+	}
+
+	public static String getProperty(String key) {
+		return getProperty(key, null, "");
+	}
+
+	public static String getProperty(String key, String defaultValue) {
+		return getProperty(key, defaultValue, "");
+	}
+
+	/**
+	 * Search the System properties and environment variables for a value with the
+	 * provided key. Environment variables in <code>UPPER_CASE</code> style are allowed
+	 * where System properties would normally be <code>lower.case</code>.
+	 * 
+	 * @param key the key to resolve
+	 * @param text optional extra context for an error message if the key resolution fails
+	 * (e.g. if System properties are not accessible)
+	 * @return a static property value or null of not found
+	 */
+	public static String getProperty(String key, String defaultValue, String text) {
 		try {
-			String propVal = System.getProperty(placeholderName);
+			String propVal = System.getProperty(key);
 			if (propVal == null) {
 				// Fall back to searching the system environment.
-				propVal = System.getenv(placeholderName);
+				propVal = System.getenv(key);
+			}
+			if (propVal == null) {
+				// Try with underscores.
+				propVal = System.getenv(key.replace(".", "_"));
+			}
+			if (propVal == null) {
+				// Try uppercase with underscores as well.
+				propVal = System.getenv(key.toUpperCase().replace(".", "_"));
 			}
 			if (propVal != null) {
 				return propVal;
 			}
 		}
 		catch (Throwable ex) {
-			System.err.println("Could not resolve placeholder '" + placeholderName
-					+ "' in [" + text + "] as system property: " + ex);
+			System.err.println("Could not resolve key '" + key + "' in '" + text
+					+ "' as system property or in environment: " + ex);
 		}
-		return properties == null ? null : properties.getProperty(placeholderName);
+		return defaultValue;
 	}
 
 	private static int findPlaceholderEndIndex(CharSequence buf, int startIndex) {

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/PropertiesLauncherTests.java

@@ -72,6 +72,15 @@ public class PropertiesLauncherTests {
 		assertEquals("[etc/]", ReflectionTestUtils.getField(launcher, "paths").toString());
 	}
 
+	@Test
+	public void testUserSpecifiedConfigPathWins() throws Exception {
+
+		System.setProperty("loader.config.name", "foo");
+		System.setProperty("loader.config.location", "classpath:bar.properties");
+		PropertiesLauncher launcher = new PropertiesLauncher();
+		assertEquals("my.BarApplication", launcher.getMainClass());
+	}
+
 	@Test
 	public void testSystemPropertySpecifiedMain() throws Exception {
 		System.setProperty("loader.main", "foo.Bar");

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/util/SystemPropertyUtilsTests.java

@@ -19,7 +19,6 @@ package org.springframework.boot.loader.util;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.springframework.boot.loader.util.SystemPropertyUtils;
 
 import static org.junit.Assert.assertEquals;
 
@@ -53,4 +52,9 @@ public class SystemPropertyUtilsTests {
 		assertEquals("foo", SystemPropertyUtils.resolvePlaceholders("${bar:${spam:foo}}"));
 	}
 
+	@Test
+	public void testEnvVar() {
+		assertEquals(System.getenv("LANG"), SystemPropertyUtils.getProperty("lang"));
+	}
+
 }

spring-boot-tools/spring-boot-loader/src/test/resources/bar.properties

@@ -0,0 +1 @@
+loader.main: my.BarApplication