Add support for UTF-8 in application.properties

Fixes gh-4622

spring-boot/src/main/java/org/springframework/boot/env/PropertiesPropertySourceLoader.java

@@ -22,6 +22,7 @@ import java.util.Properties;
 import org.springframework.core.env.PropertiesPropertySource;
 import org.springframework.core.env.PropertySource;
 import org.springframework.core.io.Resource;
+import org.springframework.core.io.support.EncodedResource;
 import org.springframework.core.io.support.PropertiesLoaderUtils;
 
 /**
@@ -41,7 +42,8 @@ public class PropertiesPropertySourceLoader implements PropertySourceLoader {
 	public PropertySource<?> load(String name, Resource resource, String profile)
 			throws IOException {
 		if (profile == null) {
-			Properties properties = PropertiesLoaderUtils.loadProperties(resource);
+			Properties properties = PropertiesLoaderUtils
+					.loadProperties(new EncodedResource(resource, "UTF-8"));
 			if (!properties.isEmpty()) {
 				return new PropertiesPropertySource(name, properties);
 			}

spring-boot/src/test/java/org/springframework/boot/env/PropertiesPropertySourceLoaderTests.java

@@ -46,6 +46,13 @@ public class PropertiesPropertySourceLoaderTests {
 		assertThat(source.getProperty("test"), equalTo((Object) "properties"));
 	}
 
+	@Test
+	public void loadPropertiesEncoded() throws Exception {
+		PropertySource<?> source = this.loader.load("encoded.properties",
+				new ClassPathResource("test-encoded.properties", getClass()), null);
+		assertThat(source.getProperty("test"), equalTo((Object) "prकperties"));
+	}
+
 	@Test
 	public void loadXml() throws Exception {
 		PropertySource<?> source = this.loader.load("test.xml",

spring-boot/src/test/resources/org/springframework/boot/env/test-encoded.properties

@@ -0,0 +1 @@
+test=prकperties