Properly handle values with spaces

Closes gh-10741

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AbstractRunMojo.java

@@ -569,18 +569,14 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 	 */
 	static class SystemPropertyFormatter {
 
-		private static final String NO_VALUE_FORMAT = "-D%s";
-
-		private static final String KEY_VALUE_FORMAT = NO_VALUE_FORMAT + "=%s";
-
 		public static String format(Object key, Object value) {
 			if (key == null) {
 				return "";
 			}
-			if (value == null || String.valueOf(value).trim().isEmpty()) {
-				return String.format(NO_VALUE_FORMAT, key);
+			if (value == null || String.valueOf(value).isEmpty()) {
+				return String.format("-D%s", key);
 			}
-			return String.format(KEY_VALUE_FORMAT, key, value);
+			return String.format("-D%s=\"%s\"", key, value);
 		}
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/site/apt/examples/run-env-variables.apt.vm

@@ -39,7 +39,8 @@ Dmytro Nosan
 ---
 
   If the value is empty or not defined (i.e. <<<<MY_ENV/>>>>), the env variable is set
-  with an empty String as the value.
+  with an empty String as the value. Maven trims values specified in the pom so it is
+  not possible to specify a env variable who needs to start or end with a space.
 
   Any String typed Maven variable can be passed as system properties. Any attempt to pass
   any other Maven variable type (e.g. a <<<List>>> or a <<<URL>>> variable) will cause the

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/site/apt/examples/run-system-properties.apt.vm

@@ -40,7 +40,9 @@
 ---
 
   If the value is empty or not defined (i.e. <<<<my-property/>>>>), the system property
-  is set with an empty String as the value.
+  is set with an empty String as the value. Maven trims values specified in the pom so it
+  is not possible to specify a System property who needs to start or end with a space via
+  this mechanism: consider using <<<jvmArguments>> instead.
 
   Any String typed Maven variable can be passed as system properties. Any attempt to pass
   any other Maven variable type (e.g. a <<<List>>> or a <<<URL>>> variable) will cause the

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/SystemPropertyFormatterTests.java

@@ -40,7 +40,7 @@ public class SystemPropertyFormatterTests {
 	@Test
 	public void parseKeyWithValue() {
 		assertThat(SystemPropertyFormatter.format("key1", "value1"))
-				.isEqualTo("-Dkey1=value1");
+				.isEqualTo("-Dkey1=\"value1\"");
 	}
 
 	@Test
@@ -48,4 +48,10 @@ public class SystemPropertyFormatterTests {
 		assertThat(SystemPropertyFormatter.format("key1", "")).isEqualTo("-Dkey1");
 	}
 
+	@Test
+	public void parseKeyWithOnlySpace() {
+		assertThat(SystemPropertyFormatter.format("key1", "   "))
+				.isEqualTo("-Dkey1=\"   \"");
+	}
+
 }