Polish "Fix handling of empty/null arguments"

Closes gh-9916

Author: snicoll

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

@@ -18,11 +18,10 @@
 
 import java.util.Arrays;
 import java.util.LinkedList;
+import java.util.Objects;
 
 import org.codehaus.plexus.util.cli.CommandLineUtils;
 
-import org.springframework.util.StringUtils;
-
 /**
  * Parse and expose arguments specified in a single string.
  *
@@ -41,7 +40,7 @@ class RunArguments {
 
 	RunArguments(String[] args) {
 		if (args != null) {
-			Arrays.stream(args).filter(StringUtils::hasLength).forEach(this.args::add);
+			Arrays.stream(args).filter(Objects::nonNull).forEach(this.args::add);
 		}
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -43,9 +43,16 @@ public void parseNullArray() {
 
 	@Test
 	public void parseArrayContainingNullValue() {
-		String[] args = new RunArguments(new String[]{null}).asArray();
+		String[] args = new RunArguments(new String[]{"foo", null, "bar"}).asArray();
 		assertThat(args).isNotNull();
-		assertThat(args.length).isEqualTo(0);
+		assertThat(args).containsOnly("foo", "bar");
+	}
+
+	@Test
+	public void parseArrayContainingEmptyValue() {
+		String[] args = new RunArguments(new String[]{"foo", "", "bar"}).asArray();
+		assertThat(args).isNotNull();
+		assertThat(args).containsOnly("foo", "", "bar");
 	}
 
 	@Test