Port the build to Gradle

Closes gh-19609
Closes gh-19608

spring-boot-project/spring-boot-devtools/src/intTest/java/com/example/ControllerOne.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class ControllerOne {
+
+	@RequestMapping("/one")
+	public String one() {
+		return "one";
+	}
+
+}

spring-boot-project/spring-boot-devtools/src/intTest/java/com/example/DevToolsTestApplication.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.context.WebServerPortFileWriter;
+
+@SpringBootApplication
+public class DevToolsTestApplication {
+
+	public static void main(String[] args) {
+		new SpringApplicationBuilder(DevToolsTestApplication.class).listeners(new WebServerPortFileWriter(args[0]))
+				.run(args);
+	}
+
+}