<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.example</groupId>
 <artifactId>demo</artifactId>
 <packaging>war</packaging>
 <version>1.0-SNAPSHOT</version>
 <name>demo Maven Webapp</name>
 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>1.5.1.RELEASE</version>
  <relativePath/>
 </parent>
 <properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  <java.version>1.8</java.version>
  <spring-boot-admin.version>1.4.5</spring-boot-admin.version>
 </properties>
 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>3.8.1</version>
   <scope>test</scope>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-actuator</artifactId>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
  </dependency>
  <dependency>
   <groupId>de.codecentric</groupId>
   <artifactId>spring-boot-admin-starter-client</artifactId>
   <version>${spring-boot-admin.version}</version>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter</artifactId>
  </dependency>
 </dependencies>
 <build>
  <plugins>
   <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
   </plugin>
   <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin </artifactId>
    <dependencies>
     <!--springloaded hot deploy -->
     <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>springloaded</artifactId>
      <systemPath>${basedir}/src/main/webapp/WEB-INF/lib/springloaded-1.2.5.RELEASE.jar</systemPath>
     </dependency>
    </dependencies>
    <executions>
     <execution>
      <goals>
       <goal>repackage</goal>
      </goals>
      <configuration>
       <classifier>exec</classifier>
      </configuration>
     </execution>
    </executions>
   </plugin>
  </plugins>
 </build>
</project>

@Configuration，@EnableAutoConfiguration和@ComponentScan
package com;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.scheduling.annotation.EnableAsync;
@SpringBootApplication
@EnableAsync
public class Application implements EmbeddedServletContainerCustomizer {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
  @Override
  public void customize(ConfigurableEmbeddedServletContainer configurableEmbeddedServletContainer) {
    configurableEmbeddedServletContainer.setPort(8087);
  }
}

package com.example;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * Created by Administrator on 2017/4/24.
 */
@RestController
@RequestMapping("/")
public class DemoController {
  @RequestMapping("/demo")
  private String demo() {
    return "this is spring boot demo!!!";
  }
}