[Java] springboot项目突然启动缓慢的解决

• springboot项目突然启动缓慢
  
• springboot启动太慢优化
  
  
  
  • 1.组件自动扫描带来的问题（@SpringBootApplication）
    
  • 2.如何避免组件自动扫描带来的问题(不使用@SpringBootApplication)
    
  • 3.引发的问题——无法扫描组件
    
  • 4.千古红楼只一梦，竹篮打水一场空
    
  • 5.debugdebug，bugbug更健康
    
  • 6.分析Positivematches和Negativematches
    
  • 7.再次优化配置信息
    
  • 8.小结一下
    
  
  

package com.kfit.spring_boot_performance; 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration; 
import com.kfit.spring_boot_performance.controller.HelloController;
 
/**
 * @author Angel --守护天使
 * @version v.0.1
 * @date 2017年3月11日
 */
//移除 @SpringBootApplication and @ComponentScan, 用 @EnableAutoConfiguration 来替代
@Configuration
@EnableAutoConfiguration
public class App {   
  public static void main(String[] args) {
     SpringApplication.run(App.class, args);
  }
}

出现错误：There was an unexpected error (type=Not Found, status=404).

@Bean
 public HelloController helloController(){
   return new HelloController();
 }

spring-boot:run -Ddebug

=========================
AUTO-CONFIGURATION REPORT
=========================
Positive matches:
-----------------
DispatcherServletAutoConfiguration matched
- @ConditionalOnClass found required class 'org.springframework.web.servlet.DispatcherServlet' (OnClassCondition)
- @ConditionalOnWebApplication (required) found StandardServletEnvironment (OnWebApplicationCondition)
//此处省略剩下的打印信息…

DispatcherServletAutoConfiguration 
EmbeddedServletContainerAutoConfiguration 
ErrorMvcAutoConfiguration 
HttpEncodingAutoConfiguration 
HttpMessageConvertersAutoConfiguration 
JacksonAutoConfiguration 
JmxAutoConfiguration 
MultipartAutoConfiguration 
ServerPropertiesAutoConfiguration 
PropertyPlaceholderAutoConfiguration 
ThymeleafAutoConfiguration 
WebMvcAutoConfiguration 
WebSocketAutoConfiguration

@Configuration
@Import({
    DispatcherServletAutoConfiguration.class,
    EmbeddedServletContainerAutoConfiguration.class,
    ErrorMvcAutoConfiguration.class,
    HttpEncodingAutoConfiguration.class,
    HttpMessageConvertersAutoConfiguration.class,
    JacksonAutoConfiguration.class,
    JmxAutoConfiguration.class,
    MultipartAutoConfiguration.class,
    ServerPropertiesAutoConfiguration.class,
    PropertyPlaceholderAutoConfiguration.class,
    ThymeleafAutoConfiguration.class,
    WebMvcAutoConfiguration.class,
    WebSocketAutoConfiguration.class,
})
public class App {