IntelliJ IDEA 2017版 SpringBoot的核心配置详解

Spring Boot的核心

  （1）Spring Boot的项目一般都会有*Application的入口类，入口类中会有main方法，这是一个标准的Java应用程序的入口方法。

 （2）@SpringBootApplication注解是Spring Boot的核心注解，它其实是一个组合注解：

  因为@SpringBootApplication注解包含了@Configuration注解的内容，所以

    在Spring Boot项目中推荐使用@ SpringBootConfiguration替代@Configuration
    @ComponentScan：默认扫描@SpringBootApplication所在类的同级目录以及它的子目录。

（3）@EnableAutoConfiguration：启用自动配置，该注解会使Spring Boot根据项目中依赖的jar包自动配置项目的配置项

（4）因继承省略的注解

         

实战例子:

Pom.需要注释

 <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-tomcat</artifactId>
             <!--<scope>provided</scope>-->
         </dependency>

Pom完整版

 <?xml version="1.0" encoding="UTF-8"?>
 <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/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>

     <groupId>com.example</groupId>
     <artifactId>20180401</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>

     <name>20180401three</name>
     <description>Demo project for Spring Boot</description>

     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>2.0.0.RELEASE</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.8</java.version>
     </properties>

     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>

         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-tomcat</artifactId>
             <!--<scope>provided</scope>-->
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>

     <build>
         <plugins>
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
             </plugin>
         </plugins>
     </build>

 </project>

Application

 package com.example.demo;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;

 @Controller
 @SpringBootApplication
 @SpringBootConfiguration
 @EnableAutoConfiguration
 @ComponentScan
 public class Application {

     @RequestMapping("hello")
     @ResponseBody
     public String hello(){
         return "hello world！";
     }

     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
 }

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