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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