关于SpringBoot的初识

关于SpringBoot的初识
SpringBoot简化了原先使用ssm框架开发代码的繁琐的文件配置操作，它使用起来更加方便，也就是极简的配置来省略以前的配置文件的操作

首先需要一个启动引导类，并且添加@SpringBootApplication注解

package com.itheima;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Springboot03ConfigApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot03ConfigApplication.class, args);
    }

}

在pom.xml文件中的配置，需要导入SpringBoot的坐标，以及web的坐标省去了手动导jar包的烦恼

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.itheima</groupId>
    <artifactId>springboot03-config</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot03-config</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!--
            处理@ConfigurationProperties注解导入配置的处理器
        -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </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>

测试类

package com.itheima.controller;

import com.itheima.pojo.Person;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/*
 *  向浏览器输出一个字符串：Hi,my name is SpringBoot
 * */
@RestController
public class HelloController {

    @Value("${message1}")
    private String message1;
    @Value("${message2}")
    private String message2;

    @Autowired
    private Person person;

    @Autowired
    private Environment environment;

    @RequestMapping("sayHello")
    public String sayHello() {
//        System.out.println("message1:"+message1);
//        System.out.println("message2:"+message2);
        System.out.println("Person:"+person);
        System.out.println("message1:"+environment.getProperty("message1"));
        System.out.println("message2:"+environment.getProperty("message2"));
//        return "Hi.my name is SpringBoot!!! message1:"+message1+",message2:"+message2;
        return "Hi.my name is SpringBoot!!! Person:"+person;
    }
}