二SpringBoot2核心技术——SpringBoot入门

Posted 2021-06-01 上善若水

一、SpringBoot2入门

1.1、环境要求

• Java8 & 兼容Java14
• Maven 3.3+
  

1.1.1、 mavn配置

<mirrors>
  <mirror>
	<id>nexus-aliyun</id>
	<mirrorOf>central</mirrorOf>
	<name>Nexus aliyun</name>
	<url>http://maven.aliyun.com/nexus/content/groups/public</url>
  </mirror>
</mirrors>
 
<profiles>
	<profile>
	  <id>jdk-1.8</id>
	  <activation>
		<activeByDefault>true</activeByDefault>
		<jdk>1.8</jdk>
	  </activation>
	  <properties>
		<maven.compiler.source>1.8</maven.compiler.source>
		<maven.compiler.target>1.8</maven.compiler.target>
		<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
	  </properties>
	</profile>
</profiles>

1.2、HelloWorld

1.2.1、创建maven工程

1.2.2、引入依赖

参考官网文档：https://docs.spring.io/spring-boot/docs/current/reference/html/getting-started.html

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.0</version>
    </parent>

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

1.2.3、创建主程序

package com.xbmu;

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

/**
 * 主程序类
 * @SpringBootApplication : 这是一个SpringBoot应用
 */
@SpringBootApplication
public class MainApplication {
    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class,args);
    }
}

1.2.4、编写业务

package com.xbmu.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
//@Controller
//@ResponseBody
@RestController
public class HelloController {
    @RequestMapping("/hello")
    public String sayHello()
    {
        return "Hello,Spring Boot2 !";
    }
}

@RestController 源码

@Controller
@ResponseBody
等价于
@RestController

1.2.5、测试

直接运行main方法，MainApplication.java类中的main方法

1.2.6、简化配置

参考官网文档：https://docs.spring.io/spring-boot/docs/current/reference/html/application-properties.html#application-properties

创建文件：application.properties
src/main/resources/application.properties

server.port=8888

1.2.7、简化部署

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

把项目打成jar包，直接在目标服务器质性即可。


注意：取消掉cmd的快速编辑模式