一、SpringBoot基础

学习SpringCloud之前，需要对Maven以及SpringBoot有一定的了解，运用JDK1.8及以上。

1 建立一个Maven的项目，目录结构参考如下：

image.png

2 pom文件：

<?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.lyc.spring.cloud</groupId>
    <artifactId>springCloud1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>spring-cloud-one</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.8.RELEASE</version>
        <relativePath/>
    </parent>

    <properties>
        <project.build.sourceEnncoding>UTF-8</project.build.sourceEnncoding>
        <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-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>

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

3 properties脚本

在项目的resources目录中可以看到是三个，运行时加载的是第一个。application.properties：

spring.profiles.active=dev

意为加载application.properties时，application-dev.properties生效，具体原理自行查看springBoot的profiles配置。application-dev.properties的代码如下：

server.port=1111
spring.application.name=hello
debug=true

# 默认只公开了/health和/info端点，要想暴露所有端点只需设置成星号即可
management.endpoints.web.exposure.include=*
# 显式启用/shutdown端点
management.endpoint.shutdown.enabled=true
# 要公开所有（已启用）网络端点除env端点之外
management.endpoints.web.exposure.exclude=env
# 设置管理服务的上下文路径，默认值为 “”
management.server.servlet.context-path=
# 设置管理服务的端口
management.server.port=
# 设置管理端点的基本路径，默认值为：actuator
management.endpoints.web.base-path

如上图所示，开通了debug模式，同时将系统性能管理的actuator模块儿也加再进来了

4 启动类

HelloApplication.java代码：

package com.lyc.spring;

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

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

5 对应的Controller里HelloController代码如下：

package com.lyc.spring.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String index(){
        return "Hello World!";
    }

6 在IDE里直接Run这个启动类，浏览器中查看：http://localhost:1111/hello即可看到浏览器里出现了Hello World的字样: