SpringBoot学习笔记：Getting Started构建第一个Spring Boot工程

摘要：本文参考官方文档部分特定版本如版本官方文档地址注本文基于构建话说在上已经有多颗星了，足见火爆程度简介以下介绍引自创建独立的应用程序直接嵌入，或无需部署文件提供自己的入门来简化你的配置尽可能自动配置提供生产就绪功能，如指标，运行

本文参考 Spring Boot官方文档 Part II. Getting Started部分
特定版本如1.5.10.RELEASE版本官方文档地址：
https://docs.spring.io/spring...
注：本文基于Spring Boot 1.5.10.RELEASE构建

The Spring Boot repository has also a bunch of samples you can run.（话说spring-boot在github上已经有23000多颗星了，足见spring-boot火爆程度）

以下介绍引自 https://projects.spring.io/sp...

Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run". We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.

Features

Create stand-alone Spring applications
创建独立的Spring应用程序

Embed Tomcat, Jetty or Undertow directly (no need to deploy WAR files)
直接嵌入Tomcat，Jetty或Undertow（无需部署WAR文件）

Provide opinionated "starter" POMs to simplify your Maven
configuration
提供自己的"入门"POM来简化你的Maven配置

Automatically configure Spring whenever possible
尽可能自动配置Spring

Provide production-ready features such as metrics, health checks and
externalized configuration
提供生产就绪功能，如指标，运行状况检查和外部配置

Absolutely no code generation and no requirement for XML
configuration
绝对不会生成代码，并且不需要XML配置

Spring Boot 1.5.10.RELEASE版本需要

Java 7 and Spring Framework 4.3.14.RELEASE or above 最好java8及以上
构建工具：Maven (3.2+), and Gradle 2 (2.9 or later) and 3.

Servlet容器：

这里笔者采用构建Empty Project作为Spring Boot学习过程的总工程，以添加Module的方式构建不同学习过程如springboot-first-app、springboot-redis等

在Idea欢迎页点击Create New Project或File --> New Project，弹出以下界面并选择Empty Project

点击Next，填写Project name如SpringBootLearning

点击Finish完成创建，进入工程Idea会弹出Project Structure窗口，可以点击绿色的+按钮来New Module

也可以通过File --> New --> Module

以上构建空工程的步骤只是笔者为了自身的系统学习，读者可以直接创建一个Spring Boot工程
方法一：在 Spring Boot官方Initializer页面 在线构建工程再导入到Ide中

方法二：直接在Idea中Create New Project --> Spring Initializr --> 填写group、artifact -->钩上web --> 点下一步就行了，具体步骤参照笔者New Module步骤即可

    4.0.0

    cn.fulgens.springbootlearning
    springboot-first-app-maven
    0.0.1-SNAPSHOT
    jar

    springboot-first-app-maven
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        1.5.10.RELEASE
         
    

    
        UTF-8
        UTF-8
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

package cn.fulgens.springbootlearning.springbootfirstappmaven.web;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

    @RequestMapping("/")
    public String hello() {
        return "Hello Spring Boot!";
    }

}

方法一：直接运行SpringbootFirstAppMavenApplication中的main方法

package cn.fulgens.springbootlearning.springbootfirstappmaven;

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

@SpringBootApplication
public class SpringbootFirstAppMavenApplication {

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

启动后在浏览器输入localhost:8080

方法二：maven命令启动
cd到项目主目录后执行（其中-Dtest.skip=true表示跳过单元测试）

mvn clean package 
mvn spring-boot:run -Dtest.skip=true

如果是Gradle构建可执行
gradle build
gradle bootRun

方法三：以java -jar的方式启动
maven打包完成后cd到target目录下执行，jar包名称视自己情况而定

java -jar springboot-first-app-maven-0.0.1-SNAPSHOT.jar

package cn.fulgens.springbootlearning.springbootfirstappmaven;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.HttpMethod;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class HelloControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void helloControllerTest() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.request(HttpMethod.GET, "/"))
                .andExpect(MockMvcResultMatchers.status().isOk())
                .andExpect(MockMvcResultMatchers.content().string("Hello Spring Boot!"));
    }

}

spring boot 1.4.0 版本之前使用以下三个注解，参考Spring Boot 系列（二）单元测试&网络请求
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = DemoApplication.class) //在spring boot 1.4.0 版本之后取消了 //classes需要指定spring boot 的启动类如：DemoApplication.class 不然WebApplicationContext不被实例化
@WebAppConfiguration