springBoot 入门（一）—— 使用idea创建第一个springBoot项目

MickyInvQ

发布于 2020-09-27 17:07:53

7300

发布于 2020-09-27 17:07:53

文章被收录于专栏：InvQ的专栏InvQ的专栏

版本使用说明

idea 为 Idea 2017 jdk 采用1.8 maven 采用 3.5.3

创建项目

配置pom依赖的包，然后更新依赖包，pom.xml内容如下：

<?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.wq</groupId>
    <artifactId>beauty</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.0.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-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

一般刚写了pom.xml会出现如下报错

其中, spring-boot-starter-web是支持web的模块, spring-boot-starter-test是支持测试的模块.

这时候需要配置 idea 的 maven 配置

等待引用后，之后就不会报错

配置resources下面的Web资源文件，这里我就配置两个文件，一个是用来存放静态文件夹的static文件，还有一个就是用来存放HTML的资源文件夹templates。这里需要特别主要的是：static文件中一般存放css，js，image等静态资源文件，而templates文件中一般存放各种HTML文件。而且这两个文件都是默认存在的，路径不需要特别的配置就可以直接引用了。aplication.properties是个配置文件，这里面可以配置SpringBoot的相关信息。大家需要注意的是这个文件名千万不要写错，也不要放错位置，不然都不会生效的。书写springBoot入口函数和springMVC控制器测试

DemoApplication.java

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

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

HelloController.java 如果使用@RestController表示里边的方法都以json格式输出, 无需再添加额外的json配置，此时此处并没有使用。

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HelloController {
    @RequestMapping("/index")
    public String index(){
        return "welcome";
    }
}

csstest.css

body {
    padding: 0px;
    margin: auto;
    font-family: "黑体", "仿宋", Arial, "Arial Unicode MS", System;
    background-color: #00F;
    font-size: 20px;
    text-align: left;
}

welcome.html

<html>
<head>
    <title>Title</title>
</head>
<link href="css/csstest.css" rel="stylesheet"/>
<body>
<p>welcome page is login.........</p>
</body>
</html>

application.properties

#修改tomcat的默认的端口号，将8080改为8888
server.port=8888

在DemoApplication页面右击然后run。

注意这个运行时不是用的tomcat，而是直接用的application，(使用的是其内嵌默认的tomcat，而不是我配置的 )

看到如下日志，说明快成功了

然而，有没有看到

** WARNING ** : Your ApplicationContext is unlikely to start due to a @ComponentScan of the default package.

你不太可能成功，因为没有默认包！新建默认包，后如下

再次启动，看到如下，则说明你的 spring boot hello world 已经成功

D:\jdk1.8\bin\java "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2017.2.6\lib\idea_rt.jar=62993:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2017.2.6\bin" -Dfile.encoding=UTF-8 -classpath D:\jdk1.8\jre\lib\charsets.jar;D:\jdk1.8\jre\lib\deploy.jar;D:\jdk1.8\jre\lib\ext\access-bridge-64.jar;D:\jdk1.8\jre\lib\ext\cldrdata.jar;D:\jdk1.8\jre\lib\ext\dnsns.jar;D:\jdk1.8\jre\lib\ext\jaccess.jar;D:\jdk1.8\jre\lib\ext\jfxrt.jar;D:\jdk1.8\jre\lib\ext\localedata.jar;D:\jdk1.8\jre\lib\ext\nashorn.jar;D:\jdk1.8\jre\lib\ext\sunec.jar;D:\jdk1.8\jre\lib\ext\sunjce_provider.jar;D:\jdk1.8\jre\lib\ext\sunmscapi.jar;D:\jdk1.8\jre\lib\ext\sunpkcs11.jar;D:\jdk1.8\jre\lib\ext\zipfs.jar;D:\jdk1.8\jre\lib\javaws.jar;D:\jdk1.8\jre\lib\jce.jar;D:\jdk1.8\jre\lib\jfr.jar;D:\jdk1.8\jre\lib\jfxswt.jar;D:\jdk1.8\jre\lib\jsse.jar;D:\jdk1.8\jre\lib\management-agent.jar;D:\jdk1.8\jre\lib\plugin.jar;D:\jdk1.8\jre\lib\resources.jar;D:\jdk1.8\jre\lib\rt.jar;D:\Users\zhangqi975\workspace\beauty\target\classes;D:\maven\local\repo\org\springframework\boot\spring-boot-starter-web\1.4.0.RELEASE\spring-boot-starter-web-1.4.0.RELEASE.jar;D:\maven\local\repo\org\springframework\boot\spring-boot-starter\1.4.0.RELEASE\spring-boot-starter-1.4.0.RELEASE.jar;D:\maven\local\repo\org\springframework\boot\spring-boot\1.4.0.RELEASE\spring-boot-1.4.0.RELEASE.jar;D:\maven\local\repo\org\springframework\boot\spring-boot-autoconfigure\1.4.0.RELEASE\spring-boot-autoconfigure-1.4.0.RELEASE.jar;D:\maven\local\repo\org\springframework\boot\spring-boot-starter-logging\1.4.0.RELEASE\spring-boot-starter-logging-1.4.0.RELEASE.jar;D:\maven\local\repo\ch\qos\logback\logback-classic\1.1.7\logback-classic-1.1.7.jar;D:\maven\local\repo\ch\qos\logback\logback-core\1.1.7\logback-core-1.1.7.jar;D:\maven\local\repo\org\slf4j\jcl-over-slf4j\1.7.21\jcl-over-slf4j-1.7.21.jar;D:\maven\local\repo\org\slf4j\jul-to-slf4j\1.7.21\jul-to-slf4j-1.7.21.jar;D:\maven\local\repo\org\slf4j\log4j-over-slf4j\1.7.21\log4j-over-slf4j-1.7.21.jar;D:\maven\local\repo\org\yaml\snakeyaml\1.17\snakeyaml-1.17.jar;D:\maven\local\repo\org\springframework\boot\spring-boot-starter-tomcat\1.4.0.RELEASE\spring-boot-starter-tomcat-1.4.0.RELEASE.jar;D:\maven\local\repo\org\apache\tomcat\embed\tomcat-embed-core\8.5.4\tomcat-embed-core-8.5.4.jar;D:\maven\local\repo\org\apache\tomcat\embed\tomcat-embed-el\8.5.4\tomcat-embed-el-8.5.4.jar;D:\maven\local\repo\org\apache\tomcat\embed\tomcat-embed-websocket\8.5.4\tomcat-embed-websocket-8.5.4.jar;D:\maven\local\repo\org\hibernate\hibernate-validator\5.2.4.Final\hibernate-validator-5.2.4.Final.jar;D:\maven\local\repo\javax\validation\validation-api\1.1.0.Final\validation-api-1.1.0.Final.jar;D:\maven\local\repo\org\jboss\logging\jboss-logging\3.3.0.Final\jboss-logging-3.3.0.Final.jar;D:\maven\local\repo\com\fasterxml\classmate\1.3.1\classmate-1.3.1.jar;D:\maven\local\repo\com\fasterxml\jackson\core\jackson-databind\2.8.1\jackson-databind-2.8.1.jar;D:\maven\local\repo\com\fasterxml\jackson\core\jackson-annotations\2.8.1\jackson-annotations-2.8.1.jar;D:\maven\local\repo\com\fasterxml\jackson\core\jackson-core\2.8.1\jackson-core-2.8.1.jar;D:\maven\local\repo\org\springframework\spring-web\4.3.2.RELEASE\spring-web-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\spring-aop\4.3.2.RELEASE\spring-aop-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\spring-beans\4.3.2.RELEASE\spring-beans-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\spring-context\4.3.2.RELEASE\spring-context-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\spring-webmvc\4.3.2.RELEASE\spring-webmvc-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\spring-expression\4.3.2.RELEASE\spring-expression-4.3.2.RELEASE.jar;D:\maven\local\repo\org\slf4j\slf4j-api\1.7.21\slf4j-api-1.7.21.jar;D:\maven\local\repo\org\springframework\spring-core\4.3.2.RELEASE\spring-core-4.3.2.RELEASE.jar;D:\maven\local\repo\org\springframework\boot\spring-boot-starter-thymeleaf\1.4.0.RELEASE\spring-boot-starter-thymeleaf-1.4.0.RELEASE.jar;D:\maven\local\repo\org\thymeleaf\thymeleaf-spring4\2.1.5.RELEASE\thymeleaf-spring4-2.1.5.RELEASE.jar;D:\maven\local\repo\org\thymeleaf\thymeleaf\2.1.5.RELEASE\thymeleaf-2.1.5.RELEASE.jar;D:\maven\local\repo\ognl\ognl\3.0.8\ognl-3.0.8.jar;D:\maven\local\repo\org\javassist\javassist\3.20.0-GA\javassist-3.20.0-GA.jar;D:\maven\local\repo\org\unbescape\unbescape\1.1.0.RELEASE\unbescape-1.1.0.RELEASE.jar;D:\maven\local\repo\nz\net\ultraq\thymeleaf\thymeleaf-layout-dialect\1.4.0\thymeleaf-layout-dialect-1.4.0.jar;D:\maven\local\repo\org\codehaus\groovy\groovy\2.4.7\groovy-2.4.7.jar HelloWord.DemoApplication

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.4.0.RELEASE)

2018-04-11 18:11:08.824  INFO 8904 --- [           main] HelloWord.DemoApplication                : Starting DemoApplication on IQSZ-L3025 with PID 8904 (D:\Users\zhangqi975\workspace\beauty\target\classes started by ZHANGQI975 in D:\Users\zhangqi975\workspace\beauty)
2018-04-11 18:11:08.828  INFO 8904 --- [           main] HelloWord.DemoApplication                : No active profile set, falling back to default profiles: default
2018-04-11 18:11:09.840  INFO 8904 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3f197a46: startup date [Wed Apr 11 18:11:09 CST 2018]; root of context hierarchy
2018-04-11 18:11:15.126  INFO 8904 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8888 (http)
2018-04-11 18:11:15.155  INFO 8904 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2018-04-11 18:11:15.157  INFO 8904 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.4
2018-04-11 18:11:15.431  INFO 8904 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2018-04-11 18:11:15.431  INFO 8904 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 5596 ms
2018-04-11 18:11:15.751  INFO 8904 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2018-04-11 18:11:15.763  INFO 8904 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-04-11 18:11:15.763  INFO 8904 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-04-11 18:11:15.764  INFO 8904 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-04-11 18:11:15.764  INFO 8904 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-04-11 18:11:16.335  INFO 8904 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3f197a46: startup date [Wed Apr 11 18:11:09 CST 2018]; root of context hierarchy
2018-04-11 18:11:16.464  INFO 8904 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/index]}" onto public java.lang.String HelloWord.HelloController.index()
2018-04-11 18:11:16.470  INFO 8904 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2018-04-11 18:11:16.470  INFO 8904 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2018-04-11 18:11:16.517  INFO 8904 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-04-11 18:11:16.517  INFO 8904 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-04-11 18:11:16.596  INFO 8904 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-04-11 18:11:17.792  INFO 8904 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2018-04-11 18:11:18.593  INFO 8904 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8888 (http)
2018-04-11 18:11:18.600  INFO 8904 --- [           main] HelloWord.DemoApplication                : Started DemoApplication in 10.957 seconds (JVM running for 12.28)

打开浏览器，输入： http://localhost:8888/index 出现

则说明成功。为了证明spring boot 的热部署性，更改DemoApplication.java文件为

package HelloWord;

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

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
        System.out.println("spring boot 启动成功！");
    }
}

如果再次启动时候，没有停止，那么会报错如下

停止后，再次启动，查看日志：

关于停止spring boot 内部的Tomcat 有两种方式

第一种：借用idea功能

第二种，优雅的方式

Maven 增加依赖

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

配置文件application.properties配置启用shutdown的HTTP访问

　#启用 shutdown endpoint的HTTP访问 endpoints.shutdown.enabled=true #不需要用户名密码验证 endpoints.shutdown.sensitive=false 此时，配置文件如下：

#修改tomcat的默认的端口号，将8080改为8888
server.port=8888

#启用shutdown endpoint的HTTP访问
endpoints.shutdown.enabled=true 

#不需要用户名密码验证
endpoints.shutdown.sensitive=false

　POST请求到shutdown路径以上配置完成后，可以使用curl -X POST localhost:port/shutdown发动post请求，即可优雅的停止应用。如果使用Linux：

curl -X POST localhost:8888/manage/shutdown
 {"message":"Shutting down, bye..."}

如果使用Windows 则直接在浏览器中输入

http://localhost:8888/shutdown

但是报错，

因为这个是以post请求有效的。 Get请求不支持后台也同样报错

所以，这条路走不通了（暂时走不通，将来如果发现，或者聪明的你知道，请留言）

至此，spring boot 版本的Hello world 完毕！

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