从 maven 到 springboot
背景
之前做 spring-boot 的项目开发，总是用的 IDEA 中的项目模板；虽然来的快不用去关注细节，高屋建瓴的来讲它就是一个 maven 项目，但是对于怎么从一个空的 maven 项目一步步建设成一个 spring-boot 项目还是不了解。最近刚好知道了一些，在这里记录一下。
第一步 创建一个 maven 项目
1、创建一个空的 spring-boot 项目。
mvn archetype:generate -DgroupId=com.sqlpy -DartifactId=setup-spring-boot -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4 -DinteractiveMode=false
tree setup-spring-boot
setup-spring-boot
├── pom.xml
└── src
├── main
│ └── java
│ └── com
│ └── sqlpy
│ └── App.java
└── test
└── java
└── com
└── sqlpy
└── AppTest.java
2、pom 文件的内容如下。
<?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.sqlpy</groupId>
<artifactId>setup-spring-boot</artifactId>
<version>1.0-SNAPSHOT</version>
<name>setup-spring-boot</name>
<url>https://www.sqlpy.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
第二步 添加依赖
1、添加 spring-boot 的依赖。
<?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.sqlpy</groupId>
<artifactId>setup-spring-boot</artifactId>
<version>1.0-SNAPSHOT</version>
<name>setup-spring-boot</name>
<url>https://www.sqlpy.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
2、这个依赖被添加之后，它会自动加载它的子依赖。
第三步 添加代码
package com.sqlpy;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* Hello world!
*
*/
@RestController
@SpringBootApplication
public class App
{
public static void main( String[] args )
{
SpringApplication.run(App.class);
}
@RequestMapping("/")
public String index() {
return "hello this is sqlpy.com";
}
}
第四步 在 IDEA 中运行
1、在 IDEA 中运行 App.main 函数
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.0.2.RELEASE)
2021-09-04 11:11:14.871 INFO 20886 --- [ main] com.sqlpy.App : Starting App on NEEKYJIANG-MB2 with PID 20886 (/Users/jianglexing/temps/setup-spring-boot/target/classes started by jianglexing in /Users/jianglexing/temps/setup-spring-boot)
2021-09-04 11:11:14.874 INFO 20886 --- [ main] com.sqlpy.App : No active profile set, falling back to default profiles: default
2021-09-04 11:11:14.907 INFO 20886 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@60611244: startup date [Sat Sep 04 11:11:14 CST 2021]; root of context hierarchy
2021-09-04 11:11:15.543 INFO 20886 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-09-04 11:11:15.557 INFO 20886 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-09-04 11:11:15.557 INFO 20886 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.31
2021-09-04 11:11:15.560 INFO 20886 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/Users/jianglexing/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.]
2021-09-04 11:11:15.609 INFO 20886 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-09-04 11:11:15.609 INFO 20886 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 704 ms
2021-09-04 11:11:15.685 INFO 20886 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Servlet dispatcherServlet mapped to [/]
2021-09-04 11:11:15.688 INFO 20886 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2021-09-04 11:11:15.689 INFO 20886 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2021-09-04 11:11:15.689 INFO 20886 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2021-09-04 11:11:15.689 INFO 20886 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2021-09-04 11:11:15.760 INFO 20886 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:11:15.890 INFO 20886 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@60611244: startup date [Sat Sep 04 11:11:14 CST 2021]; root of context hierarchy
2021-09-04 11:11:15.923 INFO 20886 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String com.sqlpy.App.index()
2021-09-04 11:11:15.927 INFO 20886 --- [ 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.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2021-09-04 11:11:15.927 INFO 20886 --- [ 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.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2021-09-04 11:11:15.940 INFO 20886 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:11:15.940 INFO 20886 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:11:16.022 INFO 20886 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2021-09-04 11:11:16.054 INFO 20886 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-09-04 11:11:16.058 INFO 20886 --- [ main] com.sqlpy.App : Started App in 1.496 seconds (JVM running for 2.069)
2、这个时候在浏览器中可以看到如下内容。
解决手工执行时的报错问题
1、刚才我们通过 IDEA 执行是没有问题的，但是有人选择手工执行，那么会遇到这样的一个错误。
mvn spring-boot:run
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.479 s
[INFO] Finished at: 2021-09-04T11:20:30+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] No plugin found for prefix 'spring-boot' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/jianglexing/.m2/repository), central-mirror (http://maven.sqlpy.com:8080/nexus/content/groups/public/)] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/NoPluginFoundForPrefixException
2、从报错信息来看是插件在本地仓库中找不到，这里有一个要记住的地方是，这个插件声明了在 spring-boot-starter-parent 这个 pom 中，所以我们还要加一个 parent。
<?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.sqlpy</groupId>
<artifactId>setup-spring-boot</artifactId>
<version>1.0-SNAPSHOT</version>
<name>setup-spring-boot</name>
<url>https://www.sqlpy.com</url>
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<version>2.0.2.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
3、现在的工执行也没有问题了。
mvn spring-boot:run
[INFO] Scanning for projects...
[INFO]
[INFO] --------------------< com.sqlpy:setup-spring-boot >---------------------
[INFO] Building setup-spring-boot 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] >>> spring-boot-maven-plugin:2.0.2.RELEASE:run (default-cli) > test-compile @ setup-spring-boot >>>
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:resources (default-resources) @ setup-spring-boot ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/jianglexing/temps/setup-spring-boot/src/main/resources
[INFO] skip non existing resourceDirectory /Users/jianglexing/temps/setup-spring-boot/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ setup-spring-boot ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/jianglexing/temps/setup-spring-boot/target/classes
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:testResources (default-testResources) @ setup-spring-boot ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/jianglexing/temps/setup-spring-boot/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.7.0:testCompile (default-testCompile) @ setup-spring-boot ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/jianglexing/temps/setup-spring-boot/target/test-classes
[INFO]
[INFO] <<< spring-boot-maven-plugin:2.0.2.RELEASE:run (default-cli) < test-compile @ setup-spring-boot <<<
[INFO]
[INFO]
[INFO] --- spring-boot-maven-plugin:2.0.2.RELEASE:run (default-cli) @ setup-spring-boot ---
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.0.2.RELEASE)
2021-09-04 11:28:57.520 INFO 22279 --- [ main] com.sqlpy.App : Starting App on NEEKYJIANG-MB2 with PID 22279 (/Users/jianglexing/temps/setup-spring-boot/target/classes started by jianglexing in /Users/jianglexing/temps/setup-spring-boot)
2021-09-04 11:28:57.522 INFO 22279 --- [ main] com.sqlpy.App : No active profile set, falling back to default profiles: default
2021-09-04 11:28:57.559 INFO 22279 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@272de720: startup date [Sat Sep 04 11:28:57 CST 2021]; root of context hierarchy
2021-09-04 11:28:58.277 INFO 22279 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-09-04 11:28:58.297 INFO 22279 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-09-04 11:28:58.297 INFO 22279 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.31
2021-09-04 11:28:58.307 INFO 22279 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/Users/jianglexing/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.]
2021-09-04 11:28:58.369 INFO 22279 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-09-04 11:28:58.369 INFO 22279 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 813 ms
2021-09-04 11:28:58.455 INFO 22279 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Servlet dispatcherServlet mapped to [/]
2021-09-04 11:28:58.459 INFO 22279 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2021-09-04 11:28:58.459 INFO 22279 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2021-09-04 11:28:58.459 INFO 22279 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2021-09-04 11:28:58.459 INFO 22279 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2021-09-04 11:28:58.536 INFO 22279 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:28:58.668 INFO 22279 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@272de720: startup date [Sat Sep 04 11:28:57 CST 2021]; root of context hierarchy
2021-09-04 11:28:58.721 INFO 22279 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String com.sqlpy.App.index()
2021-09-04 11:28:58.724 INFO 22279 --- [ 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.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2021-09-04 11:28:58.725 INFO 22279 --- [ 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.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2021-09-04 11:28:58.741 INFO 22279 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:28:58.742 INFO 22279 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-09-04 11:28:58.856 INFO 22279 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2021-09-04 11:28:58.891 INFO 22279 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-09-04 11:28:58.895 INFO 22279 --- [ main] com.sqlpy.App