Java web开发--springboot
Java有很多web框架
但是有的框架不是很好用:比如Java Servlets(个人感觉)不好调试,WEB-INF文件关联来关联去很烦躁,启动后 crtl+c还关闭不了(我一般习惯用ctrl+c命令来关闭服务).导致后面我调试springboot时一直报错,原来是Java Servlets的服务没关(我习惯性ctrl+c没关掉,也没提示),端口占用的问题
介绍spring boot的使用
我介绍我使用的vscode的wsl Linux子环境比较简单的方法
像去网站上填参数然后下载一个压缩包解压对新手来说太不友好,我参数都看不懂什么意思
新建项目springboot
我直接使用maven命令构建一个新spring boot项目
mvn archetype:generate -DgroupId=com.example -DartifactId=demo -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false
其中的-DgroupId=com.example -DartifactId=demo根据自己的需要填写
配置pom.xml
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.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>9</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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
编写简单的代码
package com.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
public class App {
public static void main(String[] args) {
SpringApplication.run(App.class, args);
}
}
有些import不需要,包警告的就删掉.
直接调试代码,查看环境是否有问题,一般是不会有什么问题的
返回一般是这样环境就没问题了;如果有报错再自己修复吧
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.0.1.RELEASE)
2023-07-07 17:42:29.412 INFO 32491 --- [ main] com.example.App : Starting App on LAPTOP-MOE7TCNL with PID 32491 (/root/java/springboottest/target/classes started by root in /root/java/springboottest)
2023-07-07 17:42:29.414 INFO 32491 --- [ main] com.example.App : No active profile set, falling back to default profiles: default
2023-07-07 17:42:29.464 INFO 32491 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4562e04d: startup date [Fri Jul 07 17:42:29 CST 2023]; root of context hierarchy
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils$1 (file:/root/.m2/repository/org/springframework/spring-core/5.0.5.RELEASE/spring-core-5.0.5.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2023-07-07 17:42:30.373 INFO 32491 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2023-07-07 17:42:30.406 INFO 32491 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2023-07-07 17:42:30.407 INFO 32491 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.29
2023-07-07 17:42:30.418 INFO 32491 --- [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: [/usr/java/packages/lib:/usr/lib/x86_64-linux-gnu/jni:/lib/x86_64-linux-gnu:/usr/lib/x86_64-linux-gnu:/usr/lib/jni:/lib:/usr/lib]
2023-07-07 17:42:30.506 INFO 32491 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2023-07-07 17:42:30.506 INFO 32491 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1048 ms
2023-07-07 17:42:30.620 INFO 32491 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Servlet dispatcherServlet mapped to [/]
2023-07-07 17:42:30.625 INFO 32491 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2023-07-07 17:42:30.625 INFO 32491 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2023-07-07 17:42:30.625 INFO 32491 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2023-07-07 17:42:30.626 INFO 32491 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2023-07-07 17:42:30.732 INFO 32491 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2023-07-07 17:42:30.958 INFO 32491 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4562e04d: startup date [Fri Jul 07 17:42:29 CST 2023]; root of context hierarchy
2023-07-07 17:42:31.038 INFO 32491 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/index],methods=[GET]}" onto public com.example.App$MyResponse com.example.App.getIndex()
2023-07-07 17:42:31.045 INFO 32491 --- [ 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)
2023-07-07 17:42:31.046 INFO 32491 --- [ 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)
2023-07-07 17:42:31.075 INFO 32491 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2023-07-07 17:42:31.075 INFO 32491 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2023-07-07 17:42:31.233 INFO 32491 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2023-07-07 17:42:31.281 INFO 32491 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2023-07-07 17:42:31.290 INFO 32491 --- [ main] com.example.App : Started App in 2.201 seconds (JVM running for 2.499)
2023-07-07 17:42:40.207 INFO 32491 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet'
2023-07-07 17:42:40.208 INFO 32491 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2023-07-07 17:42:40.222 INFO 32491 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 14 ms
2023-07-08 00:01:14.340 INFO 32491 --- [ Thread-2] ConfigServletWebServerApplicationContext : Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4562e04d: startup date [Fri Jul 07 17:42:29 CST 2023]; root of context hierarchy
2023-07-08 00:01:14.484 INFO 32491 --- [ Thread-2] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
最后再写一个get请求json数据响应看看基本功能
package com.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
public class App {
public static void main(String[] args) {
SpringApplication.run(App.class, args);
}
@GetMapping("/index")
public MyResponse getIndex() {
return new MyResponse(100, "ok", "hello world!");
}
private static class MyResponse {
private int code;
private String msg;
private String data;
public MyResponse(int code, String msg, String data) {
this.code = code;
this.msg = msg;
this.data = data;
}
// Getters and setters
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
}
}
没使用的方法可以删掉
执行结果:
访问http://localhost:8080/index接口
完全没有问题
这样就可以探究其他的东西了,例如请求数据的接受处理,数据库连接,rises等等深度探索
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