01@spring_boot使用

Spring Boot 优点

1. 轻量化
2. 提供 Spring 框架各种默认配置来简化项目配置
3. 内嵌 Web 容器
4. 没有冗余代码生成和XML配置要求

Maven 导包

• spring-boot-starter：核心模块，包括了自动配置支持、日志和YAML
• spring-boot-starter-test：测试模块，包括JUnit、Hamcrest、Mockito
• spring-boot-starter-web：Web模块

Spring Boot 项目基本由主加载类、逻辑实现类、单元测试类、以及资源配置文件组成。

一、资源配置文件

1）Maven项目依赖中引入spring-boot-starter-web，在pom.xml中导入相应的依赖包

<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.baron</groupId>
  <artifactId>springboot_person</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <name>springboot</name>
  <description>springboot的maven工程</description>
  
   <!-- Inherit defaults from Spring Boot 继承默认配置-->  
    <parent>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-parent</artifactId>  
        <version>1.4.0.BUILD-SNAPSHOT</version>  
    </parent>  
  
    <!-- Add typical dependencies for a web application 为Web应用程序添加典型的依赖项-->  
    <dependencies>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-web</artifactId>  
        </dependency>  
    </dependencies>  
  
    <!-- Package as an executable jar 打包成可执行的jar包-->  
    <build>  
        <plugins>  
            <plugin>  
                <groupId>org.springframework.boot</groupId>  
                <artifactId>spring-boot-maven-plugin</artifactId>  
            </plugin>  
        </plugins>  
    </build>  
  
    <!-- Add Spring repositories 添加spring的依赖库-->  
    <!-- (you don't need this if you are using a .RELEASE version) 如果你使用的是修订版本，就不需要添加这个-->  
    <repositories>  
        <repository>  
            <id>spring-snapshots</id>  
            <url>http://repo.spring.io/snapshot</url>  
            <snapshots><enabled>true</enabled></snapshots>  
        </repository>  
        <repository>  
            <id>spring-milestones</id>  
            <url>http://repo.spring.io/milestone</url>  
        </repository>  
    </repositories>  
    <pluginRepositories>  
        <pluginRepository>  
            <id>spring-snapshots</id>  
            <url>http://repo.spring.io/snapshot</url>  
        </pluginRepository>  
        <pluginRepository>  
            <id>spring-milestones</id>  
            <url>http://repo.spring.io/milestone</url>  
        </pluginRepository>  
    </pluginRepositories>  
</project>

2）框架资源的配置

在src/main/resources下可以创建application.properties文件，将服务器端口写入

server.port=8081

二、创建主加载类 Application.java

主加载类是springboot最重要的一个类，是启动程序的入口。

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

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

三、创建逻辑实现类 controller

逻辑实现类就是controller层，是服务接口。

• @RequestMapping
  – 定义处：提供初步的请求映射信息。相对于 WEB 应用的根目录
  – 方法处：提供进一步的细分映射信息。相对于类定义处的 URL。若
  类定义处未标注 @RequestMapping，则方法处标记的 URL 相对于
  WEB 应用的根目录.

  • DispatcherServlet 截获请求后，就通过控制器上
  • @RequestMapping 提供的映射信息确定请求所对应的处理方法。
  • @RequestMapping 除了可以使用请求 URL 映射请求外，还可以使用请求方法、请求参数及请求头映射请求

• @PathVariable 可以将 URL 中占位符参数绑定到控制器处理方法的入参中：URL 中的 {xxx} 占位符可以通过@PathVariable("xxx") 绑定到操作方法的入参中。

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class Springweb {
    @RequestMapping("/")
    public String home() {
        return "hello world!";
    }

    @RequestMapping("hello/{name}")
    public String index(@PathVariable String name) {
        return "Hello, " + name;
    }
}

四、程序run运行

.__           .__  .__                ___.                               
|  |__   ____ |  | |  |   ____        \_ |__ _____ _______  ____   ____  
|  |  \_/ __ \|  | |  |  /  _ \        | __ \\__  \\_  __ \/  _ \ /    \ 
|   Y  \  ___/|  |_|  |_(  <_> )       | \_\ \/ __ \|  | \(  <_> )   |  \
|___|  /\___  >____/____/\____/   /\   |___  (____  /__|   \____/|___|  /
     \/     \/                    )/       \/     \/                  \/ 
2017-12-21 13:54:39.527  INFO 11188 --- [           main] com.baron.Application                    : Starting Application on PC-201710141743 with PID 11188 (E:\workspace\springboot_person\target\classes started by Administrator in E:\workspace\springboot_person)
2017-12-21 13:54:39.531  INFO 11188 --- [           main] com.baron.Application                    : No active profile set, falling back to default profiles: default
2017-12-21 13:54:39.605  INFO 11188 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@125dc0f: startup date [Thu Dec 21 13:54:39 CST 2017]; root of context hierarchy
2017-12-21 13:54:41.384  INFO 11188 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-12-21 13:54:41.400  INFO 11188 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2017-12-21 13:54:41.401  INFO 11188 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.4
2017-12-21 13:54:41.504  INFO 11188 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-12-21 13:54:41.504  INFO 11188 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1902 ms
2017-12-21 13:54:41.666  INFO 11188 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-12-21 13:54:41.673  INFO 11188 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-12-21 13:54:41.673  INFO 11188 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-12-21 13:54:41.674  INFO 11188 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-12-21 13:54:41.674  INFO 11188 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-12-21 13:54:42.004  INFO 11188 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@125dc0f: startup date [Thu Dec 21 13:54:39 CST 2017]; root of context hierarchy
2017-12-21 13:54:42.071  INFO 11188 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello/{name}]}" onto public java.lang.String com.baron.web.Springweb.index(java.lang.String)
2017-12-21 13:54:42.072  INFO 11188 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String com.baron.web.Springweb.home()
2017-12-21 13:54:42.075  INFO 11188 --- [           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)
2017-12-21 13:54:42.076  INFO 11188 --- [           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)
2017-12-21 13:54:42.112  INFO 11188 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-21 13:54:42.112  INFO 11188 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-21 13:54:42.152  INFO 11188 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-12-21 13:54:42.286  INFO 11188 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-12-21 13:54:42.346  INFO 11188 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-12-21 13:54:42.350  INFO 11188 --- [           main] com.baron.Application                    : Started Application in 3.35 seconds (JVM running for 3.769)

五、控制面板显示

在src/main/resources下创建banner.txt文件，里面填写显示的内容。

image.png
image.png

六、页面展示

image.png image.png