SpringBoot學習(四)-->SpringBoot快速入門,開山篇

Spring Boot簡介

Spring Boot的目的在於創建和啟動新的基於Spring框架的項目。Spring Boot會選擇最適合的Spring子項目和第三方開源庫進行整合。大部分Spring Boot應用只需要非常少的配置就可以快速運行起來

Spring Boot是伴隨着Spring4.0誕生的，旨在簡化開發。
Spring Boot提供了一種快速使用Spring的方式

SpringBoot官方文檔：http://spring.io/projects/spring-boot

>>Spring Boot特點

1：為基於Spring的開發提供更快的入門體驗
2：創建可以獨立運行的Spring應用
3：直接嵌入Tomcat或Jetty服務器，不需要打包成WAR文件
4：提供推薦的基礎POM文件（starter）來簡化Apache Maven配置
5：盡可能的根據項目依賴來自動配置Spring框架
6：Spring Boot使編碼、配置、部署、監控變簡單
7：提供可以直接在生產環境中使用的功能，如性能指標、應用信息和應用健康檢查
8：開箱即用，沒有代碼生成，也無需XML配置。同時也可以修改默認值來滿足特定的需求
9：其他大量的項目都是基於Spring Boot之上的，如Spring Cloud

>>Spring Boot缺點

1：依賴太多，隨便的一個Spring Boot應用都有好幾十M
2：缺少服務的注冊和發現等解決方案
3：缺少監控集成方案、安全管理方案
4：中文的文檔和資料太少且不夠深入

>>Spring Boot應用場景

1：Spring能夠應用的場景
2：java web應用
3：微服務

 

寫個示例：Hello SpringBoot

1、創建Maven工程

工程結構如下：

2、配置pom.xml文件

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mmzs</groupId>
    <artifactId>springBoot00</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>springBoot00 Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <!-- 一定要有spring-boot-starter-parent,其中包含了spring的各種插件版本號 -->
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
        <relativePath /><!-- lookup parent from repository -->
    </parent>

    <!-- 父類統一管理版本信息 -->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <!-- springboot 默認java版本是1.6,這里顯示給它指定為1.7 -->
        <java.version>1.7</java.version>
    </properties>

    <dependencies>
        <dependency>
            <!-- 導入spring boot的web支持,可以不寫版本號,在spring-boot-starter-parent已經包含 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>


    <build>
        <finalName>spring_boot</finalName>
        <!-- 添加Spring boot的maven插件,可以不寫版本號,在spring-boot-starter-parent已經包含  -->
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>

    </build>
</project>
 

3、編寫代碼

package com.mmzs.springboot;
 
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
/**
 * Created by mmzs 2018年4月2日 11:50:57
 * springboot注解詳解：http://www.cnblogs.com/mmzs/p/8874349.html
 */
//用於標注控制層組件(如struts中的action)，@ResponseBody和@Controller的合集，
//這樣子獲取的數據返回前台時也會自動轉發為json格式。 
@RestController
//Spring Boot自動配置（auto-configuration）：嘗試根據你添加的jar依賴自動配置你的Spring應用。
@EnableAutoConfiguration
public class HelloController {
 
    @RequestMapping("/hello")
    @ResponseBody //會使用詳細轉換器輸出結果
    public String hello() {
        return "Hello Spring-Boot";
    }
 
    @RequestMapping("/info")
    public Map<String, String> getInfo(@RequestParam String name) {
        Map<String, String> map = new HashMap<>();
        map.put("name", name);
        return map;
    }
 
    @RequestMapping("/list")
    public List<Map<String, String>> getList() {
        List<Map<String, String>> list = new ArrayList<>();
        Map<String, String> map = null;
        for (int i = 1; i <= 5; i++) {
            map = new HashMap<>();
            map.put("name", "mmzs+" + i);
            list.add(map);
        }
        return list;
    }
}
 

package com.mmzs.springboot;

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

/**
 * Created by mmzs 2018年4月2日 11:48:38
 * springboot注解詳解：http://www.cnblogs.com/mmzs/p/8874349.html
 */
//Spring Boot項目的核心注解，主要目的是開啟自動配置。
//包含了@ComponentScan、@Configuration和@EnableAutoConfiguration注解。
//其中@ComponentScan默認掃描@SpringBootApplication所在類的同級目錄以及它的子目錄。
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}
 

4、測試效果

運行Application類，結果如下：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.2.RELEASE)

2018-07-02 12:17:03.434  INFO 5988 --- [           main] com.mmzs.springboot.Application          : Starting Application on CVHOPASEHFXPHFV with PID 5988 (D:\Project\springBoot00\target\classes started by Administrator in D:\Project\springBoot00)
2018-07-02 12:17:03.442  INFO 5988 --- [           main] com.mmzs.springboot.Application          : No active profile set, falling back to default profiles: default
2018-07-02 12:17:03.562  INFO 5988 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@27fe3806: startup date [Mon Jul 02 12:17:03 CST 2018]; root of context hierarchy
2018-07-02 12:17:06.724  INFO 5988 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2018-07-02 12:17:06.751  INFO 5988 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2018-07-02 12:17:06.753  INFO 5988 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.11
2018-07-02 12:17:06.971  INFO 5988 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2018-07-02 12:17:06.972  INFO 5988 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 3415 ms
2018-07-02 12:17:07.260  INFO 5988 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2018-07-02 12:17:07.266  INFO 5988 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-07-02 12:17:07.267  INFO 5988 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-07-02 12:17:07.267  INFO 5988 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-07-02 12:17:07.267  INFO 5988 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-07-02 12:17:07.788  INFO 5988 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@27fe3806: startup date [Mon Jul 02 12:17:03 CST 2018]; root of context hierarchy
2018-07-02 12:17:07.928  INFO 5988 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/list]}" onto public java.util.List<java.util.Map<java.lang.String, java.lang.String>> com.mmzs.springboot.HelloController.getList()
2018-07-02 12:17:07.929  INFO 5988 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello]}" onto public java.lang.String com.mmzs.springboot.HelloController.hello()
2018-07-02 12:17:07.931  INFO 5988 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/info]}" onto public java.util.Map<java.lang.String, java.lang.String> com.mmzs.springboot.HelloController.getInfo(java.lang.String)
2018-07-02 12:17:07.936  INFO 5988 --- [           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)
2018-07-02 12:17:07.937  INFO 5988 --- [           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)
2018-07-02 12:17:08.012  INFO 5988 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-07-02 12:17:08.013  INFO 5988 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-07-02 12:17:08.103  INFO 5988 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-07-02 12:17:08.403  INFO 5988 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2018-07-02 12:17:08.531  INFO 5988 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-07-02 12:17:08.538  INFO 5988 --- [           main] com.mmzs.springboot.Application          : Started Application in 5.736 seconds (JVM running for 6.592)

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