一、注解
@SpringBootApplication
点开查看源码是由多个注解合成的注解，其中主要的注解有：
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan
三个关键的注解：
@ComponentScan 自动扫描加载进来的包，-----------可以扫描自动加载的bean
@EnableAutoConfiguration 启动自动配置
@SpringBootConfiguration 继承了@Configuration，所以可以使用@Configuration内容
@Configuration是spring提供的注解，@SpringBootConfiguration是springboot提供的注解。效果几乎一样，用哪个看自己的习惯。
二、pom配置
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 6 <groupId>com.springboot</groupId> 7 <artifactId>quick_start</artifactId> 8 <version>0.0.1-SNAPSHOT</version> 9 <packaging>jar</packaging> 10 11 <name>quick_start</name> 12 <url>http://maven.apache.org</url> 13 <description>Demo project for Spring Boot</description> 14 15 <!--<parent>--> 16 <!--<groupId>org.springframework.boot</groupId>--> 17 <!--<artifactId>spring-boot-starter-parent</artifactId>--> 18 <!--<version>2.0.2.RELEASE</version>--> 19 <!--<relativePath/> <!– lookup parent from repository –>--> 20 <!--</parent>--> 21 22 <properties> 23 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 24 <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 25 <maven.compiler.source>1.8</maven.compiler.source> 26 <maven.compiler.target>1.8</maven.compiler.target> 27 <java.version>1.8</java.version> 28 </properties> 29 30 <dependencies> 31 <!--不使用parent方式进行依赖,需要scope和type设置--> 32 <dependency> 33 <groupId>org.springframework.boot</groupId> 34 <artifactId>spring-boot-dependencies</artifactId> 35 <version>2.0.2.RELEASE</version> 36 <scope>import</scope> 37 <type>pom</type> 38 </dependency> 39 40 41 <dependency> 42 <groupId>org.springframework.boot</groupId> 43 <artifactId>spring-boot-starter-web</artifactId> 44 </dependency> 45 46 <dependency> 47 <groupId>org.springframework.boot</groupId> 48 <artifactId>spring-boot-starter-test</artifactId> 49 <scope>test</scope> 50 </dependency> 51 </dependencies> 52 53 <build> 54 <plugins> 55 <plugin> 56 <groupId>org.springframework.boot</groupId> 57 <artifactId>spring-boot-maven-plugin</artifactId> 58 </plugin> 59 </plugins> 60 </build> 61 62 63 </project>
三、Application调用的三种方法
方法一：静态方法调用
1 package com.springboot;
2
3 import org.springframework.boot.SpringApplication;
4 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
5 import org.springframework.boot.autoconfigure.SpringBootApplication;
6 import org.springframework.context.ConfigurableApplicationContext;
7 import org.springframework.context.annotation.Bean;
8 import org.springframework.context.annotation.ComponentScan;
9
10 /******************************
11 * @Author : liuyang
12 * @ClassName : QuickStartApplication
13 * @Date : 2018 五月 20
14 * @Time : 01:05:59
15 * @Type : SpringBoot
16 * @Version : 1.0
17 * @Return :
18 * @Description :
19 *******************************/
20
21 @ComponentScan
22 @EnableAutoConfiguration
23 public class QuickStartApplication {
24
25 @Bean
26 public Runnable createRunnable() {
27
28 return () -> {
29 System.out.println("Spring Boot is Run");
30 };
31
32 }
33
34 public static void main(String[] args) {
35 ConfigurableApplicationContext applicationContext = SpringApplication.run(QuickStartApplication.class,args);
36 applicationContext.getBean(Runnable.class).run();
37 System.out.println(applicationContext.getBean(User.class));
38 }
39 }
方法二：非态方法调用，可以拥有多个资源入口
1 package com.springboot;
2
3 import com.srpingboot.nostatic.ApplicationDemo;
4 import org.springframework.boot.SpringApplication;
5 import org.springframework.context.ConfigurableApplicationContext;
6
7 import java.util.HashSet;
8 import java.util.Set;
9
10 /**
11 * Created by
12 *
13 * @author: liuya
14 * @Date: 2018/5/20 2:18
15 * @Description: quick_start
16 * <p>
17 * 指定多个源,调用非springApplication方法
18 */
19
20 public class ManyApplication {
21
22 public static void main(String[] args) {
23
24 // new实例对象调用
25 SpringApplication application = new SpringApplication();
26
27 // 可以指定多个源的方式
28 Set<String> sets = new HashSet<>();
29 sets.add(ApplicationDemo.class.getName());
30 sets.add(User.class.getName());
31 application.setSources(sets);
32
33
34
35 ConfigurableApplicationContext applicationContext = application.run(args);
36 applicationContext.getBean(Runnable.class).run();
37 System.out.println(applicationContext.getBean(User.class));
38 }
39
40
41 }
建立ApplicationDemo
1 package com.srpingboot.nostatic;
2
3 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
4 import org.springframework.context.annotation.Bean;
5 import org.springframework.context.annotation.ComponentScan;
6
7 /**
8 * Created by
9 *
10 * @author: liuya
11 * @Date: 2018/5/20 2:23
12 * @Description: quick_start
13 */
14 @ComponentScan
15 @EnableAutoConfiguration
16 public class ApplicationDemo {
17
18 @Bean
19 public Runnable createRunnable() {
20
21 return () -> {
22 System.out.println("Spring Boot is Run");
23 };
24
25 }
26 }
方法三 ：构造函数指定方式
1 package com.springboot;
2
3 import com.srpingboot.nostatic.ApplicationDemo;
4 import org.springframework.boot.SpringApplication;
5 import org.springframework.context.ConfigurableApplicationContext;
6
7 import java.util.HashSet;
8 import java.util.Set;
9
10 /**
11 * Created by
12 *
13 * @author: liuya
14 * @Date: 2018/5/20 2:18
15 * @Description: quick_start
16 * <p>
17 * 指定多个源,调用非springApplication方法
18 */
19
20
21 public class ManyApplication {
22
23 public static void main(String[] args) {
24
25 //构造函数指定方式
26 SpringApplication application = new SpringApplication(ApplicationDemo.class,User.class);
27
28
29
30 ConfigurableApplicationContext applicationContext = application.run(args);
31 applicationContext.getBean(Runnable.class).run();
32 System.out.println(applicationContext.getBean(User.class));
33 }
34
35
36 }
源码地址：
https://github.com/liushaoye/quick_start
原文地址：https://www.cnblogs.com/liuyangfirst/p/9062346.html
时间： 2024-10-09 07:48:49