Spring Boot 笔记1(启动类与控制器)

采用Spring Tool Suit 4
java jdk 17
学习启动类与控制器

创建Spring Starter Project

如果https://start.spring.io链接无效，可以选择https://start.aliyun.com

项目结构

启动类

启动类是程序的执行入口
例子1
Demo1Application.java

package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
@SpringBootApplication
public class Demo1Application {
    public static void main(String[] args) {
        SpringApplication.run(Demo1Application.class, args);
    }
}

例子2
遍历项目初始化后添加到项目的所有Bean

 public static void main(String[] args) {
	    ConfigurableApplicationContext context = SpringApplication.run(Demo1Application.class, args);
	    String[] beans = context.getBeanDefinitionNames();
	    for (String bean:beans) {
	    	   System.out.println(bean);
	    }
	 }

一百多个bean中包含了
demo1Application
helloController
homeController

控制器

控制器一 HomeController

package com.example.demo;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HomeController {
	@RequestMapping("/")
	public String home() {
		return "Home Controller";
	}
}

控制器二 HelloController

package com.example.demo;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
	@GetMapping("/hello")
	public String hello() {
		return "<h1>Hello Controller</h1>";
	}

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>demo-1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo-1</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.6.13</spring-boot.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>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>17</source>
                    <target>17</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
                <configuration>
                    <mainClass>com.example.demo.Demo1Application</mainClass>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>