SpringBoot创建项目入门案例

目录结构

一、创建SpringBoot项目

1.创建骨架名称

2.给项目命名

3.配置pom.xml文件

4.MySql的驱动包

5.自动生成的pom.xml文件

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.3.0.RELEASE
         
    
    com.william
    keepmoving
    0.0.1-SNAPSHOT
    keepmoving
    Demo project for Spring Boot

    
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            mysql
            mysql-connector-java
            runtime
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
            
                
                    org.junit.vintage
                    junit-vintage-engine
                
            
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

二、写入demo

package com.william.keepmoving.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author ：lijunxuan
 * @date ：Created in 2020/5/27  22:42
 * @description ：
 * @version: 1.0
 */
@RestController
public class HoldOnLife {
    @RequestMapping("/hello")
    public String hello(){
        return "hello";

    }


}

三、启动项目

发起请求
http://localhost:8080/hello

响应的页面

四、Spring的自动配置

五、yml文件的使用

特殊的单词出现的问题

home 会输出本地的home
country 会输出国家的英文简称

yml的两种注入方式

1.实体类注入

创建实体类

1.加入注解
@Component
@ConfigurationProperties(prefix = “user”)
2.加入以上两个注解时需要在pom.xml文件中加入配置处理器依赖
不加配置处理器依赖会提示

        
        
            org.springframework.boot
            spring-boot-configuration-processor
            true
        

3.user要和yml文件中的user相同，user实体类要加入对应的get(),set()方法
4.点击实体类中的图标会跳转到yml文件对应的字段

package com.william.keepmoving.domain;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import java.util.Arrays;

/**
 * @author ：lijunxuan
 * @date ：Created in 2020/5/28  22:26
 * @description ：
 * @version: 1.0
 */
@Component
@ConfigurationProperties(prefix = "user")
public class User {
    private String city;
    private String country;
    private String[] home;
    private String time;
    private String ip;
    private String password;
    private String test;

    @Override
    public String toString() {
        return "User{" +
                "city='" + city + '\'' +
                ", country='" + country + '\'' +
                ", home=" + Arrays.toString(home) +
                ", time='" + time + '\'' +
                ", ip='" + ip + '\'' +
                ", password='" + password + '\'' +
                ", test='" + test + '\'' +
                '}';
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String[] getHome() {
        return home;
    }

    public void setHome(String[] home) {
        this.home = home;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        this.ip = ip;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getTest() {
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }
}

在yml文件中加入特定值

测试类需要注入

2.注解注入

在yml文件中配置

只需要在测试类中加入注解@value配置就可以了

六、数组

yml文件

实体类

package com.william.keepmoving.domain;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import java.util.Arrays;

/**
 * @author ：lijunxuan
 * @date ：Created in 2020/5/28  22:26
 * @description ：
 * @version: 1.0
 */
@Component
@ConfigurationProperties(prefix = "user")
public class User {
    private String city;
    private String country;
    private String[] home1;
    private String time;
    private String ip;
    private String password;
    private String test;

    @Override
    public String toString() {
        return "User{" +
                "city='" + city + '\'' +
                ", country='" + country + '\'' +
                ", home1=" + Arrays.toString(home1) +
                ", time='" + time + '\'' +
                ", ip='" + ip + '\'' +
                ", password='" + password + '\'' +
                ", test='" + test + '\'' +
                '}';
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String[] getHome1() {
        return home1;
    }

    public void setHome1(String[] home1) {
        this.home1 = home1;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        this.ip = ip;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getTest() {
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }
}

执行后的效果