后端搭建

创建springboot项目

管理maven

setting——maven

添加依赖

<dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.6</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.76</version>
        </dependency>
    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <-- 修改完这里热部署才会生效--!>
                <configuration>
                    <executable>true</executable>
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>

热更新、热加载

1. 修改Registry
   ctrl shift a 搜索registry 找到compiler.automake.allow.when.app.running 打上√
2. 执行快捷键 Ctrl f9才进行热加载

配置application.xml

server.port=8888
spring.datasource.url=jdbc:mysql://localhost:3306/music?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

跨域配置

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")  //哪些目录可以使用跨域访问
                allowedOriginPatterns("*")          //允许哪些网站访问
                .allowedMethods("*")          //允许哪些方法访问
                .allowCredentials(true);      //访问是否需要验证
    }
}

在启动类加注解@MapperScan("mapper接口包名")

配置mybatis配置文件

//实体类包名，使用resultType时可以直接写个类名就OK了
mybatis.type-aliases-package=com.music.entity
mybatis.mapper-locations=classpath:mapper/*.xml

###如果还存在跨域问题，在controller加上`@CrossOrigin`注解