springboot使用入门

Posted 2021-02-19 囧囧x鑫

 

1.创建maven工程，引入依赖

    <!-- 所有的springboot的工程都以spring父工程为父工程 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
    </parent>

2.引入SpringBoot提供的自动配置依赖

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

3.添加全局引导类，并使用@SpringBootApplication注解

@SpringBootApplication  // 相当于 EnableAutoConfiguration + ComponentScan + SpringbootConfiguration
public class MySpringBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(MySpringBootApplication.class, args);
    }
}

4.引入druid依赖

<dependency>
    <groupId>com.github.drtrang</groupId>
    <artifactId>druid-spring-boot2-starter</artifactId>
    <version>1.1.10</version>
</dependency>

5.添加jdbc.properties配置文件

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/springboottest
jdbc.username=root
jdbc.password=root

6使用 @Autowired注入datasource

@Configuration
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {

    @Autowired
    private JdbcProperties jdbcProperties;

    @Bean
    public DataSource dataSource() {

        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(jdbcProperties.getDriverClassName());
        dataSource.setUrl(jdbcProperties.getUrl());
        dataSource.setUsername(jdbcProperties.getUsername());
        dataSource.setPassword(jdbcProperties.getPassword());
        return dataSource;
    }
}

7.添加连接池 

只需要在pom中找到springboot提供的启动器

<!--jdbc的启动器，默认使用HikariCP连接池-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!--不要忘记数据库驱动，因为springboot不知道我们使用的什么数据库，这里选择mysql-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

8.指定连接池参数 

在resource目录下创建：application.properties配置文件

# 连接四大参数
spring.datasource.url=jdbc:mysql://localhost:3306/springboottest
spring.datasource.username=root
spring.datasource.password=root
# 可省略，SpringBoot自动推断
spring.datasource.driverClassName=com.mysql.jdbc.Driver

9.使用druid连接池

<!-- Druid连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.10</version>
</dependency>

在application.properties中添加一些连接属性

#初始化连接数
spring.datasource.druid.initial-size=1
#最小空闲连接
spring.datasource.druid.min-idle=1
#最大活动连接
spring.datasource.druid.max-active=20
#获取连接时测试是否可用
spring.datasource.druid.test-on-borrow=true
#监控页面启动
spring.datasource.druid.stat-view-servlet.allow=true

10.整合mybatis

<!--mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

10.1配置 mybatis别名扫描

# mybatis 别名扫描
mybatis.type-aliases-package=cn.test.pojo

10.2编写dao类

@Mapper
public interface UserMapper {
}

11.通用mapper

引入启动类

<!-- 通用mapper -->
<dependency>
    <groupId>tk.mybatis</groupId>
    <artifactId>mapper-spring-boot-starter</artifactId>
    <version>2.0.2</version>
</dependency>

12.编写server类　　注意添加事务@Transactional

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public User queryUserById(Long id){
        return this.userMapper.selectByPrimaryKey(id);
    }
    @Transactional
    public void  deleteUserById(Long id){
        this.userMapper.deleteByPrimaryKey(id);
    }
}

13编写controller类

@RestController
@RequestMapping("User")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("{id}")
    @ResponseBody
    public User queryUserById(@PathVariable("id")Long id){
        return this.userService.queryUserById(id);
    }
}

 

application.properties配置文件

server.port=8888
spring.mvc.static-path-pattern=/**
# 这个配置是为了能访问resource/static/目录下的静态资源

# 连接四大参数
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=root
# 可省略，SpringBoot自动推断
spring.datasource.driverClassName=com.mysql.jdbc.Driver
#初始化连接数
spring.datasource.druid.initial-size=1
#最小空闲连接
spring.datasource.druid.min-idle=1
#最大活动连接
spring.datasource.druid.max-active=20
#获取连接时测试是否可用
spring.datasource.druid.test-on-borrow=true
#监控页面启动
spring.datasource.druid.stat-view-servlet.allow=true

# mybatis 别名扫描
mybatis.type-aliases-package=com.test.pojo

pom.xml配置文件

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.test.springboot2</groupId>
    <artifactId>itest</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--不要忘记数据库驱动，因为springboot不知道我们使用的什么数据库，这里选择mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- Druid连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <!--mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!-- 通用mapper -->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.0.2</version>
        </dependency>
    </dependencies>

</project>

结束!