Java精简笔记6

1.springboot项目搭建

①创建maven工程
②选择springboot的版本
pom文件中：

<dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>2.7.6</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
</dependencyManagement>

③整合springmvc用到的包，添加启动器
（以前绝大多数xml配置文件）
pom文件中：

<dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <version>2.7.6</version>
    </dependency>
</dependencies>

④开发一个Controller

@Controller
public class MyController {
    @RequestMapping("/test01")
    @ResponseBody
    public String test01(){
        return "hi,springboot";
    }
}

⑤启动类编写

@SpringBootApplication

public class TestSpringBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(TestSpringBootApplication.class,args);
    }
}

⑥运行，浏览器访问测试

2.springboot配置文件

3.springboot版本--案例--书城

①导入依赖

  <dependencies>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <version>2.7.6</version>
    </dependency>

    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.1.3</version>
    </dependency>

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.21</version>
    </dependency>

  </dependencies>

②编写配置文件

server:
  port: 8888
  servlet:
    context-path: /springbootssm
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/wiki?useSSL=false&characterEncoding=utf8&serverTimezone=GMT%2B8
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root

③编写实体类，配置文件中加入别名

mybatis:
  type-aliases-package: com.msb.pojo

④定义mapper接口

public interface BookMapper {
     List selectAllBooks();
}

⑤定义mapper.xml映射文件(resources下mybatis包下BookMapper.xml文件)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.msb.mapper.BookMapper">
    <!--id是方法名字  resultType是实体类的路径-->
    <select id="selectAllBooks" resultType="com.msb.pojo.Book">
        select * from t_book
    </select>
</mapper>

⑥配置文件中加入映射文件位置

mapper-locations: classpath: mybatis/*.xml

⑦定义启动类，在启动类中加入mapper的包扫描

@SpringBootApplication
@MapperScan("com.msb.mapper")

public class TestSpringBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(TestSpringBootApplication.class,args);
    }
}

⑧Service层接口及实现类

public interface BookService {
    List findAllBooks();
}

⑨Service层实现类

@Service

public class BookServiceImpl implements BookService {
    @Autowired
    private BookMapper bookMapper;
    public List findAllBooks() {
        return bookMapper.selectAllBooks();
    }
}

⑩Controller层

@Controller
public class BookController {
    @Autowired
    private BookService bookService;
    @RequestMapping("/findBooks")
    @ResponseBody
    public String findBooks(){
        List list = bookService.findAllBooks();
        String s = "";
        for (int i = 0; i < list.size(); i++) {
             Book b = (Book)list.get(i);
             s += b.getName();
             s += b.getAuthor();
        }
        return s;
    }
}

11.测试