==================
YAML读取之单个对象
==================

1 YAML中的对象

/src/main/resources/application.yml：

...
datasource:
  driver: com.mysql.jdbc.Driver
  url: jdbc:mysql://localhost/springbootdb
  username: root
  password: 123456
...

2 创建用于表示YAML对象的实体类

/src/main/java/cn/tedu/springboot/entity/DataSource.java：

public class DataSource {
    private String driver;
    private String url;
    private String username;
    private String password;

    public String getDriver() {
        return driver;
    }

    public void setDriver(String driver) {
        this.driver = driver;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

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

    @Override
    public String toString() {
        return "DataSource{" +
            "driver='" + driver + '\'' +
            ", url='" + url + '\'' +
            ", username='" + username + '\'' +
            ", password='" + password + '\'' +
            '}';
    }
}

类的属性名必须与YAML对象中的属性名严格一致。

3 将实体类对象交由Spring管理

/src/main/java/cn/tedu/springboot/entity/DataSource.java：

...
@Component
...
public class DataSource {
    ...
}

4 指定装载到实体类对象中的数据

...
@ConfigurationProperties("datasource")
...
public class DataSource {
    ...
}

5 读取YAML中的单个对象

...
public class BookController {
    ...
    // YAML读取之单个对象
    @Autowired
    private DataSource dataSource;
    ...
    @GetMapping
    public String getBooks() {
        ...
        System.out.println(dataSource);
        ...
    }
    ...
}

6 不是必须的

在/pom.xml文件中添加依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-configuration-processor</artifactId>
    <optional>true</optional>
</dependency>

例程：springboot_04_yaml