SpringBoot03(读取配置内容)

SpringBoot读取propriety/yml/yaml配置中的内容

3种方法

方法1 @value

@RestController
public class HelloController {

/*@Value("${XXXX}") 这个是@Value的固定格式，XXXX是配置在propriety/yml/yaml里面的内容
拿yml里面的文件举例子：
name1: 李四
person:
  name: chen
  age: 18
这样就有下面的 @Value("${name1}")和 @Value("${person.name}")和 @Value("${person.age}")
*/

    @Value("${name1}")
    private String name;

    @Value("${person.name}")
    private String name2;

    @Value("${person.age}")
    private int age;

    @Value("${address[0]}")
    private String address;

    @Value("${msg1}")
    private String msg1;

    @Value("${msg2}")
    private String msg2;


    @RequestMapping("hello2")
    public String Hello2() {
        System.out.println(" --> " + name);
        System.out.println(" --> " + name2);
        System.out.println(" --> " + age);
        System.out.println(" --> " + address);
        System.out.println(" --> " + msg1);
        System.out.println(" --> " + msg2);
        return "hello_SpringBoot";
    }

方法2：Environment

/*
1-用@Autowired
      private Environment environment;

2-调用方法：environment.getProperty("XXXX")  
//这个XXXX是propriety/yml/yaml里面的配置名，如果不懂请参考@Value里面的代码备注

*/
@RestController
public class HelloController {

    @Autowired
    private Environment environment;

    @RequestMapping("hello3")
    public String Hello3() {
        System.out.println(environment.getProperty("name1"));
        System.out.println(environment.getProperty("address[0]"));
        return "hello_SpringBoot3";
    }

方法3：@ConfigurationProperties

1-propriety/yml/yaml配置信息

#只是拿这个person来举例子
person:
  name: chen
  age: 18
  address:
    - fuzhou
    - jiangxi

2-我们现在需要把这个配置文件里面的person用@ConfigurationProperties方法读取出来，首先需要写一个Person的类

/*
1-先把propriety/yml/yaml里面需要配置的东西写成一个`类`
2- private String name;和 private int age;里面的name、age是propriety/yml/yaml里面名字一样的
eg：propriety/yml/yaml里面是这样:
person:
  name: chen
  age: 18
  address:
    - fuzhou
    - jiangxi
 */


@Component
@ConfigurationProperties(prefix = "person")
//@ConfigurationProperties(prefix = "person") 这个需要定义：定义一下你需要导入的是哪个配置，我这个和注释一样导入person，一般和这个类名定义一致
public class Person {
    private String name;
    private int age;
    private String[] address;

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", address=" + Arrays.toString(address) +
                '}';
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String[] getAddress() {
        return address;
    }

    public void setAddress(String[] address) {
        this.address = address;
    }


}

3-把他打印出来（因为1-类有get、set方法，又因为2-@ConfigurationProperties(prefix = "person")）把配置文件内容赋值给Person类了，所以直接打印出来就是配置文件的内容了）

@RestController
public class HelloController {

    @Autowired
    private Person person;

    @RequestMapping("hello4")
    public String Hello4() {

        System.out.println(person);//把类的信息打印出来

        String[] address = person.getAddress();
        for (String add:address) {
            System.out.println(add);
        }
        return "hello_SpringBoot4";
    }

}

4-出现的问题：在自定义的Person类中

解决：
1-点击Open Documentation
2-找到这个依赖

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

3-加到pom.xml里面

4-效果：以后写配置文件会有提示