springboot如何读取配置文件（application.yml）中的属性值

1、引入依赖：maven
<!-- 支持 @ConfigurationProperties 注解 -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-configuration-processor</artifactId>
  <optional>true</optional>
</dependency>
引入依赖：ｇｒａｄｌｅ
compile('org.springframework.boot:spring-boot-configuration-processor')


2、配置文件（application.yml）中配置各个属性的值：
myPropss: #自定义的属性和值
simpleProp: simplePropValue
arrayProps: 1,2,3,4,5
listProp1:
  - name: abc
   value: abcValue
  - name: efg
   value: efgValue
listProp2:
  - config2Value1
  - config2Vavlue2
mapProps:
  key1: value1
  key2: value2

3、创建一个bean来接收配置信息
@Component
@ConfigurationProperties(prefix="myPropss") //接收application.yml中的myProps下面的属性
public class MyProps {
  private String simpleProp;
  private String[] arrayProps;
  private List<Map<String, String>> listProp1 = new ArrayList<>(); //接收prop1里面的属性值
  private List<String> listProp2 = new ArrayList<>(); //接收prop2里面的属性值
  private Map<String, String> mapProps = new HashMap<>(); //接收prop1里面的属性值
   
  public String getSimpleProp() {
    return simpleProp;
  }
   
  //String类型的一定需要setter来接收属性值；maps, collections, 和 arrays 不需要
  public void setSimpleProp(String simpleProp) {
    this.simpleProp = simpleProp;
  }
   
  public List<Map<String, String>> getListProp1() {
    return listProp1;
  }
  public List<String> getListProp2() {
    return listProp2;
  }
 
  public String[] getArrayProps() {
    return arrayProps;
  }
 
  public void setArrayProps(String[] arrayProps) {
    this.arrayProps = arrayProps;
  }
 
  public Map<String, String> getMapProps() {
    return mapProps;
  }
 
  public void setMapProps(Map<String, String> mapProps) {
    this.mapProps = mapProps;
  }
}

4、单元测试用例：
@Autowired
  private MyProps myProps; 
   
  @Test
  public void propsTest() throws JsonProcessingException {
    System.out.println("simpleProp: " + myProps.getSimpleProp());
    System.out.println("arrayProps: " + objectMapper.writeValueAsString(myProps.getArrayProps()));
    System.out.println("listProp1: " + objectMapper.writeValueAsString(myProps.getListProp1()));
    System.out.println("listProp2: " + objectMapper.writeValueAsString(myProps.getListProp2()));
    System.out.println("mapProps: " + objectMapper.writeValueAsString(myProps.getMapProps()));
  }

测试结果：
simpleProp: simplePropValue
arrayProps: ["1","2","3","4","5"]
listProp1: [{"name":"abc","value":"abcValue"},{"name":"efg","value":"efgValue"}]
listProp2: ["config2Value1","config2Vavlue2"]
mapProps: {"key1":"value1","key2":"value2"}