在SpringBoot 中从application.yml中获取自定义常量方式

 <!-- 支持 @ConfigurationProperties 注解 -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-configuration-processor</artifactId>
 <optional>true</optional>
 </dependency>

myProps: #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 

@Component 
@ConfigurationProperties(prefix="myProps") //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; 
 } 
} 

@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())); 
 } 

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"} 

image:
 location: D:/images/
 /**
 * 在配置文件中配置的文件保存路径
 */
 @Value("${image.location}")
 private String location;