How does springboot read attribute values in the configuration file (ES1en.yml)

In spring boot, take a few simple steps to read the various types of attribute values in the configuration file (ES3en.yml) :

1. Introduction of dependencies:

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

2. Configure the values of each attribute in the configuration file (application.yml) :

myProps: # Custom properties and values  
 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. Create an bean to receive configuration information:

@Component 
@ConfigurationProperties(prefix="myProps") // receive application.yml In the myProps The following properties  
public class MyProps { 
  private String simpleProp; 
  private String[] arrayProps; 
  private List<Map<String, String>> listProp1 = new ArrayList<>(); // receive prop1 The value of the property inside  
  private List<String> listProp2 = new ArrayList<>(); // receive prop2 The value of the property inside  
  private Map<String, String> mapProps = new HashMap<>(); // receive prop1 The value of the property inside  
   
  public String getSimpleProp() { 
    return simpleProp; 
  } 
   
  //String The type of 1 Will need to setter To receive the value of the property; maps, collections,  and  arrays  Don't need  
  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; 
  } 
} 

Once started, the properties in bean will automatically receive the configured values.

4. Unit Test Cases:

@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())); 
  } 

Test results:

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"} 

Source code reference: https: / / github com xujijun/my spring -- boot