java註解三： .yml 的讀取技巧及獲取檔案介紹
阿新 • • 發佈：2018-12-30
轉：https://zhidao.baidu.com/question/437547082212460524.html
在spring boot中，簡單幾步，讀取配置檔案（application.yml）中各種不同型別的屬性值：
1、引入依賴：
<!-- 支援 @ConfigurationProperties 註解 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
2、配置檔案（application.yml）中配置各個屬性的值：
simpleProp: simplePropValue #單個值
arrayProps: 1,2,3,4,5 #陣列
listProp1: #List集合
- name: abc
value: abcValue
- name: efg
value: efgValue
listProp2:
- config2Value1
- config2Vavlue2
mapProps: #Map集合
key1: value1
key2: value2
3、建立一個bean來接收配置資訊：
@Component
@ConfigurationProperties(prefix="myProps") //接收application.yml中的myProps下面的屬性
public class MyProps {
private String simpleProp;
private String[] arrayProps;
private List<Map<String, String>> listProp1 = new ArrayList<>(); //接收prop1裡面的屬性值
private List<String> listProp2 = new ArrayList<>(); //接收prop2裡面的屬性值
private Map<String, String> mapProps = new HashMap<>(); //接收prop1裡面的屬性值
public String getSimpleProp() { return simpleProp; }
//String型別的一定需要setter來接收屬性值；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; }
}
啟動後，這個bean裡面的屬性就會自動接收配置的值了。
4、單元測試用例：
@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()));
}
測試結果：
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"}