spring boot 读取配置文件（application.yml）中的属性值

在spring boot中，简单几步，读取配置文件（application.yml）中各种不同类型的属性值：

1、引入依赖：

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

2、配置文件（application.yml）中配置各个属性的值：

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

3、创建一个bean来接收配置信息：

@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;
    }
}

启动后，这个bean里面的属性就会自动接收配置的值了。

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"}