Spring Boot @Value属性 [英] Spring Boot @Value Properties

问题描述

我有一个Spring Boot应用程序，在其中一个类中，我尝试使用@Value从application.properties文件中引用一个属性.但是，该属性未解决.我看过类似的帖子，并尝试按照建议进行操作，但这无济于事.该类是:

I have a Spring Boot application and in one of the classes, I try to reference a property from the application.properties file using @Value. But, the property does not get resolved. I have looked at similar posts and tried following the suggestions, but that didn't help. The class is:

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class PrintProperty {

  @Value("${file.directory}")
  private String fileDirectory;

  public void print() {
    System.out.println(fileDirectory);
  }
}

我在application.properties中具有属性file.directory.我也有其他领域.

I have the property file.directory in application.properties. I have other fields as well.

推荐答案

我遇到了与您相同的问题.这是我的错误代码.

I had the same problem like you. Here's my error code.

@Component
public class GetExprsAndEnvId {
    @Value("hello")
    private String Mysecret;


    public GetExprsAndEnvId() {
        System.out.println("construct");
    }


    public void print(){
        System.out.println(this.Mysecret);
    }


    public String getMysecret() {
        return Mysecret;
    }

    public void setMysecret(String mysecret) {
        Mysecret = mysecret;
    }
}

这没问题，但是 我们需要像这样使用它:

This is no problem like this, but we need to use it like this:

@Autowired
private GetExprsAndEnvId getExprsAndEnvId;

不是这样的:

getExprsAndEnvId = new GetExprsAndEnvId();

在这里，用@Value注释的字段为null，因为Spring不知道用new创建的GetExprsAndEnvId的副本，也不知道如何在其中注入值.

Here, the field annotated with @Value is null because Spring doesn't know about the copy of GetExprsAndEnvId that is created with new and didn't know to how to inject values in it.

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