Spring-Boot多模块项目加载属性文件 [英] Spring-Boot multi module project load property-file

问题描述

我在Maven中有一个Spring-Boot-Application作为多模块项目.结构如下:

I have a Spring-Boot-Application as a multimodule-Project in maven. The structure is as follows:

Parent-Project
|--MainApplication
|--Module1
|--ModuleN

在MainApplication项目中，存在用@SpringBootApplication注释的main()方法类，依此类推.与往常一样，该项目具有一个application.properties文件，该文件会自动加载.因此，我可以使用@Value批注

In the MainApplication project there is the main() method class annotated with @SpringBootApplication and so on. This project has, as always, an application.properties file which is loaded automatically. So I can access the values with the @Value annotation

@Value("${myapp.api-key}")
private String apiKey;

在我的Module1中，我也想使用一个属性文件(称为module1.properties)，用于存储模块配置.该文件只能在模块中访问和使用.但是我无法加载它.我用@Configuration和@PropertySource尝试了一下，但是没有运气.

Within my Module1 I want to use a properties file as well (called module1.properties), where the modules configuration is stored. This File will only be accessed and used in the module. But I cannot get it loaded. I tried it with @Configuration and @PropertySource but no luck.

@Configuration
@PropertySource(value = "classpath:module1.properties")
public class ConfigClass {

如何使用Spring-Boot加载属性文件并轻松访问值?找不到有效的解决方案.

How can I load a properties file with Spring-Boot and access the values easily? Could not find a valid solution.

我的配置

@Configuration
@PropertySource(value = "classpath:tmdb.properties")
public class TMDbConfig {

    @Value("${moviedb.tmdb.api-key}")
    private String apiKey;

    public String getApiKey() {
        return apiKey;
    }

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }
}

调用配置

@Component
public class TMDbWarper {

@Autowired
private TMDbConfig tmdbConfig;

private TmdbApi tmdbApi;

public TMDbWarper(){
    tmdbApi = new TmdbApi(tmdbConfig.getApiKey());
}

自动连接整经器时，构造函数中出现NullPointerException.

I'm getting an NullPointerException in the constructor when I autowire the warper.

推荐答案

用于字段注入:

在构造任何bean之后，调用任何配置方法之前立即注入字段.这样的配置字段不必是公共的.请参考自动装配注释以获得完整用法.在这种情况下，请使用构造函数注入，如下所示:

Fields are injected right after construction of a bean, before any config methods are invoked. Such a config field does not have to be public. Refer Autowired annotation for complete usage. Use constructor injection in this case like below:

@Component
public class TMDbWarper {

    private TMDbConfig tmdbConfig;

    private TmdbApi tmdbApi;

    @Autowired
    public TMDbWarper(final TMDbConfig tmdbConfig){
            this.tmdbConfig = tmdbConfig;
            tmdbApi = new TmdbApi(tmdbConfig.getApiKey());
    }

(或)

使用@PostConstruct进行如下初始化:

@Component
public class TMDbWarper {

    @Autowired
    private TMDbConfig tmdbConfig;

    private TmdbApi tmdbApi;

    @PostConstruct
    public void init() {
        // any initialisation method
        tmdbConfig.getConfig();
    }

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