小编典典

在Spring Boot中从属性文件注入值数组

spring-boot

好吧,所以我有一个config.properties..:

market.curpairs[0].name=EuroDollar
market.curpairs[0].symbol=EURUSD
market.curpairs[0].minamount=0.1
market.curpairs[1].name=EuroFranken
market.curpairs[1].symbol=EURCHF
market.curpairs[1].minamount=0.1
market.currs[0].name=Euro
market.currs[0].symbol=EUR
market.currs[0].minamount=1.0
market.currs[0].withfee=0.1
market.currs[1].name=Dollar
market.currs[1].symbol=USD
market.currs[1].minamount=1.0
market.currs[1].withfee=0.1
market.currs[2].name=Franken
market.currs[2].symbol=CHF
market.currs[2].minamount=1.0
market.currs[2].withfee=0.1

然后我尝试将其注入MarketConfig.java

@PropertySource("classpath:config.properties")
@ConfigurationProperties(prefix = "market")
@Validated
public class MarketConfig {

    // the configured currencies
    private List<MarketCurrency> currs;

    // the configured currencypairs
    private List<MarketCurrencypair> curpairs;

  /* static classes */
  public static class MarketCurrency {
    String name;
    String symbol;
    double minamount;
    // getter and setter ommitted
  }
  public static class MarketCurrencypair {
    String name;
    String symbol;
    double minamount;
    double withfee;
    // getter and setter ommitted
  }
  // getter and setter ommitted
}

..然后用于MarketService.java

 @Service
    public class MarketService implements IMarketService {

        private final MarketConfig config;

        // ....

         public MarketService(MarketConfig config) {
            this.config = config;
         }
        // ....
        public void printConfig() {
           System.out.println("________________ CONFIGURATION: ");
           this.config.getCurpairs().forEach(System.out::println);
           this.config.getCurrs().forEach(System.out::println);
        }
    }

…由调用Applicationmain

@SpringBootApplication
@EnableSwagger2
@ComponentScan
@EnableConfigurationProperties({MarketConfig.class})
public class MarketApplication implements CommandLineRunner {

    private final MarketService service;

    /**
     * Constructor
     * @param service  ..the Service
     */
    public MarketApplication(MarketService service) {
        this.service = service;
    }

    public static void main(String[] args) {
        SpringApplication.run(MarketApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        this.service.printConfig();
    }
}

…让我屈服 NullPointerException

Caused by: java.lang.NullPointerException: null
    at forex.market.service.MarketService.printConfig(MarketService.java:67) ~[classes/:na]

问题1: 基本上我做对了吗?

问题2: 我在互联网上找不到如何处理属性文件中原始元组数组的任何帮助,甚至有可能将其注入到spring-boot配置中-
还是我需要使用以下命令将配置重写为字符串split()获取单个值(出于维护性和可读性的考虑,我真的不想这么做)?

在此先感谢-如果您错过了一些信息/来源,请发表评论,我会尽快提供。


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2020-05-30

共1个答案

小编典典

您需要设置 属性前缀 ,不需要 @Configuration@Component, 并使用嵌入式 公共静态类 包装货币的属性

 @PropertySource("classpath:config.properties")
 @ConfigurationProperties(prefix = "market")
 @Validated
 public class MarketConfig {
      List<MarketCurrency> currs;
      //getters setters

      public static class MarketCurrency {

          String name;
          String symbol;
        ....
//getters setters

将MarketConfig.class添加到@EnableConfigurationProperties

 @SpringBootApplication
 @EnableSwagger2
 @EnableConfigurationProperties({MarketConfig.class})
 public class MarketApplication implements CommandLineRunner {

    private final MarketService service;
    private final MarketConfig config;

    public MarketApplication(MarketService service, MarketConfig config) {
       this.service = service;
       this.config = config;
    }
2020-05-30