Spring Boot下优雅的将配置参数读取出来

假设在application.yml中写入了以下配置参数

wechat:
  pay:
    appId:
    mchId:
    mchKey:
    subAppId:
    subMchId:
    keyPath:

我们可以通过wechat.pay作为前缀，将配置信息读取出来

@ConfigurationProperties(prefix = "wechat.pay")
public class WxPayProperties {
  /**
   * 设置微信公众号的appid
   */
  private String appId;

  /**
   * 微信支付商户号
   */
  private String mchId;

  /**
   * 微信支付商户密钥
   */
  private String mchKey;

  /**
   * 服务商模式下的子商户公众账号ID，普通模式请不要配置，请在配置文件中将对应项删除
   */
  private String subAppId;

  /**
   * 服务商模式下的子商户号，普通模式请不要配置，最好是请在配置文件中将对应项删除
   */
  private String subMchId;

  /**
   * apiclient_cert.p12文件的绝对路径，或者如果放在项目中，请以classpath:开头指定
   */
  private String keyPath;

  public String getAppId() {
    return this.appId;
  }

  public void setAppId(String appId) {
    this.appId = appId;
  }

  public String getMchId() {
    return mchId;
  }

  public void setMchId(String mchId) {
    this.mchId = mchId;
  }

  public String getMchKey() {
    return mchKey;
  }

  public void setMchKey(String mchKey) {
    this.mchKey = mchKey;
  }

  public String getSubAppId() {
    return subAppId;
  }

  public void setSubAppId(String subAppId) {
    this.subAppId = subAppId;
  }

  public String getSubMchId() {
    return subMchId;
  }

  public void setSubMchId(String subMchId) {
    this.subMchId = subMchId;
  }

  public String getKeyPath() {
    return this.keyPath;
  }

  public void setKeyPath(String keyPath) {
    this.keyPath = keyPath;
  }

  @Override
  public String toString() {
    return ToStringBuilder.reflectionToString(this,
        ToStringStyle.MULTI_LINE_STYLE);
  }
}

然后去使用这些配置信息进行业务中的初始化

@Configuration
@ConditionalOnClass(WxPayService.class)
@EnableConfigurationProperties(WxPayProperties.class)
public class WxPayConfiguration {
  @Autowired
  private WxPayProperties properties;

  @Bean
  @ConditionalOnMissingBean
  public WxPayConfig payConfig() {
    WxPayConfig payConfig = new WxPayConfig();
    payConfig.setAppId(this.properties.getAppId());
    payConfig.setMchId(this.properties.getMchId());
    payConfig.setMchKey(this.properties.getMchKey());
    payConfig.setSubAppId(StringUtils.trimToNull(this.properties.getSubAppId()));
    payConfig.setSubMchId(StringUtils.trimToNull(this.properties.getSubMchId()));
    payConfig.setKeyPath(this.properties.getKeyPath());

    return payConfig;
  }

  @Bean
  //@ConditionalOnMissingBean
  public WxPayService wxPayService(WxPayConfig payConfig) {
    WxPayService wxPayService = new WxPayServiceImpl();
    wxPayService.setConfig(payConfig);
    return wxPayService;
  }

}