属性源未自动连接

Question

出于某种原因，我使用外部属性源，其中一个外部属性源没有自动连接，在创建身份验证bean时接收空指针

原因： org.springframework.beans.BeanInstantiationException： Failed to instanceiate [com.filechecker.check.Authenticator]： Constructor threw exception;nested exception is java.lang.NullPointerException

Caused by： java.lang.NullPointerException： null at com.filechecker.check.Authenticator.（身份验证器.java：30） ~[类！/：0.0.1-快照]

    String username = emailPropertyConfig.getEmailConfig().getUsername();

@Component
@PropertySource(value="${email.app.properties}",ignoreResourceNotFound = false)
@ConfigurationProperties
public class PropertyEmailConfiguration {

    private EmailConfig emailConfig =  new EmailConfig();

    public EmailConfig getEmailConfig() {
        return emailConfig;
    }

    public void setEmailConfig(EmailConfig emailConfig) {
        this.emailConfig = emailConfig;
    }
}


@Component
public class Authenticator extends javax.mail.Authenticator {

    @Autowired
    PropertyEmailConfiguration emailPropertyConfig;

    @Autowired
    CipherCrypt cipherCrypt;

    private PasswordAuthentication authentication;

    public Authenticator() throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeySpecException {

        String username = emailPropertyConfig.getEmailConfig().getUsername();
        String password = cipherCrypt.decrypt(emailPropertyConfig.getEmailConfig().getEncryptPassword());
        authentication = new PasswordAuthentication(username, password);
    }

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
        return authentication;
    }
}

@Component
@PropertySource(value="${external.app.properties}", ignoreResourceNotFound = true)
@ConfigurationProperties
public class PropertyConfiguration {

    private List<FileStructureConfig> fileStructureConfig = new ArrayList();

    private List<EmailSendingProperties> emailSendingProperties  = new ArrayList();

    public List<FileStructureConfig> getFileStructureConfig() {
        return fileStructureConfig;
    }

    public void setFileStructureConfig(List<FileStructureConfig> fileStructureConfig) {
        this.fileStructureConfig = fileStructureConfig;
    }

    public List<EmailSendingProperties> getEmailSendingProperties() {
        return emailSendingProperties;
    }

    public void setEmailSendingProperties(List<EmailSendingProperties> emailSendingProperties) {
        this.emailSendingProperties = emailSendingProperties;
    }


}

Answer 1

您正在尝试访问构造函数中的@Autowired属性。在此阶段无法自动连接属性。为了让Spring“烘焙bean”，Spring必须创建您的对象（使用您的构造函数），然后才应用自动连接机制来注入＜code＞emailPropertyConfig。因此，您无法访问构造函数中的两个＜code>@Autowired＜code＞属性。

如果您需要从电子邮件中提取一些值PropertyConfig或cipherCrypt，则可以@PostConstruct

@Component
public class Authenticator {

    @Autowired
    PropertyEmailConfiguration emailPropertyConfig;

    @Autowired
    CipherCrypt cipherCrypt;

    private PasswordAuthentication authentication;

    @PostConstruct
    void init() throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeySpecException {

      String username = emailPropertyConfig.getEmailConfig().getUsername();
      String password = cipherCrypt.decrypt(emailPropertyConfig.getEmailConfig().getEncryptPassword());
      authentication = new PasswordAuthentication(username, password);
    }

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
      return authentication;
    }
}

或使用构造函数注入：

@Component
public class Authenticator {

    PropertyEmailConfiguration emailPropertyConfig;

    CipherCrypt cipherCrypt;

    private PasswordAuthentication authentication;

    public Authenticator(PropertyEmailConfiguration emailPropertyConfig, CipherCrypt cipherCrypt) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeySpecException {

      String username = emailPropertyConfig.getEmailConfig().getUsername();
      String password = cipherCrypt.decrypt(emailPropertyConfig.getEmailConfig().getEncryptPassword());
      authentication = new PasswordAuthentication(username, password);
    }

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
      return authentication;
    }
}