SnakeYaml“无法找到属性错误”

Question

这是我的 config.yml 的一部分：

#Authenctication
AuthenticationConfig:
  AuthencticationType: LDAP
  LDAPConfig:
     LDAPUrl: ldap://localhost:389
     ConnectionType: simple
     LDAPSecurityConfig:
        RootDN: cn=manager,dc=maxcrc,dc=com
        RootPassword: secret
        UserSearchDN: ou=People,dc=maxcrc,dc=com
        GroupdSearchDB: ou=Groups,dc=maxcrc,dc=com

我有一个用于解析的类：

public class YamlConfiguraiton {
    private AuthenticationConfiguration AuthenticationConfig;

    public void setAuthenticationConfig(AuthenticationConfiguration AuthenticationConfig) {
        this.AuthenticationConfig = AuthenticationConfig;
    }

    public AuthenticationConfiguration getAuthenticationConfig() {
        return this.AuthenticationConfig;
    }
}

然而，当我跑

try(InputStream in = new FileInputStream(new File(ymalPath))) {
            yamlConfig = yaml.loadAs(in, YamlConfiguraiton.class);
        } catch (IOException e) {
            e.printStackTrace();
        }

发生以下错误：

Exception in thread "main" Cannot create property=AuthenticationConfig for JavaBean=com.ibm.entity.matching.common.bootstrap.YamlConfiguraiton@e7860081
 in 'reader', line 2, column 1:
    AuthenticationConfig:
    ^
Unable to find property 'AuthenticationConfig' on class: com.ibm.entity.matching.common.bootstrap.YamlConfiguraiton
 in 'reader', line 3, column 4:
       AuthencticationType: LDAP
       ^

    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.constructJavaBean2ndStep(Constructor.java:270)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.construct(Constructor.java:149)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructYamlObject.construct(Constructor.java:309)
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObjectNoCheck(BaseConstructor.java:204)
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:193)
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:159)
    at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:146)
    at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:524)
    at org.yaml.snakeyaml.Yaml.loadAs(Yaml.java:518)
    at com.ibm.entity.matching.bootstrap.EntityMatching.boot(EntityMatching.java:55)
    at com.ibm.entity.matching.bootstrap.EntityMatching.main(EntityMatching.java:35)
Caused by: org.yaml.snakeyaml.error.YAMLException: Unable to find property 'AuthenticationConfig' on class: com.ibm.entity.matching.common.bootstrap.YamlConfiguraiton
    at org.yaml.snakeyaml.introspector.PropertyUtils.getProperty(PropertyUtils.java:159)
    at org.yaml.snakeyaml.introspector.PropertyUtils.getProperty(PropertyUtils.java:148)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.getProperty(Constructor.java:287)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.constructJavaBean2ndStep(Constructor.java:208)
    ... 10 more

为什么它抱怨找不到属性 AuthenticationConfig 而 AuthenticationConfig 只是实例变量的名称？

更新 在我将实例变量从“私有”更改为“公共”之后，它们被 SnakeYaml 识别，但这不是我们所期望的。这些类不被识别为 JavaBean。

更新 我找到了根本原因。这是命名约定。如果您希望 SnakeYaml 解析您的 yaml 文件，则必须遵守 camelCase。setter 和 getter 方法的名称也很重要。假设有一个名为 ldapConfig 的私有实例变量，那么它的 getter 和 setter 的名称必须是 getLdapConfig 和 setLdapConfig，即使 getLDAPConfig 和 setLDAPConfig 也不起作用。

Answer 1

错误的主要原因是您需要在 POJO 类（即YamlConfiguraiton）中定义 Yaml 文件中存在的所有属性。

您可以使用下面的代码来跳过未定义的属性。

Representer representer = new Representer();
            representer.getPropertyUtils().setSkipMissingProperties(true);
            Yaml yaml = new Yaml(new Constructor(YamlConfiguraiton.class), representer);

首先，将Yaml文件中的属性名称重命名为camelCase。

请参考以下代码：-

代码：-

public class YamlReadCustom {

    private static String yamlPath = "/authentication.yaml";

    public static void main(String[] args) {
        Representer representer = new Representer();
        representer.getPropertyUtils().setSkipMissingProperties(true);
        Yaml yaml = new Yaml(new Constructor(Authentication.class), representer);
        try(InputStream in = YamlReadCustom.class.getResourceAsStream (yamlPath)) {
            Authentication authentication = yaml.loadAs(in, Authentication.class);
            System.out.println(authentication.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

验证：-

public class Authentication {
    private String authenticationConfig;
    private String authencticationType;
    private LdapConfig ldapConfig;

    //getters and setters
}

Ldap配置：-

public class LdapConfig {
    private String ldapUrl;
    private String connectionType;
    private Map<String, Object> ldapSecurityConfig;
    //getters and setters
}

身份验证.yaml

authenticationConfig:
authencticationType: LDAP
ldapConfig:
  ldapUrl: ldap://localhost:389
  connectionType: simple
  ldapSecurityConfig:
    rootDn: cn=manager,dc=maxcrc,dc=com
    rootPassword: secret
    userSearchDn: ou=People,dc=maxcrc,dc=com
    groupdSearchDb: ou=Groups,dc=maxcrc,dc=com