NullPointerException 运行 DataNucleus Enhancer 3.1.0-release答案

【问题标题】：NullPointerException running DataNucleus Enhancer 3.1.0-releaseNullPointerException 运行 DataNucleus Enhancer 3.1.0-release
【发布时间】：2012-08-06 07:06:09
【问题描述】：

我正在从 DOS 运行 DataNucleus 增强器，如下所示：

java -cp C:\Users\Chania\workspace\myproject\war\WEB-INF\classes\;C:\repo\datanucleus-full-3.1.0-release\lib\datanucleus-enhancer-3.1.0-release.jar;C:\repo\datanucleus-full-3.1.0-release\lib\datanucleus-core-3.1.0-release.jar;C:\repo\datanucleus-full-3.1.0-release\deps\jdo-api-3.1-SNAPSHOT-20110926.jar;C:\repo\datanucleus-full-3.1.0-release\lib\datanucleus-api-jdo-3.1.0-release.jar;C:\repo\datanucleus-full-3.1.0-release\deps\log4j-1.2.14.jar;C:\repo\datanucleus-full-3.1.0-release\deps\asm-4.0.jar -Dlog4j.configuration=file:C:\repo\datanucleus-full-3.1.0-release\log4j.properties org.datanucleus.enhancer.DataNucleusEnhancer -v C:\Users\Chania\workspace\myproject\war\WEB-INF\classes\com\myproject\domain\*.class > logfile.txt

我使用的 Java 版本是：

java version "1.6.0_27"

我得到的错误如下：

 ...
 308  [main] DEBUG DataNucleus.Persistence  - Added converter for java.net.URI<->java.lang.String using org.datanucleus.store.types.converters.URIStringConverter
 308  [main] DEBUG DataNucleus.Persistence  - Added converter for java.net.URL<->java.lang.String using org.datanucleus.store.types.converters.URLStringConverter
 309  [main] DEBUG DataNucleus.Persistence  - Added converter for java.util.UUID<->java.lang.String using org.datanucleus.store.types.converters.UUIDStringConverter
 309  [main] DEBUG DataNucleus.Persistence  - TypeConverter for javax.time.calendar.LocalDate<->java.lang.String ignored since java type not present in CLASSPATH
 310  [main] DEBUG DataNucleus.Persistence  - TypeConverter for javax.time.calendar.LocalTime<->java.lang.String ignored since java type not present in CLASSPATH
 311  [main] DEBUG DataNucleus.Persistence  - TypeConverter for javax.time.calendar.LocalTime<->java.lang.Long ignored since java type not present in CLASSPATH
 312  [main] DEBUG DataNucleus.Persistence  - TypeConverter for javax.time.calendar.LocalDateTime<->java.lang.String ignored since java type not present in CLASSPATH
 312  [main] DEBUG DataNucleus.Persistence  - Type converter support loaded
 312  [main] DEBUG DataNucleus.MetaData  - MetaDataManager : Input=(XML,Annotations), XML-Validation=false, XML-Suffices=(persistence=*.jdo, orm=orm, query=*.jdoquery), JDO-listener=false
 338  [main] DEBUG DataNucleus.MetaData  - MetaData Management : Loading Metadata for classes "[com.myproject.domain.Record, com.myproject.domain.RecordSummary, com.myproject.domain.Comment]" ...
 411  [main] DEBUG DataNucleus.MetaData  - Class "com.myproject.domain.Record" has been specified with JDO annotations so using those.
 596  [main] DEBUG DataNucleus.MetaData  - Class "com.myproject.domain.RecordSummary" has been specified with JDO annotations so using those.
 600  [main] DEBUG DataNucleus.MetaData  - Class "com.myproject.domain.Comment" has been specified with JDO annotations so using those.
 Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
604  [main] ERROR DataNucleus.Enhancer  - DataNucleus Enhancer completed with an error. Please review the enhancer log for full details. Some classes may have been enhanced but some caused errors
 Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
org.datanucleus.exceptions.NucleusUserException: Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:536)
    at org.datanucleus.enhancer.DataNucleusEnhancer.getFileMetadataForInput(DataNucleusEnhancer.java:734)
    at org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:525)
    at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1258)
Caused by: java.lang.NullPointerException
    at org.datanucleus.api.jdo.metadata.JDOAnnotationReader.processMemberAnnotations(JDOAnnotationReader.java:1682)
    at org.datanucleus.metadata.annotations.AbstractAnnotationReader.getMetaDataForClass(AbstractAnnotationReader.java:206)
    at org.datanucleus.metadata.annotations.AnnotationManagerImpl.getMetaDataForClass(AnnotationManagerImpl.java:171)
    at org.datanucleus.metadata.MetaDataManager.loadAnnotationsForClass(MetaDataManager.java:2650)
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:496)
    ... 3 more
Nested Throwables StackTrace:
java.lang.NullPointerException
    at org.datanucleus.api.jdo.metadata.JDOAnnotationReader.processMemberAnnotations(JDOAnnotationReader.java:1682)
    at org.datanucleus.metadata.annotations.AbstractAnnotationReader.getMetaDataForClass(AbstractAnnotationReader.java:206)
    at org.datanucleus.metadata.annotations.AnnotationManagerImpl.getMetaDataForClass(AnnotationManagerImpl.java:171)
    at org.datanucleus.metadata.MetaDataManager.loadAnnotationsForClass(MetaDataManager.java:2650)
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:496)
    at org.datanucleus.enhancer.DataNucleusEnhancer.getFileMetadataForInput(DataNucleusEnhancer.java:734)
    at org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:525)
    at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1258)
DataNucleus Enhancer completed with an error. Please review the enhancer log for full details. Some classes may have been enhanced but some caused errors

增强类的来源如下：

@PersistenceCapable(detachable = "true")
public class Record implements Serializable, Cacheable<String> {

    private static final long serialVersionUID = 9022509306966814904L;

    @PrimaryKey
    @Persistent(defaultFetchGroup = "true", valueStrategy = IdGeneratorStrategy.IDENTITY)
    private String id;

    @Name
    @Persistent(defaultFetchGroup = "true")
    private String name;

    @Name
    @Persistent(defaultFetchGroup = "true")
    private String surname;

    @Persistent(defaultFetchGroup = "true")
    private Date dateOfBirth;

    @Persistent(defaultFetchGroup = "true")
    private Date dateRecorded;

    @Persistent(defaultFetchGroup = "true")
    private String locationId;

    @Persistent(embedded = "true", defaultFetchGroup = "true")
    private CustomLocation customLocation;

    @Persistent(defaultFetchGroup = "true")
    private Category category;

    @Persistent(embedded = "true", defaultFetchGroup = "true")
    private CustomCategory customCategory;

    @Persistent(defaultFetchGroup = "true")
    private String description;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private List<StoredImageInfo> images;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private List<StoredAudioInfo> audio;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private List<StoredFileInfo> files;

    @Persistent(defaultFetchGroup = "true")
    private ModerationMode moderationMode;

    @Persistent(defaultFetchGroup = "true")
    private VisibilityMode visibilityMode;

    @Persistent(embedded = "true", defaultFetchGroup = "true")
    private UserProfileSummary owner;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private Map<String, UserProfileSummary> editors;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private Map<String, UserProfileSummary> connections;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private Map<String, RecordSummary> recordConnections;

    @Persistent(defaultFetchGroup = "true")
    private RecordType type;

    @Persistent(defaultFetchGroup = "true")
    private Date expiry;

    public Record() {
    }

    public Record(Record copy) {
        deepCopy(copy);
    }

    ...
}


@PersistenceCapable(embeddedOnly = "true")
public class RecordSummary implements Serializable {

    private static final long serialVersionUID = 9024309306966814904L;

    @Persistent(defaultFetchGroup = "true")
    private String id;

    @Persistent(defaultFetchGroup = "true")
    private RecordRole role;

    @Persistent(defaultFetchGroup = "true")
    private String name;

    @Persistent(defaultFetchGroup = "true")
    private String surname;

    @Persistent(defaultFetchGroup = "true")
    private Date dateOfBirth;

    @Persistent(defaultFetchGroup = "true")
    private Date dateRecorded;

    @SuppressWarnings("unused")
    private RecordSummary() {
        // for serialization
    }

    ...
}


@PersistenceCapable(detachable = "true")
public class Comment implements Attachable<String>, Serializable {

    private static final long serialVersionUID = -7624377549524333808L;

    @PrimaryKey
    @Persistent(defaultFetchGroup = "true", valueStrategy = IdGeneratorStrategy.IDENTITY)
    private String id;

    @Persistent(defaultFetchGroup = "true")
    private String recordId;

    @Persistent(defaultFetchGroup = "true")
    private String username;

    @Persistent(defaultFetchGroup = "true")
    private Date date;

    @Persistent(defaultFetchGroup = "true")
    private String content;

    @SuppressWarnings("unused")
    private Comment() {
        // for serialization
    }

    ...
}

datanucleus 增强器 3.0-release 没有出现任何此类异常（尽管 3.0 存在其他问题：problem 1、problem 2）。 这是 DataNucleus 3.1 的错误还是我做错了什么？

更新：DataNucleus Enhancer 为所有标有@Persistent(embeddedElement = "true") 的列表字段抛出NullPointerException。这很可能是 DataNucleus 3.1 Enhancer 的错误。

更新 2：根据要求，我将包含重现问题的最少代码：

@PersistenceCapable(detachable = "true")
public class Record {

    @PrimaryKey
    @Persistent(defaultFetchGroup = "true", valueStrategy = IdGeneratorStrategy.IDENTITY)
    private String id;

    @Persistent(embeddedElement = "true", defaultFetchGroup = "true")
    private List<MyEmbeddedElement> aList;

    public Record() {
    }

}


@PersistenceCapable(embeddedOnly = "true")
public class MyEmbeddedElement {

    @Persistent
    private String myField;

}

错误：

 730  [main] DEBUG DataNucleus.MetaData  - Class "com.myproject.domain.Record" has been specified with JDO annotations so using those.
 760  [main] DEBUG DataNucleus.MetaData  - Class "com.myproject.domain.MyEmbeddedElement" has been specified with JDO annotations so using those.
 Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
763  [main] ERROR DataNucleus.Enhancer  - DataNucleus Enhancer completed with an error. Please review the enhancer log for full details. Some classes may have been enhanced but some caused errors
 Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
org.datanucleus.exceptions.NucleusUserException: Errors were encountered when loading the specified MetaData files and classes. See the nested exceptions for details
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:536)
    at org.datanucleus.enhancer.DataNucleusEnhancer.getFileMetadataForInput(DataNucleusEnhancer.java:734)
    at org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:525)
    at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1258)
Caused by: java.lang.NullPointerException
    at org.datanucleus.api.jdo.metadata.JDOAnnotationReader.processMemberAnnotations(JDOAnnotationReader.java:1682)
    at org.datanucleus.metadata.annotations.AbstractAnnotationReader.getMetaDataForClass(AbstractAnnotationReader.java:206)
    at org.datanucleus.metadata.annotations.AnnotationManagerImpl.getMetaDataForClass(AnnotationManagerImpl.java:171)
    at org.datanucleus.metadata.MetaDataManager.loadAnnotationsForClass(MetaDataManager.java:2650)
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:496)
    ... 3 more
Nested Throwables StackTrace:
java.lang.NullPointerException
    at org.datanucleus.api.jdo.metadata.JDOAnnotationReader.processMemberAnnotations(JDOAnnotationReader.java:1682)
    at org.datanucleus.metadata.annotations.AbstractAnnotationReader.getMetaDataForClass(AbstractAnnotationReader.java:206)
    at org.datanucleus.metadata.annotations.AnnotationManagerImpl.getMetaDataForClass(AnnotationManagerImpl.java:171)
    at org.datanucleus.metadata.MetaDataManager.loadAnnotationsForClass(MetaDataManager.java:2650)
    at org.datanucleus.metadata.MetaDataManager.loadClasses(MetaDataManager.java:496)
    at org.datanucleus.enhancer.DataNucleusEnhancer.getFileMetadataForInput(DataNucleusEnhancer.java:734)
    at org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:525)
    at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1258)
DataNucleus Enhancer completed with an error. Please review the enhancer log for full details. Some classes may have been enhanced but some caused errors

更新 3：从 3.0.2 开始的所有 DataNucleus 版本中都存在此问题。

【问题讨论】：

我在使用 v3.1 时没有任何问题，并且在我的应用程序中到处都使用嵌入式关系。也许您应该将您的课程减少到最少，只需要一些导致问题的字段

标签： java dos jdo datanucleus

【解决方案1】：

当我在我的应用程序中执行嵌入式集合时，我会这样做

@Element(embedded="true")
Collection<OtherType> myCollField;

这对我有用，并且看起来更合乎逻辑的方式来指定嵌入元素。

还有你的地图字段是错误的......地图没有“元素”，它有“键”和“值”

【讨论】：

使用@Element(embedded="true") 会导致增强器给出"Field "com.MyClass.[collectionField]" is a collection with elements of type "java.util.Collection" yet has been specified as the element being embedded. Your embedded type must be PersistenceCapable" 错误（即使嵌入类型是String）实际上，我开始使用embeddedKey 和embeddedValue 用于映射DataNucleus 3.0，但失败（不记得错误），而使用 embeddedElement 为 Maps 工作。
我对此进行了更多测试，Maps 工作正常，但其增强器对embeddedElement 的处理放置在List 类型的字段上，导致@987654332 @
显然“OtherType”必须是 PersistenceCapable ......因为你说嵌入它。我的嵌入式类是可持久的，所以我也不例外。正如已经说过的那样，地图没有元素，所以元数据是错误的......所以也许 DataNucleus 会忽略你不正确的元数据。
另一种类型是 PersistenceCapable；请注意，我已经写过即使使用字符串列表，结果也是相同的。与 Maps 相同：就 JDO 而言，使用 EmbeddedElement 可能是错误的，但是当 EmbeddedValue 用于 Map 并与 EmbeddedElement 一起使用时，DataNucleus 会失败，这就是我使用 EmbeddedElement 的原因。
你有 List 这与“embeddedElement”无关。如前所述，当字段是 PersistenceCapable 对象的集合时使用“embeddedElement”。