无法保存带有Map的Objectify实体在嵌入类中？

huangapple
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英文:

Unable to Save Objectify entity with Map<string,Object> in Embedded classes?

问题

我有一个嵌入式实体，其中有一个类型为Map<String, Object>的字段。

地图的所有键都是字符串类型。

以下是实体：

  1. @Entity
  2. @Index
  3. @Getter @Setter
  4. public class NiftySurveys {
  5. 	@Id
  6. 	private Long id;
  7. 	private List&lt;SurveyQuestions&gt; questions;
  8. 	private Long createddate;
  9. 	private Long updatedDate;
  10. }
  12. @Getter @Setter
  13. public class SurveyQuestions {
  14. 	private String label;
  15. 	private String code;
  16. 	private SurveyQuestionGroups questionGroup;
  17. 	private Map&lt;String,Object&gt; optionGroup;
  18. }

我在保存带有optionGroup的实体时遇到问题。

从前端提交的示例实体：

  1. {
  2. 	"questions": [{
  3. 		"label": "jio",
  4. 		"code": null,
  5. 		"questionGroup": {
  6. 			"name": "Date Time",
  7. 			"value": "DATI"
  8. 		},
  9. 		"optionGroup": {
  10. 			"labels": [{
  11. 				"label": "Date / Time"
  12. 			}],
  13. 			"collectDateInfo": true,
  14. 			"collectTimeInfo": true,
  15. 			"dateFormat": "MM/DD/YYYY",
  16. 			"validationMessage": "Please Enter a Valid Date!"
  17. 		}
  18. 	}, {
  19. 		"code": null,
  20. 		"label": "Q2",
  21. 		"questionGroup": {
  22. 			"name": "Multiple Choice Questions",
  23. 			"value": "MCQ"
  24. 		},
  25. 		"optionGroup": {
  26. 			"name": "Agree - Disagree",
  27. 			"code": "AGDAG",
  28. 			"options": [{
  29. 				"label": "YES",
  30. 				"value": "Y"
  31. 			}, {
  32. 				"label": "NO",
  33. 				"value": "N"
  34. 			}]
  35. 		}
  36. 	}]
  37. }

地图的所有键都是字符串类型。

错误消息：

  1. exception: "com.googlecode.objectify.SaveException"
  2. message: "Error saving com.nifty.niftyfeedbacks.domain.NiftySurveys@4ac88d5e: java.lang.IllegalStateException: Embedded Map keys must be of type String/Enum/Key&lt;?&gt; or field must specify @Stringify"

Stack Trace链接：
https://drive.google.com/file/d/1fqpPLiJutWLif5GnrlqLEZ6Wr_PdLdC-/view?usp=sharing

英文:

I have an embedded entity that has a Field of type Map<String, Object>.

All keys to the Map Are of type String.

Below is Entity

  1. @Entity
  2. @Index
  3. @Getter @Setter
  4. public class NiftySurveys {
  5. 	@Id
  6. 	private Long id;
  7. 	private List&lt;SurveyQuestions&gt; questions;
  8. 	private Long createddate;
  9. 	private Long updatedDate;
  10. }
  12. @Getter @Setter
  13. public class SurveyQuestions {
  14. 	private String label;
  15. 	private String code;
  16. 	private SurveyQuestionGroups questionGroup;
  17. 	private Map&lt;String,Object&gt; optionGroup;
  18. }

>I am having trouble saving Entity with optionGroup.

Sample Entity submitted From FrontEnd

  1. {
  2. 	&quot;questions&quot;: [{
  3. 		&quot;label&quot;: &quot;jio&quot;,
  4. 		&quot;code&quot;: null,
  5. 		&quot;questionGroup&quot;: {
  6. 			&quot;name&quot;: &quot;Date Time&quot;,
  7. 			&quot;value&quot;: &quot;DATI&quot;
  8. 		},
  9. 		&quot;optionGroup&quot;: {
  10. 			&quot;labels&quot;: [{
  11. 				&quot;label&quot;: &quot;Date / Time&quot;
  12. 			}],
  13. 			&quot;collectDateInfo&quot;: true,
  14. 			&quot;collectTimeInfo&quot;: true,
  15. 			&quot;dateFormat&quot;: &quot;MM/DD/YYYY&quot;,
  16. 			&quot;validationMessage&quot;: &quot;Please Enter a Valid Date!&quot;
  17. 		}
  18. 	}, {
  19. 		&quot;code&quot;: null,
  20. 		&quot;label&quot;: &quot;Q2&quot;,
  21. 		&quot;questionGroup&quot;: {
  22. 			&quot;name&quot;: &quot;Multiple Choice Questions&quot;,
  23. 			&quot;value&quot;: &quot;MCQ&quot;
  24. 		},
  25. 		&quot;optionGroup&quot;: {
  26. 			&quot;name&quot;: &quot;Agree - Disagree&quot;,
  27. 			&quot;code&quot;: &quot;AGDAG&quot;,
  28. 			&quot;options&quot;: [{
  29. 				&quot;label&quot;: &quot;YES&quot;,
  30. 				&quot;value&quot;: &quot;Y&quot;
  31. 			}, {
  32. 				&quot;label&quot;: &quot;NO&quot;,
  33. 				&quot;value&quot;: &quot;N&quot;
  34. 			}]
  35. 		}
  36. 	}]
  37. }

> All Keys of the map Are Strings.

Error Message:

  1. exception: &quot;com.googlecode.objectify.SaveException&quot;
  2. message: &quot;Error saving com.nifty.niftyfeedbacks.domain.NiftySurveys@4ac88d5e: java.lang.IllegalStateException: Embedded Map keys must be of type String/Enum/Key&lt;?&gt; or field must specify @Stringify&quot;

link to Stack Trace
https://drive.google.com/file/d/1fqpPLiJutWLif5GnrlqLEZ6Wr_PdLdC-/view?usp=sharing

答案1

得分: 1

要查看 @Stringify 的工作原理，请参阅 https://github.com/objectify/objectify/wiki/Entities#stringify：

为了在 Maps 中使用非字符串键，您可以指定 @Stringify 注解：

  1. import com.googlecode.objectify.annotation.Entity;
  2. import com.googlecode.objectify.annotation.Id;
  3. import com.googlecode.objectify.annotation.Stringify;
  4. import com.googlecode.objectify.stringifier.Stringifier;
  6. class DateStringifier implements Stringifier<LocalDate> {
  7.     @Override
  8.     public String toString(LocalDate obj) {
  9.         return obj.getString();
  10.     }
  12.     @Override
  13.     public LocalDate fromString(String str) {
  14.         return new LocalDate(str);
  15.     }
  16. }
  18. @Entity
  19. class Car {
  20.     @Id Long id;
  21.     @Stringify(DateStringifier.class)
  22.     Map<LocalDate, ServiceRecord> serviceHistory = new HashMap<>();
  23. }
英文:

To see how @Stringify works, look at https://github.com/objectify/objectify/wiki/Entities#stringify :

  1. In order to use non-String keys with Maps, you may specify the @Stringify annotation:
  3. import com.googlecode.objectify.annotation.Entity;
  4. import com.googlecode.objectify.annotation.Id;
  5. import com.googlecode.objectify.annotation.Stringify;
  6. import com.googlecode.objectify.stringifier.Stringifier;
  8. class DateStringifier implements Stringifier&lt;LocalDate&gt; {
  9.     @Override
  10.     public String toString(LocalDate obj) {
  11.         return obj.getString();
  12.     }
  14.     @Override
  15.     public LocalDate fromString(String str) {
  16.         return new LocalDate(str);
  17.     }
  18. }
  20. @Entity
  21. class Car {
  22.     @Id Long id;
  23.     @Stringify(DateStringifier.class)
  24.     Map&lt;LocalDate, ServiceRecord&gt; serviceHistory = new HashMap&lt;&gt;();
  25. }

Previous response :
The error message is clear : you must provide a "String-way" to handle your embedded entity. So you should write a toString() method inside your embedded entity or use the @Stringify annotation as appropriate.

It seems to be JSON, so did you try to use @JsonUnwrapped :
@see https://stackoverflow.com/a/10077262/390462

  1. class Item {
  2.     private String title;
  4.     @JsonProperty(&quot;date&quot;)
  5.     private Date createdAt;
  7.     // How to map this?
  8.     @JsonUnwrapped
  9.     private Author author;
  10. }

You can go through a good JPA tutorial to handle Embedded objects too :

  1. https://examples.javacodegeeks.com/enterprise-java/jpa/jpa-embedded-embeddable-example/
  2. https://www.logicbig.com/tutorials/java-ee-tutorial/jpa/embeddable-classes.html
  3. https://www.tutorialspoint.com/ejb/ejb_embeddable_objects.htm

答案2

得分: 0

使用@Serialize注解来处理复杂对象图。
来自Objectify文档

这解决了我的问题。

  1. @Getter @Setter
  2. public class SurveyQuestions implements Serializable{
  3. 	private static final long serialVersionUID = -6930992373082651231L;
  4. 	@Serialize
  5. 	private Map&lt;String,Object&gt; optionGroup;
  6. 	
  7. 	
  8. }
英文:

> Use @Serialize annotation for complex object graph.
From Objectify Docs

This Solved my issue.

  1. @Getter @Setter
  2. public class SurveyQuestions implements Serializable{
  3. 	private static final long serialVersionUID = -6930992373082651231L;
  4. 	@Serialize
  5. 	private Map&lt;String,Object&gt; optionGroup;
  6. 	
  7. 	
  8. }

huangapple
  • 本文由 发表于 2020年8月10日 17:54:55
  • 转载请务必保留本文链接：https://go.coder-hub.com/63337944.html
  • google-cloud-datastore
  • java
  • objectify
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