原因：org.bson.codecs.configuration.CodecConfigurationException：找不到类 com.example.Hobbies 的编解码器

Question

如何使用BSONObject 插入嵌入文档？当我尝试插入嵌入文档时，出现如下所示的错误。

例如，我想为 Date 和 firstName 保存空值。我使用 Spring Data Mongo 尝试了一些选项，但效果不佳。

我遇到以下错误：

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:816) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:797) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:324) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at com.example.MongoPocApplication.main(MongoPocApplication.java:24) [classes/:na]
Caused by: org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class com.example.Hobbies.
    at org.bson.codecs.configuration.CodecCache.getOrThrow(CodecCache.java:46) ~[bson-3.8.2.jar:na]
    at org.bson.codecs.configuration.ProvidersCodecRegistry.get(ProvidersCodecRegistry.java:63) ~[bson-3.8.2.jar:na]
    at org.bson.codecs.configuration.ChildCodecRegistry.get(ChildCodecRegistry.java:51) ~[bson-3.8.2.jar:na]
    at com.mongodb.DBObjectCodec.writeValue(DBObjectCodec.java:231) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.DBObjectCodec.encodeIterable(DBObjectCodec.java:292) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.DBObjectCodec.writeValue(DBObjectCodec.java:219) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.DBObjectCodec.encode(DBObjectCodec.java:149) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.DBObjectCodec.encode(DBObjectCodec.java:65) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.BasicDBObject.toJson(BasicDBObject.java:194) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.BasicDBObject.toJson(BasicDBObject.java:167) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.BasicDBObject.toJson(BasicDBObject.java:154) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.BasicDBObject.toString(BasicDBObject.java:238) ~[mongodb-driver-core-3.8.2.jar:na]
    at java.lang.String.valueOf(String.java:2994) ~[na:1.8.0_171]
    at java.io.PrintStream.println(PrintStream.java:821) ~[na:1.8.0_171]
    at com.example.MongoPocApplication.savePersons(MongoPocApplication.java:70) [classes/:na]
    at com.example.MongoPocApplication.run(MongoPocApplication.java:34) [classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:813) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]

Person.java

@Builder
@Data
@AllArgsConstructor
@NoArgsConstructor
@Document
public class Person {
    @Id
    private String id;
    @Field
    private String firstName;
    @Field
    private String lastName;

    @Field
    private String emailId;
    @Field
    private List<Hobbies> hobbies;
}

爱好：

@Builder
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Hobbies {
    private String interest;
    private String sports;
}

主要

BSONObject personBsonObj = BasicDBObjectBuilder.start()
                .add("firstName","John")
                .add("lastName", null)
                .add("email","john.kerr@gmail.com")
                .add("hobbies",Arrays.asList(hobbies1, hobbies2, hobbies4)).get();

        BSONObject insert = mongoTemplate.insert(personBsonObj,"person");
        System.out.println(insert);

Answer 1

我在我的一堂课中发现了同样的问题。问题是您声明的不仅仅是 bean 的构造函数。不知道为什么，以及如何与异常的消息联系起来。

@AllArgsConstructor
@NoArgsConstructor

这里的问题不是 Lombok，而是 Lombok 在你的类中插入了两个构造函数：

public Person(String id, 
              String firstName, 
              String lastName, 
              String emailId,
              List<Hobbies> hobbies) { /* ... */ }

public Person() { /* ... */ }

删除两个构造函数之一，编解码器的问题就会消失。

希望对你有帮助。

Answer 2

我能够解决这个问题，如下所示。我想知道我们是否可以使用 Spring Data Mongo Repository 查询来做到这一点？

Document hobbies1 = new Document();
hobbies1.put("interest", "Indoor");
hobbies1.put("sports", "Chess");

Document hobbies2 = new Document();
hobbies2.put("Loveoor", "Table Tennis");
hobbies2.put("Gamedoor", "Cricket");

BSONObject personBsonObj = BasicDBObjectBuilder.start()
    .add("firstName","John")
    .add("lastName", null)
    .add("email","john.kerr@gmail.com")
    .add("hobbies",Arrays.asList(hobbies1, hobbies2)).get();
BSONObject insert = mongoTemplate.insert(personBsonObj,"person");
    System.out.println(insert);