mongodb 从文件加载到Mongo集合时，BSON字段名$oid无效

soat7uwm  于 2023-03-17  发布在  Go
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我正在尝试为MongoDb集合编写一个基本的加载程序，它将从文件中读取准备好的文档并将它们插入到集合中。我使用的类目前编写如下：

package com.example;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.apache.commons.io.FileUtils;
import org.bson.Document;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.gson.Gson;
import com.mongodb.BasicDBObject;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.IndexOptions;

public class Example {

    public static void main(String[] args){
        MongoCollection<Document> collection;
        ObjectMapper objectMapper;
        Document[] docArray;
        List<Document> docList;

        //Get the collection from the command line input and drop
        collection = MongoClients.create("mongodb://example:password@localhost:27017/?authSource=admin").getCollection("Example");
        String docListStr;
        try {
            String resourceFilePath = "C:\\sampledata\\example.json";
            File sourceFile = new File(resourceFilePath);
            
            if (!sourceFile.exists()) {
                throw new IllegalArgumentException(String.format("The source file '%s' does not exist.", new Object[] { resourceFilePath }));
            }
            docListStr = FileUtils.readFileToString(sourceFile, StandardCharsets.UTF_8);
            
            objectMapper = new ObjectMapper();
            objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
            docArray = objectMapper.readValue(docListStr, Document[].class);
            docList = new ArrayList<>();
            for (int i=0; i<docArray.length; i++) {
                docList.add(docArray[i]);
            }

            collection.insertMany(docList);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

如果我不指定对象ID（会按预期生成一个），这可以正常工作，但我希望能够清理这个集合，并重新插入具有与之前相同ID的文档。在JSON文件中，我将对象ID与其他数据字段一起指定，如下所示：

[{
    "_id": {
        "$oid": "63df25a1343a3278747d6398"
    },
    "example": "test1",
    "_class": "com.example.Example"
},
{
    "_id": {
        "$oid": "63df25a1343a3278747d6398"
    },
    "example": "test2",
    "_class": "com.example.Example"
}]

然而，当我运行这个程序时，我遇到了下面的错误：

java.lang.IllegalArgumentException: Invalid BSON field name $oid
    at org.bson.AbstractBsonWriter.writeName(AbstractBsonWriter.java:532)
    at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:198)
    at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:182)
    at org.bson.codecs.DocumentCodec.beforeFields(DocumentCodec.java:167)
    at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:192)
    at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:141)
    at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:45)
    at org.bson.codecs.BsonDocumentWrapperCodec.encode(BsonDocumentWrapperCodec.java:63)
    at org.bson.codecs.BsonDocumentWrapperCodec.encode(BsonDocumentWrapperCodec.java:29)
    at com.mongodb.operation.BulkWriteBatch$WriteRequestEncoder.encode(BulkWriteBatch.java:387)
    at com.mongodb.operation.BulkWriteBatch$WriteRequestEncoder.encode(BulkWriteBatch.java:377)
    at org.bson.codecs.BsonDocumentWrapperCodec.encode(BsonDocumentWrapperCodec.java:63)
    at org.bson.codecs.BsonDocumentWrapperCodec.encode(BsonDocumentWrapperCodec.java:29)
    at com.mongodb.internal.connection.BsonWriterHelper.writeDocument(BsonWriterHelper.java:75)
    at com.mongodb.internal.connection.BsonWriterHelper.writePayload(BsonWriterHelper.java:59)
    at com.mongodb.internal.connection.CommandMessage.encodeMessageBodyWithMetadata(CommandMessage.java:143)
    at com.mongodb.internal.connection.RequestMessage.encode(RequestMessage.java:138)
    at com.mongodb.internal.connection.CommandMessage.encode(CommandMessage.java:57)
    at com.mongodb.internal.connection.InternalStreamConnection.sendAndReceive(InternalStreamConnection.java:244)
    at com.mongodb.internal.connection.UsageTrackingInternalConnection.sendAndReceive(UsageTrackingInternalConnection.java:99)
    at com.mongodb.internal.connection.DefaultConnectionPool$PooledConnection.sendAndReceive(DefaultConnectionPool.java:444)
    at com.mongodb.internal.connection.CommandProtocolImpl.execute(CommandProtocolImpl.java:72)
    at com.mongodb.internal.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:200)
    at com.mongodb.internal.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:269)
    at com.mongodb.internal.connection.DefaultServerConnection.command(DefaultServerConnection.java:131)
    at com.mongodb.operation.MixedBulkWriteOperation.executeCommand(MixedBulkWriteOperation.java:419)
    at com.mongodb.operation.MixedBulkWriteOperation.executeBulkWriteBatch(MixedBulkWriteOperation.java:257)
    at com.mongodb.operation.MixedBulkWriteOperation.access$700(MixedBulkWriteOperation.java:68)
    at com.mongodb.operation.MixedBulkWriteOperation$1.call(MixedBulkWriteOperation.java:201)
    at com.mongodb.operation.MixedBulkWriteOperation$1.call(MixedBulkWriteOperation.java:192)
    at com.mongodb.operation.OperationHelper.withReleasableConnection(OperationHelper.java:424)
    at com.mongodb.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:192)
    at com.mongodb.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:67)
    at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:193)
    at com.mongodb.client.internal.MongoCollectionImpl.executeInsertMany(MongoCollectionImpl.java:520)
    at com.mongodb.client.internal.MongoCollectionImpl.insertMany(MongoCollectionImpl.java:504)
    at com.mongodb.client.internal.MongoCollectionImpl.insertMany(MongoCollectionImpl.java:499)

如何解决此问题以允许在文件中指定对象ID？
更新：
我目前有一个变通方法，就是检查列表中每个Document的键集，如果它匹配“_id”，则获取相应的值，将其解析为字符串以获取$oid属性并转换为ObjectId。然后删除现有的“_id”键-值对，并将其添加回ObjectId类型：

for (Document docListEntry: docList) {
        if (docListEntry.get("_id") != null) {
            ObjectId objectId = new ObjectId(docListEntry.remove("_id").toString().split("}")[0].split("=")[1]);
            docListEntry.put("_id",objectId);   
        }
}

不是很干净，但暂时解决了我的问题

mongodb

1条答案

按热度按时间
j2datikz

j2datikz1#

你可以升级你的mongo驱动版本。我用下面的版本工作正常。

<!-- https://mvnrepository.com/artifact/org.mongodb/mongo-java-driver -->
<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongo-java-driver</artifactId>
    <version>3.12.12</version>
</dependency>

你也可以使用下面的代码来获取文档列表更容易.

CollectionType collectionType = objectMapper.getTypeFactory().constructCollectionType(ArrayList.class, Document.class);
List<Document> docList = objectMapper.readValue(docListStr, collectionType);

EDIT：添加$后，可以使用Document.parse代替objectMapper.readValue，如下所示。

package com.example;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.CollectionType;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import org.apache.commons.io.FileUtils;
import org.bson.Document;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;

public class Example {

    public static void main(String[] args) {
        MongoCollection<Document> collection;
        ObjectMapper objectMapper;

        //Get the collection from the command line input and drop
        MongoClient mongoClient = MongoClients.create("mongodb+srv://co:co@cluster0.tx0sb.mongodb.net/?retryWrites=true&w=majority");
        collection = mongoClient.getDatabase("a").getCollection("Example");
        String docListStr;
        try {
            String resourceFilePath = "C:\\sampledata\\example.json";
            File sourceFile = new File(resourceFilePath);

            if (!sourceFile.exists()) {
                throw new IllegalArgumentException(String.format("The source file '%s' does not exist.", resourceFilePath));
            }
            docListStr = FileUtils.readFileToString(sourceFile, StandardCharsets.UTF_8);

            objectMapper = new ObjectMapper();
            objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
            TypeFactory typeFactory = objectMapper.getTypeFactory();
            CollectionType collectionType = typeFactory.constructCollectionType(ArrayList.class, typeFactory.constructMapType(LinkedHashMap.class, String.class, Object.class));
            List<LinkedHashMap<String, Object>> mapList = objectMapper.readValue(docListStr, collectionType);

            List<Document> docList = new ArrayList<>(mapList.size());
            for (LinkedHashMap<String, Object> map : mapList) {
                String docStr = objectMapper.writeValueAsString(map);
                Document document = Document.parse(docStr);
                docList.add(document);
            }
            collection.insertMany(docList);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}
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