提供将 mongodb
聚合管道 Json
转为 mongo java
客户端需要的 Bson
格式。
一般可以配合 DataX
插件 mongodbpipelineReader
使用。插件地址:
对应 mongo-java-driver
版本:3.10.2
使用非常简单,仅仅需要增加一个 pom
依赖,然后通过 MongoDBPipelineUtils.aggregateJson2BsonList(json)
转换即可。
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.pipeline.transfer.MongoDBPipelineUtils;
...
String aggregate = "[{ $match : { Date:{$gte:\"20181112\", $lt:\"2018113\" }}},{ $lookup : { from: \"FeeInfo\", " +
"localField: \"FeeVourcherID\", foreignField: \"FeeVourcherID\", as: \"fee\" }}...]";
List<Bson> bsonList = MongoDBPipelineUtils.aggregateJson2BsonList(aggregate);
MongoCursor<Document> dbCursor = col.aggregate(bsonList).allowDiskUse(true).iterator();
将 MongoDB pipeline
字符串解析为 List<Bson>
进行聚合操作。
[{
$match : {
Date:{$gte:"20181112", $lt:"2018113" }
}
},{
$lookup : {
from: "FeeInfo",
localField: "FeeVourcherID",
foreignField: "FeeVourcherID",
as: "fee"
}
},{
$unwind :{ path:"$fee", preserveNullAndEmptyArrays: true}
},{
$project: {
SystemNo: "$SystemNo",
Date: "$TxDate",
Income: { $ifNull: [ "$fee.Income", "$Income" ] },
IncomeStatus: {$cond: {if: {$gte: ["$fee.Income", NumberInt("0")]},
then: "$fee.IncomeStatus", else: NumberInt("40")}}
}
},{
$addFields: {
Status: NumberInt("0")
}
}]
以上字符串将会被解析为
List<Bson> bsonList = new ArrayList<>();
bsonList.add(Aggregates.match(Filters.and(Filters.gte("Date", "20181112"),
Filters.lt("Date", "2018113"))));
bsonList.add(Aggregates.lookup("FeeInfo", "FeeVourcherID", "FeeVourcherID", "fee"));
bsonList.add(Aggregates.unwind("$fee", new UnwindOptions().preserveNullAndEmptyArrays(true)));
bsonList.add(Aggregates.project(new Document("SystemNo", "$SystemNo")
.append("Date", "$Date")
.append("Income", new Document("$ifNull", Arrays.asList("$fee.Income", "$Income")))
.append("IncomeStatus", new Document("$cond",
Arrays.asList(new Document("$gte", Arrays.asList("$fee.Income", 0)), "$fee.IncomeStatus", 40)))
));
bsonList.add(Aggregates.addFields(new Field<>("Status", new BsonInt64(Long.parseLong("0")))));
mongo-pipeline-transfer is released under the Apache 2.0 license.
如果你有任何问题,欢迎提Issus,或者通过邮件联系 [email protected]
。