Question

我在mongodb数据库中有以下gridfs：

db.outputFs.files.find()

{ "_id" : ObjectId("000000000000000000000001"), "chunkSize" : 261120, "length" : 232, "md5" : "42290309186cc5420acff293b92ae21d", "filename" : "/tmp/outputFs-01.tmp", "contentType" : null, "uploadDate" : ISODate("2015-04-13T13:50:48.259Z"), "aliases" : null, "metadata" : { "estado" : "FICHERO_PDTE_ENVIO", "dataDate" : "20141122", "inputOutputFs" : "output", "gridFileCompression" : "bzip2", "fileType" : "OUTPUT-TEST1", "filePath" : "/tmp/outputFs-01.tmp", "sourceParticipant" : "0100", "destinationParticipant" : "REE", "exportFileName" : "F1_0100_20141122_20150219.0", "processed" : "false", "fileMD5" : "4276e61a4b63d3d1d1b77e27e792bd13", "version" : 0 } }

{ "_id" : ObjectId("000000000000000000000002"), "chunkSize" : 261120, "length" : 232, "md5" : "42290309186cc5420acff293b92ae21d", "filename" : "/tmp/outputFs-02.tmp", "contentType" : null, "uploadDate" : ISODate("2015-04-13T13:50:48.259Z"), "aliases" : null, "metadata" : { "estado" : "FICHERO_ENVIADO_OK", "fechaEnvio" : ISODate("2015-04-13T13:50:48.259Z"), "dataDate" : "20141123", "inputOutputFs" : "output", "gridFileCompression" : "bzip2", "fileType" : "OUTPUT-TEST2", "filePath" : "/tmp/outputFs-02.tmp", "sourceParticipant" : "0100", "destinationParticipant" : "REE", "exportFileName" : "F1_0100_20141123_20150220.0", "processed" : "false", "fileMD5" : "4276e61a4b63d3d1d1b77e27e792bd13", "version" : 0 } }



db.outputFs.chunks.find()

{ "_id" : ObjectId("000000000000000000000001"), "files_id" :  ObjectId("000000000000000000000001"), "n" : 0, "data" : { "$type" : 0, "$binary" : "QlpoOTFBWSZTWZSBQ/YABX5cAAAYQAH/+CAAMAFWA0NqptIb9UgAZ6qowAAFKSaJpGhk8ssmVlk7AAAALZtZZOf0vr859OqflcIs461Dm1skcSOpGpHMuu5HcsJG0j5I9PiR4kaRvvjWskfsVMkZVLxI3uRy/pGTqRj7VmMyTOBfUtb561rwkf0j09+Zbkd+cs1I77861xI7pypvfOt1v5DmR1I51nW7XGdaluRnGZjMzJMzOZGpHnrfGM56+/fnGPVVVVVqqpVVWxCSxCTSAEMkZI3IyqXuqXyRuR/i7kinChISkCh+wA==" } }

{ "_id" : ObjectId("000000000000000000000002"), "files_id" : ObjectId("000000000000000000000002"), "n" : 0, "data" : { "$type" : 0, "$binary" : "QlpoOTFBWSZTWZSBQ/YABX5cAAAYQAH/+CAAMAFWA0NqptIb9UgAZ6qowAAFKSaJpGhk8ssmVlk7AAAALZtZZOf0vr859OqflcIs461Dm1skcSOpGpHMuu5HcsJG0j5I9PiR4kaRvvjWskfsVMkZVLxI3uRy/pGTqRj7VmMyTOBfUtb561rwkf0j09+Zbkd+cs1I77861xI7pypvfOt1v5DmR1I51nW7XGdaluRnGZjMzJMzOZGpHnrfGM56+/fnGPVVVVVqqpVVWxCSxCTSAEMkZI3IyqXuqXyRuR/i7kinChISkCh+wA==" } }

当我尝试使用Spring Data甚至MongoChef（两个Java客户端）作为文件检索它时，收到以下错误：

com.mongodb.BasicDBObject cannot be cast to [B

系列是按原样手动导入的，而不是使用MongoChef或mongofiles，我不知道此错误可能来自哪里。

Answer 1

GridFS规范要求Binary集合中名为data的{{1}}字段。但是，您的chunks不符合此标准。

此处的outputFs.chunks字段不是data BSON数据类型，而是一个恰好有两个字段Binary和$type的常规文档。

$data将仅为以下格式的JSON条目创建二进制字段。请注意，字段的顺序对mongoimport很重要。

mongoimport

您的示例已交换{ "$binary" : ... "$type" : ... }和$type个字段。

更新您的JSON文件并再次导入$binary。 outputFs.chunks将创建有效的二进制字段，您将能够使用其他MongoDB工具使用GridFS。

无法将BasicDBObject强制转换为[B

1 个答案: