基于Tunnel SDK如何上傳複雜類型資料到MaxCompute?首先介紹一下MaxCompute複雜資料類型:
複雜資料類型
MaxCompute采用基于ODPS2.0的SQL引擎,豐富了對複雜資料類型類型的支援。MaxCompute支援ARRAY, MAP, STRUCT類型,并且可以任意嵌套使用并提供了配套的内建函數。
類型 | 定義方法 | 構造方法 |
---|---|---|
ARRAY | array;array> | array(1, 2, 3); array(array(1, 2); array(3, 4)) |
MAP | map;map> | map(“k1”, “v1”, “k2”, “v2”);map(1S, array(‘a’, ‘b’), 2S, array(‘x’, ‘y)) |
STRUCT | struct;struct< field1:bigint, field2:array, field3:map> | named_struct(‘x’, 1, ‘y’, 2);named_struct(‘field1’, 100L, ‘field2’, array(1, 2), ‘field3’, map(1, 100, 2, 200) |
複雜類型構造與操作函數
傳回類型 | 簽名 | 注釋 |
---|---|---|
map(K key1, V value1, K key2, V value2, ...) | 使用給定key/value對建立map, 所有key類型一緻,必須是基本類型,所有value類型一緻,可為任意類型 | |
map_keys(Map m) | 将參數中的map的所有key作為數組傳回,輸入NULL,傳回NULL | |
map_values(MAP m) | 将參數中的map的所有value作為數組傳回,輸入NULL,傳回NULL | |
int | size(MAP) | 取得給定MAP元素數目 |
TABLE | explode(MAP) | 表生成函數,将給定MAP展開,每個key/value一行,每行兩列分别對應key和value |
array(T value1, T value2, ...) | 使用給定value構造ARRAY,所有value類型一緻 | |
size(ARRAY) | 取得給定ARRAY元素數目 | |
boolean | array_contains(ARRAY a, value v) | 檢測給定ARRAY a中是否包含v |
sort_array(ARRAY) | 對給定數組排序 | |
collect_list(T col) | 聚合函數,在給定group内,将col指定的表達式聚合為一個數組 | |
collect_set(T col) | 聚合函數,在給定group内,将col指定的表達式聚合為一個無重複元素的集合數組 | |
explode(ARRAY) | 表生成函數,将給定ARRAY展開,每個value一行,每行一列對應相應數組元素 | |
TABLE (int, T) | posexplode(ARRAY) | 表生成函數,将給定ARRAY展開,每個value一行,每行兩列分别對應數組從0開始的下标和數組元素 |
struct(T1 value1, T2 value2, ...) | 使用給定value清單建立struct, 各value可為任意類型,生成struct的field的名稱依次為col1, col2, ... | |
named_struct(name1, value1, name2, value2, ...) | 使用給定name/value清單建立struct, 各value可為任意類型,生成struct的field的名稱依次為name1, name2, ... | |
TABLE (f1 T1, f2 T2, ...) | inline(ARRAY>) | 表生成函數,将給定struct數組展開,每個元素對應一行,每行每個struct元素對應一列 |
Tunnel SDK 介紹
Tunnel 是 ODPS 的資料通道,使用者可以通過 Tunnel 向 ODPS 中上傳或者下載下傳資料。
TableTunnel 是通路 ODPS Tunnel 服務的入口類,僅支援表資料(非視圖)的上傳和下載下傳。
對一張表或 partition 上傳下載下傳的過程,稱為一個session。session 由一或多個到 Tunnel RESTful API 的 HTTP Request 組成。
session 用 session ID 來辨別,session 的逾時時間是24小時,如果大批量資料傳輸導緻超過24小時,需要自行拆分成多個 session。
資料的上傳和下載下傳分别由
TableTunnel.UploadSession
和
TableTunnel.DownloadSession
這兩個會話來負責。
TableTunnel 提供建立 UploadSession 對象和 DownloadSession 對象的方法.
-
典型表資料上傳流程:
1) 建立 TableTunnel
2) 建立 UploadSession
3) 建立 RecordWriter,寫入 Record
4)送出上傳操作
-
典型表資料下載下傳流程:
2) 建立 DownloadSession
3) 建立 RecordReader,讀取 Record
基于Tunnel SDK構造複雜類型資料
代碼示例:
RecordWriter recordWriter = uploadSession.openRecordWriter(0);
ArrayRecord record = (ArrayRecord) uploadSession.newRecord();
// prepare data
List arrayData = Arrays.asList(1, 2, 3);
Map<String, Long> mapData = new HashMap<String, Long>();
mapData.put("a", 1L);
mapData.put("c", 2L);
List<Object> structData = new ArrayList<Object>();
structData.add("Lily");
structData.add(18);
// set data to record
record.setArray(0, arrayData);
record.setMap(1, mapData);
record.setStruct(2, new SimpleStruct((StructTypeInfo) schema.getColumn(2).getTypeInfo(),
structData));
// write the record
recordWriter.write(record);
從MaxCompute下載下傳複雜類型資料
RecordReader recordReader = downloadSession.openRecordReader(0, 1);
// read the record
ArrayRecord record1 = (ArrayRecord)recordReader.read();
// get array field data
List field0 = record1.getArray(0);
List<Long> longField0 = record1.getArray(Long.class, 0);
// get map field data
Map field1 = record1.getMap(1);
Map<String, Long> typedField1 = record1.getMap(String.class, Long.class, 1);
// get struct field data
Struct field2 = record1.getStruct(2);
運作執行個體
完整代碼如下:
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.aliyun.odps.Odps;
import com.aliyun.odps.PartitionSpec;
import com.aliyun.odps.TableSchema;
import com.aliyun.odps.account.Account;
import com.aliyun.odps.account.AliyunAccount;
import com.aliyun.odps.data.ArrayRecord;
import com.aliyun.odps.data.RecordReader;
import com.aliyun.odps.data.RecordWriter;
import com.aliyun.odps.data.SimpleStruct;
import com.aliyun.odps.data.Struct;
import com.aliyun.odps.tunnel.TableTunnel;
import com.aliyun.odps.tunnel.TableTunnel.UploadSession;
import com.aliyun.odps.tunnel.TableTunnel.DownloadSession;
import com.aliyun.odps.tunnel.TunnelException;
import com.aliyun.odps.type.StructTypeInfo;
public class TunnelComplexTypeSample {
private static String accessId = "<your access id>";
private static String accessKey = "<your access Key>";
private static String odpsUrl = "<your odps endpoint>";
private static String project = "<your project>";
private static String table = "<your table name>";
// partitions of a partitioned table, eg: "pt=\'1\',ds=\'2\'"
// if the table is not a partitioned table, do not need it
private static String partition = "<your partition spec>";
public static void main(String args[]) {
Account account = new AliyunAccount(accessId, accessKey);
Odps odps = new Odps(account);
odps.setEndpoint(odpsUrl);
odps.setDefaultProject(project);
try {
TableTunnel tunnel = new TableTunnel(odps);
PartitionSpec partitionSpec = new PartitionSpec(partition);
// ---------- Upload Data ---------------
// create upload session for table
// the table schema is {"col0": ARRAY<BIGINT>, "col1": MAP<STRING, BIGINT>, "col2": STRUCT<name:STRING,age:BIGINT>}
UploadSession uploadSession = tunnel.createUploadSession(project, table, partitionSpec);
// get table schema
TableSchema schema = uploadSession.getSchema();
// open record writer
RecordWriter recordWriter = uploadSession.openRecordWriter(0);
ArrayRecord record = (ArrayRecord) uploadSession.newRecord();
// prepare data
List arrayData = Arrays.asList(1, 2, 3);
Map<String, Long> mapData = new HashMap<String, Long>();
mapData.put("a", 1L);
mapData.put("c", 2L);
List<Object> structData = new ArrayList<Object>();
structData.add("Lily");
structData.add(18);
// set data to record
record.setArray(0, arrayData);
record.setMap(1, mapData);
record.setStruct(2, new SimpleStruct((StructTypeInfo) schema.getColumn(2).getTypeInfo(),
structData));
// write the record
recordWriter.write(record);
// close writer
recordWriter.close();
// commit uploadSession, the upload finish
uploadSession.commit(new Long[]{0L});
System.out.println("upload success!");
// ---------- Download Data ---------------
// create download session for table
// the table schema is {"col0": ARRAY<BIGINT>, "col1": MAP<STRING, BIGINT>, "col2": STRUCT<name:STRING,age:BIGINT>}
DownloadSession downloadSession = tunnel.createDownloadSession(project, table, partitionSpec);
schema = downloadSession.getSchema();
// open record reader, read one record here for example
RecordReader recordReader = downloadSession.openRecordReader(0, 1);
// read the record
ArrayRecord record1 = (ArrayRecord)recordReader.read();
// get array field data
List field0 = record1.getArray(0);
List<Long> longField0 = record1.getArray(Long.class, 0);
// get map field data
Map field1 = record1.getMap(1);
Map<String, Long> typedField1 = record1.getMap(String.class, Long.class, 1);
// get struct field data
Struct field2 = record1.getStruct(2);
System.out.println("download success!");
} catch (TunnelException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
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