355      阿裏雲

多線程下載示例__SDK示例_批量數據通道_大數據計算服務-阿裏雲

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import com.aliyun.odps.Column;
 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.Record;
 import com.aliyun.odps.data.RecordReader;
 import com.aliyun.odps.tunnel.TableTunnel;
 import com.aliyun.odps.tunnel.TableTunnel.DownloadSession;
 import com.aliyun.odps.tunnel.TunnelException;
 class DownloadThread implements Callable<Long> {
         private long id;
         private RecordReader recordReader;
         private TableSchema tableSchema;
         public DownloadThread(int id,
                         RecordReader recordReader, TableSchema tableSchema) {
                 this.id = id;
                 this.recordReader = recordReader;
                 this.tableSchema = tableSchema;
         }
         @Override
         public Long call() {
                 Long recordNum = 0L;
                 try {
                         Record record;
                         while ((record = recordReader.read()) != null) {
                                 recordNum++;
                                 System.out.print("Thread " + id + "t");
                                 consumeRecord(record, tableSchema);
                         }
                         recordReader.close();
                 } catch (IOException e) {
                         e.printStackTrace();
                 }
                 return recordNum;
         }
         private static void consumeRecord(Record record, TableSchema schema) {
                 for (int i = 0; i < schema.getColumns().size(); i++) {
                         Column column = schema.getColumn(i);
                         String colValue = null;
                         switch (column.getType()) {
                         case BIGINT: {
                                 Long v = record.getBigint(i);
                                 colValue = v == null ? null : v.toString();
                                 break;
                         }
                         case BOOLEAN: {
                                 Boolean v = record.getBoolean(i);
                                 colValue = v == null ? null : v.toString();
                                 break;
                         }
                         case DATETIME: {
                                 Date v = record.getDatetime(i);
                                 colValue = v == null ? null : v.toString();
                                 break;
                         }
                         case DOUBLE: {
                                 Double v = record.getDouble(i);
                                 colValue = v == null ? null : v.toString();
                                 break;
                         }
                         case STRING: {
                                 String v = record.getString(i);
                                 colValue = v == null ? null : v.toString();
                                 break;
                         }
                         default:
                                 throw new RuntimeException("Unknown column type: "
                                                 + column.getType());
                         }
                         System.out.print(colValue == null ? "null" : colValue);
                         if (i != schema.getColumns().size())
                                 System.out.print("t");
                 }
                 System.out.println();
         }
 }
 public class DownloadThreadSample {
         private static String accessId = "<your access id>";
         private static String accessKey = "<your access Key>";
         private static String odpsUrl = "https://service.odps.aliyun.com/api";
         private static String project = "<your project>";
         private static String table = "<your table name>";
         private static String partition = "<your partition spec>";
         private static int threadNum = 10;
         public static void main(String args[]) {
                 Account account = new AliyunAccount(accessId, accessKey);
                 Odps odps = new Odps(account);
                 odps.setEndpoint(odpsUrl);
                 odps.setDefaultProject(project);
                 TableTunnel tunnel = new TableTunnel(odps);
                 PartitionSpec partitionSpec = new PartitionSpec(partition);
                 DownloadSession downloadSession;
                 try {
                         downloadSession = tunnel.createDownloadSession(project, table,
                                         partitionSpec);
                         System.out.println("Session Status is : "
                                         + downloadSession.getStatus().toString());
                         long count = downloadSession.getRecordCount();
                         System.out.println("RecordCount is: " + count);
                         ExecutorService pool = Executors.newFixedThreadPool(threadNum);
                         ArrayList<Callable<Long>> callers = new ArrayList<Callable<Long>>();
                         long start = 0;
                         long step = count / threadNum;
                         for (int i = 0; i < threadNum - 1; i++) {
                                 RecordReader recordReader = downloadSession.openRecordReader(
                                                 step * i, step);
                                 callers.add(new DownloadThread( i, recordReader, downloadSession.getSchema()));
                         }
                         RecordReader recordReader = downloadSession.openRecordReader(step * (threadNum - 1), count
                                         - ((threadNum - 1) * step));
                         callers.add(new DownloadThread( threadNum - 1, recordReader, downloadSession.getSchema()));
                         Long downloadNum = 0L;
                         List<Future<Long>> recordNum = pool.invokeAll(callers);
                         for (Future<Long> num : recordNum)
                                 downloadNum += num.get();
                         System.out.println("Record Count is: " + downloadNum);
                         pool.shutdown();
                 } catch (TunnelException e) {
                         e.printStackTrace();
                 } catch (IOException e) {
                         e.printStackTrace();
                 } catch (InterruptedException e) {
                         e.printStackTrace();
                 } catch (ExecutionException e) {
                         e.printStackTrace();
                 }
         }
 }