com.aliyun.odps.io

Interface OutputBlobWritable

All Superinterfaces:

Comparable, Writable, WritableComparable

public interface OutputBlobWritable
extends WritableComparable

OutputBlobWritable表示ODPS表或分区中列类型为blob的输出接口, 该接口只能用于 com.aliyun.odps.mapreduce.Reducer向 com.aliyun.odps.Record 中写入blob类型的列.

用法示例：

 @Override
 public void reduce(KEYIN key, Iterable<VALUEIN> values,
     MapContext<KEYIN, VALUEIN> context) throws IOException {
   Record outputRecord = context.createOutputRecord();
   OutputBlobWritable blob = outputRecord.get(0);
   BufferedOutputStream out = blob.getOutputStream();
   // 使用out.write向blob中写入数据
   out.close();
 }
 

从上面的示例看出, 从com.aliyun.odps.Record获得OutputBlobWritable接口, 调用OutputBlobWritable的 getOutputStream获得BufferedOutputStream后，即可进行写入数据.

Method Summary

Modifier and Type	Method and Description
BufferedOutputStream	getOutputStream() getOutputStream方法获取可以写入blob的BufferedOutputStream接口

Methods inherited from interface com.aliyun.odps.io.Writable

readFields, write

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

getOutputStream

BufferedOutputStream getOutputStream()
                              throws IOException

getOutputStream方法获取可以写入blob的BufferedOutputStream接口

Returns:

blob列对应的BufferedOutputStream

Throws:

IOException