类 org.apache.hadoop.mapreduce.TaskInputOutputContext
的使用

使用TaskInputOutputContext的程序包

程序包	说明
org.apache.hadoop.mapreduce
org.apache.hadoop.mapreduce.lib.output

org.apache.hadoop.mapreduce中TaskInputOutputContext的使用

org.apache.hadoop.mapreduce中TaskInputOutputContext的子类

限定符和类型	类和说明
class	MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> The context that is given to the Mapper.
class	Mapper.Context
class	ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> The context passed to the Reducer.
class	Reducer.Context

org.apache.hadoop.mapreduce.lib.output中TaskInputOutputContext的使用

参数类型为TaskInputOutputContext的org.apache.hadoop.mapreduce.lib.output中的方法

限定符和类型	方法和说明
static Path	FileOutputFormat.getPathForWorkFile(TaskInputOutputContext<?,?,?,?> context, String name, String extension) Helper function to generate a Path for a file that is unique for the task within the job output directory.
static Path	FileOutputFormat.getWorkOutputPath(TaskInputOutputContext<?,?,?,?> context) Get the Path to the task's temporary output directory for the map-reduce job Tasks' Side-Effect Files Some applications need to create/write-to side-files, which differ from the actual job-outputs.

参数类型为TaskInputOutputContext的org.apache.hadoop.mapreduce.lib.output中的构造器

构造器和说明
MultipleOutputs(TaskInputOutputContext<?,?,KEYOUT,VALUEOUT> context) Creates and initializes multiple outputs support, it should be instantiated in the Mapper/Reducer setup method.