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From Yin Lou <yin.lou...@gmail.com>
Subject Re: Initialize Map class
Date Sun, 17 Oct 2010 19:20:55 GMT
You can use this,
public class WordCount {

    public static class Map extends MapReduceBase implements
            Mapper<LongWritable, Text, Text, IntWritable> {

        public void configure(JobConf job) {
             // put your initialization here
        }

        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();
        private String filename;
        private boolean fopen=false;
        private FSDataOutputStream dos;
        public Map(String fname) {
        .......
        .......
        }
...............
...............
...............
[/code]


On Sun, Oct 17, 2010 at 3:01 PM, web service <wbsrvc@gmail.com> wrote:

> Ok. a bit confused...Noob days.
>
> Did you mean using this method call  -  public *JobConf*(Configuration<http://hadoop.apache.org/common/docs/r0.17.0/api/org/apache/hadoop/conf/Configuration.html>
conf,
> Class <http://java.sun.com/j2se/1.5/docs/api/java/lang/Class.html>
>  exampleClass)
> to initialize the Map class ?
>
> So for example, how would I invoke constructor to the below class ?
>
> [code]
> public class WordCount {
>
>     public static class Map extends MapReduceBase implements
>             Mapper<LongWritable, Text, Text, IntWritable> {
>         private final static IntWritable one = new IntWritable(1);
>         private Text word = new Text();
>         private String filename;
>         private boolean fopen=false;
>         private FSDataOutputStream dos;
>         public Map(String fname) {
>         .......
>         .......
>         }
> ...............
> ...............
> ...............
> [/code]
>
>
>
> On Sun, Oct 17, 2010 at 12:38 PM, Owen O'Malley <omalley@apache.org>wrote:
>
>>
>> On Oct 17, 2010, at 11:31 AM, web service wrote:
>>
>>  I would want to initialize a Map class with some parameters. How do I do
>>> that ?
>>>
>>
>> The objects that define a MapReduce job are all configured by the job's
>> configuration, which is a string to string map. If your Mapper class
>> implements Configurable, it will be initialized with the job's configuration
>> automatically.
>>
>> -- Owen
>>
>
>

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