下列代码中WordCount是怎样执行的？

下列代码中WordCount是怎样执行的？

public class WordCount{
public static class TokenizerMapper
extends Mapper<ObjectTextTextIntWritable>{
private final static IntWritable one=new IntWritable(1) 
private Text word = new Text();
public void map(Object keyText value, Context context
)throws IOException,InterruptedException{
StringTokenizer itr=new StringTokenizer(valuetoString()) 
while(itr.hasMoreTokens()){ 
word.set(itrnextToken()); 
context.write(word,one);
}
}