MultipleOutputFormat多文件输出
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 import java.io.IOException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.RecordWriter; import org.apache.hadoop.mapred.lib.MultipleOutputFormat; import org.apache.hadoop.util.Progressable; import org.w3c.dom.Text; public class MultipleOutputFormatTest extends MultipleOutputFormat<Text, IntWritable>{ protected String generateFileNameForKeyValue(Text key, IntWritable value, Configuration conf) { char c = key.toString().toLowerCase().charAt( 0 ); if (c >= 'a' && c <= 'z' ){ return c + ".txt" ; } return "other.txt" ; } @Override protected RecordWriter<Text, IntWritable> getBaseRecordWriter( FileSystem fs, JobConf job, String name, Progressable arg3) throws IOException { // TODO Auto-generated method stub return null ; } } 在教程当中只需要重写generateFileNameForKeyValue就能达到分文件的效果 但是在实践当中 还需要重写另一个方法getBaseRecordWriter还没有清楚其功能 先写着先 conf.setOutputFormat() //通过这个设定我们输出格式 本文转自 拖鞋崽 51CTO博客，原文链接:http://blog.51cto.com/1992mrwang/1206459
