【发布时间】:2015-01-04 15:16:21
【问题描述】:
我正在使用 hadoop,需要从 /src 文件中的所有类组合创建一个 .jar 文件。每次我尝试创建它时,它都会出现在 WordCount.jar 而不是 Twitter.jar 下,我在下面的代码中已经说过:
import java.util.Arrays;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
public class Twitter {
public static void runJob(String[] input, String output) throws Exception {
Configuration conf = new Configuration();
Job job = new Job(conf);
job.setJarByClass(Twitter.class);
job.setReducerClass(TwitterReducer.class);
job.setMapperClass(TwitterMapper.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(NullWritable.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(NullWritable.class);
Path outputPath = new Path(output);
FileInputFormat.setInputPaths(job, StringUtils.join(input, ","));
FileOutputFormat.setOutputPath(job, outputPath);
outputPath.getFileSystem(conf).delete(outputPath, true);
job.waitForCompletion(true);
}
public static void main(String[] args) throws Exception {
runJob(Arrays.copyOfRange(args, 0, args.length - 1), args[args.length - 1]);
}
}
【问题讨论】:
-
你的类被称为
Twitter但这并不意味着你的.jar必须有这个名字....jar名字可能是在build.xml的jar 创建任务中定义的.可以分享一下吗?
标签: java hadoop ant jar build.xml