package org.nchc.hadoop;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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;
import org.apache.hadoop.util.GenericOptionsParser;
public class HelloHadoopV3 {
public static void main(String[] args) throws IOException,
InterruptedException, ClassNotFoundException {
// eclipse using
// String[] argv = {"/home/hadoop/input","/home/hadoop/output-hh3"};
// args = argv;
String hdfs_input = "HH3_input";
String hdfs_output = "HH3_output";
Configuration conf = new Configuration();
// 宣告取得參數
String[] otherArgs = new GenericOptionsParser(conf, args)
.getRemainingArgs();
// 如果參數數量不為2 則印出提示訊息
if (otherArgs.length != 2) {
System.err
.println("Usage: hadoop jar HelloHadoopV3.jar <local_input> <local_output>");
System.exit(2);
}
Job job = new Job(conf, "Hadoop Hello World");
job.setJarByClass(HelloHadoopV3.class);
// set map and reduce class
job.setMapperClass(HelloMapperV2.class); // 輸入正確的mapper
job.setCombinerClass(HelloReducerV2.class); // 輸入正確的 class
job.setReducerClass(HelloReducerV2.class); // 輸入正確的 reducer
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);
// 用 checkAndDelete 函式防止overhead的錯誤
CheckAndDelete.checkAndDelete(hdfs_input, conf);
CheckAndDelete.checkAndDelete(hdfs_output, conf);
// 放檔案到hdfs
PutToHdfs.putToHdfs(args[0], hdfs_input, conf);
// 設定hdfs 的輸入輸出來源路定
FileInputFormat.addInputPath(job, new Path(hdfs_input));
FileOutputFormat.setOutputPath(job, new Path(hdfs_output));
long start = System.nanoTime();
job.waitForCompletion(true);
// 把hdfs的結果取下
GetFromHdfs.getFromHdfs(hdfs_output, args[1], conf);
boolean status = job.waitForCompletion(true);
// 計算時間
if (status) {
System.err.println("Integrate Alert Job Finished !");
long time = System.nanoTime() - start;
System.err.println(time * (1E-9) + " secs.");
} else {
System.err.println("Integrate Alert Job Failed !");
System.exit(1);
}
}
}