Changes between Initial Version and Version 1 of NCHCCloudCourse100928_4_EXM_sol

Timestamp:

Jul 21, 2011, 12:01:49 PM (13 years ago)

Author:

waue

Comment:

--

NCHCCloudCourse100928_4_EXM_sol

@@ +1 @@
+{{{
+#!java
+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.LongWritable;
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.mapreduce.Job;
+import org.apache.hadoop.mapreduce.Mapper;
+import org.apache.hadoop.mapreduce.Reducer;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+
+
+public class HelloHadoop {
+
+        static public class HelloMapper extends
+                        Mapper<LongWritable, Text, LongWritable, Text> {
+
+                public void map(LongWritable key, Text value, Context context)
+                                throws IOException, InterruptedException {
+                        // 將出入資料 原封不動的寫入 輸出
+                        context.write((LongWritable) key, (Text) value);
+                }
+
+        }
+
+        static public class HelloReducer extends
+                        Reducer<LongWritable, Text, LongWritable, Text> {
+                public void reduce(LongWritable key, Iterable<Text> values,
+                                Context context) throws IOException, InterruptedException {
+                        Text val = new Text();
+                        // 取回 val 的資料
+                        for (Text str : values) {
+                                val.set(str.toString());
+                        }
+                        // 將取回的資料引入輸出
+                        context.write(key, val);
+                }
+        }
+
+        public static void main(String[] args) throws IOException,
+                        InterruptedException, ClassNotFoundException {
+                // 引入 $HADOOP_HOME/conf 內控制檔內的資料
+                Configuration conf = new Configuration();
+                // 宣告job 取得conf 並設定名稱 Hadoop Hello World
+                Job job = new Job(conf, "Hadoop Hello World");
+                // 設定此運算的主程式
+                job.setJarByClass(HelloHadoop.class);
+                // 設定輸入路徑
+                FileInputFormat.setInputPaths(job, "/user/hadoop/input");
+                // 設定輸出路徑
+                FileOutputFormat.setOutputPath(job, new Path("/user/hadoop/output-hh1"));
+                // 指定定map class
+                job.setMapperClass(HelloMapper.class);
+                // 指定reduce class
+                job.setReducerClass(HelloReducer.class);
+                // 開使運算
+                job.waitForCompletion(true);
+
+        }
+}
+
+}}}