怎么用MapReduce列出工资比上司高的员工姓名及工资

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数据

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

      7369 SMITH      CLERK           7902 17-12月-80            800                    20      7499 ALLEN      SALESMAN        7698 20-2月 -81           1600        300         30      7521 WARD       SALESMAN        7698 22-2月 -81           1250        500         30      7566 JONES      MANAGER         7839 02-4月 -81           2975                    20      7654 MARTIN     SALESMAN        7698 28-9月 -81           1250       1400         30      7698 BLAKE      MANAGER         7839 01-5月 -81           2850                    30      7782 CLARK      MANAGER         7839 09-6月 -81           2450                    10      7839 KING       PRESIDENT            17-11月-81           5000                    10      7844 TURNER     SALESMAN        7698 08-9月 -81           1500          0         30      7900 JAMES      CLERK           7698 03-12月-81            950                    30      7902 FORD       ANALYST         7566 03-12月-81           3000                    20      7934 MILLER     CLERK           7782 23-1月 -82           1300                    10

代码

package cn.kissoft.hadoop.week07;import java.io.IOException;import java.text.DateFormat;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.List;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.conf.Configured;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.NullWritable;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;import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;import org.apache.hadoop.util.Tool;import org.apache.hadoop.util.ToolRunner;import cn.kissoft.hadoop.util.HdfsUtil;/** * Homework-05:列出工资比上司高的员工姓名及其工资 *  * @author wukong(jinsong.sun@139.com) */public class MorePayThanHigherups extends Configured implements Tool { public static class M extends Mapper {  @Override  public void map(LongWritable key, Text value, Context context)          throws IOException, InterruptedException {   String line = value.toString();   String id = line.substring(1, 11).trim();   String name = line.substring(11, 21).trim();   String sal = line.substring(57, 68).trim();   String pid = line.substring(32, 43).trim();   context.write(new Text(pid), new Text("EMP," + pid + "," + name           + "," + sal + "," + id));   context.write(new Text(id), new Text("BOSS," + id + "," + name           + "," + sal + "," + pid));  } } public static class R extends Reducer {  @Override  public void reduce(Text key, Iterable values, Context context)          throws IOException, InterruptedException {   String bossName = null;   int bossSal = 0;   List emps = new ArrayList();   for (Text value : values) {    System.out.println(value);    String[] ss = value.toString().split(",");    if (ss[0].equals("EMP")) {// 可能有多个     emps.add(new Emp(ss[2], Integer.parseInt(ss[3])));    } else if (ss[0].equals("BOSS")) {// 只有一个     bossName = ss[2];     bossSal = Integer.parseInt(ss[3]);    }   }   for (Emp e : emps) {    if (bossSal > 0 && e.getSal() > bossSal) {     context.write(null, new Text(e.getName() + "," + e.getSal()             + "," + bossName + "," + bossSal));    }   }  } } @Override public int run(String[] args) throws Exception {  Configuration conf = getConf();  Job job = new Job(conf, "Job-TotalSalaryByDeptMR");  job.setJarByClass(this.getClass());  job.setMapperClass(M.class);  job.setMapOutputKeyClass(Text.class);  job.setMapOutputValueClass(Text.class);  job.setReducerClass(R.class);  job.setOutputFormatClass(TextOutputFormat.class);  job.setOutputKeyClass(NullWritable.class); // 指定输出的KEY的格式  job.setOutputValueClass(Text.class); // 指定输出的VALUE的格式  FileInputFormat.addInputPath(job, new Path(args[0])); // 输入路径  FileOutputFormat.setOutputPath(job, new Path(args[1])); // 输出路径  return job.waitForCompletion(true) ? 0 : 1;  // job.waitForCompletion(true);  // return job.isSuccessful() ? 0 : 1; } /**  *   * @param args hdfs://bd11:9000/user/wukong/w07/emp.txt hdfs://bd11:9000/user/wukong/w07/out05/  * @throws Exception  */ public static void main(String[] args) throws Exception {  checkArgs(args);  HdfsUtil.rm(args[1], true);  Date start = new Date();  int res = ToolRunner.run(new Configuration(),          new MorePayThanHigherups(), args);  printExcuteTime(start, new Date());  System.exit(res); } /**  * 判断参数个数是否正确，如果无参数运行则显示以作程序说明。  *   * @param args  */ private static void checkArgs(String[] args) {  if (args.length != 2) {   System.err.println("");   System.err.println("Usage: Test_1 < input path > < output path > ");   System.err           .println("Example: hadoop jar ~/Test_1.jar hdfs://localhost:9000/home/james/Test_1 hdfs://localhost:9000/home/james/output");   System.err.println("Counter:");   System.err.println("\t" + "LINESKIP" + "\t"           + "Lines which are too short");   System.exit(-1);  } } /**  * 打印程序运行时间  *   * @param start  * @param end  */ private static void printExcuteTime(Date start, Date end) {  DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  float time = (float) ((end.getTime() - start.getTime()) / 60000.0);  System.out.println("任务开始：" + formatter.format(start));  System.out.println("任务结束：" + formatter.format(end));  System.out.println("任务耗时：" + String.valueOf(time) + " 分钟"); }}class Emp { private String name; private int sal; /**  * @param name  * @param sal  */ public Emp(String name, int sal) {  super();  this.name = name;  this.sal = sal; } public String getName() {  return name; } public int getSal() {  return sal; }}

运行结果

FORD,3000,JONES,2975

控制台

14/08/31 23:09:06 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable14/08/31 23:09:06 WARN mapred.JobClient: No job jar file set.  User classes may not be found. See JobConf(Class) or JobConf#setJar(String).14/08/31 23:09:07 INFO input.FileInputFormat: Total input paths to process : 114/08/31 23:09:07 WARN snappy.LoadSnappy: Snappy native library not loaded14/08/31 23:09:07 INFO mapred.JobClient: Running job: job_local1925230448_000114/08/31 23:09:07 INFO mapred.LocalJobRunner: Waiting for map tasks14/08/31 23:09:07 INFO mapred.LocalJobRunner: Starting task: attempt_local1925230448_0001_m_000000_014/08/31 23:09:07 INFO mapred.Task:  Using ResourceCalculatorPlugin : null14/08/31 23:09:07 INFO mapred.MapTask: Processing split: hdfs://bd11:9000/user/wukong/w07/emp.txt:0+111914/08/31 23:09:07 INFO mapred.MapTask: io.sort.mb = 10014/08/31 23:09:07 INFO mapred.MapTask: data buffer = 79691776/9961472014/08/31 23:09:07 INFO mapred.MapTask: record buffer = 262144/32768014/08/31 23:09:07 INFO mapred.MapTask: Starting flush of map output14/08/31 23:09:07 INFO mapred.MapTask: Finished spill 014/08/31 23:09:07 INFO mapred.Task: Task:attempt_local1925230448_0001_m_000000_0 is done. And is in the process of commiting14/08/31 23:09:07 INFO mapred.LocalJobRunner: 14/08/31 23:09:07 INFO mapred.Task: Task 'attempt_local1925230448_0001_m_000000_0' done.14/08/31 23:09:07 INFO mapred.LocalJobRunner: Finishing task: attempt_local1925230448_0001_m_000000_014/08/31 23:09:07 INFO mapred.LocalJobRunner: Map task executor complete.14/08/31 23:09:07 INFO mapred.Task:  Using ResourceCalculatorPlugin : null14/08/31 23:09:07 INFO mapred.LocalJobRunner: 14/08/31 23:09:07 INFO mapred.Merger: Merging 1 sorted segments14/08/31 23:09:07 INFO mapred.Merger: Down to the last merge-pass, with 1 segments left of total size: 766 bytes14/08/31 23:09:07 INFO mapred.LocalJobRunner: EMP,,KING,5000,7839BOSS,7369,SMITH,800,7902BOSS,7499,ALLEN,1600,7698BOSS,7521,WARD,1250,7698EMP,7566,FORD,3000,7902BOSS,7566,JONES,2975,7839BOSS,7654,MARTIN,1250,7698EMP,7698,WARD,1250,7521EMP,7698,JAMES,950,7900EMP,7698,MARTIN,1250,7654EMP,7698,ALLEN,1600,7499BOSS,7698,BLAKE,2850,7839EMP,7698,TURNER,1500,7844BOSS,7782,CLARK,2450,7839EMP,7782,MILLER,1300,7934BOSS,7839,KING,5000,EMP,7839,CLARK,2450,7782EMP,7839,BLAKE,2850,7698EMP,7839,JONES,2975,7566BOSS,7844,TURNER,1500,7698BOSS,7900,JAMES,950,7698EMP,7902,SMITH,800,7369BOSS,7902,FORD,3000,7566BOSS,7934,MILLER,1300,778214/08/31 23:09:07 INFO mapred.Task: Task:attempt_local1925230448_0001_r_000000_0 is done. And is in the process of commiting14/08/31 23:09:07 INFO mapred.LocalJobRunner: 14/08/31 23:09:07 INFO mapred.Task: Task attempt_local1925230448_0001_r_000000_0 is allowed to commit now14/08/31 23:09:07 INFO output.FileOutputCommitter: Saved output of task 'attempt_local1925230448_0001_r_000000_0' to hdfs://bd11:9000/user/wukong/w07/out0514/08/31 23:09:07 INFO mapred.LocalJobRunner: reduce > reduce14/08/31 23:09:07 INFO mapred.Task: Task 'attempt_local1925230448_0001_r_000000_0' done.14/08/31 23:09:08 INFO mapred.JobClient:  map 100% reduce 100/08/31 23:09:08 INFO mapred.JobClient: Job complete: job_local1925230448_000114/08/31 23:09:08 INFO mapred.JobClient: Counters: 1914/08/31 23:09:08 INFO mapred.JobClient:   File Output Format Counters 14/08/31 23:09:08 INFO mapred.JobClient:     Bytes Written=2114/08/31 23:09:08 INFO mapred.JobClient:   File Input Format Counters 14/08/31 23:09:08 INFO mapred.JobClient:     Bytes Read=111914/08/31 23:09:08 INFO mapred.JobClient:   FileSystemCounters14/08/31 23:09:08 INFO mapred.JobClient:     FILE_BYTES_READ=108214/08/31 23:09:08 INFO mapred.JobClient:     HDFS_BYTES_READ=223814/08/31 23:09:08 INFO mapred.JobClient:     FILE_BYTES_WRITTEN=13988214/08/31 23:09:08 INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=2114/08/31 23:09:08 INFO mapred.JobClient:   Map-Reduce Framework14/08/31 23:09:08 INFO mapred.JobClient:     Reduce input groups=1314/08/31 23:09:08 INFO mapred.JobClient:     Map output materialized bytes=77014/08/31 23:09:08 INFO mapred.JobClient:     Combine output records=014/08/31 23:09:08 INFO mapred.JobClient:     Map input records=1214/08/31 23:09:08 INFO mapred.JobClient:     Reduce shuffle bytes=014/08/31 23:09:08 INFO mapred.JobClient:     Reduce output records=114/08/31 23:09:08 INFO mapred.JobClient:     Spilled Records=4814/08/31 23:09:08 INFO mapred.JobClient:     Map output bytes=71614/08/31 23:09:08 INFO mapred.JobClient:     Total committed heap usage (bytes)=32610713614/08/31 23:09:08 INFO mapred.JobClient:     SPLIT_RAW_BYTES=10514/08/31 23:09:08 INFO mapred.JobClient:     Map output records=2414/08/31 23:09:08 INFO mapred.JobClient:     Combine input records=014/08/31 23:09:08 INFO mapred.JobClient:     Reduce input records=24任务开始：2014-08-31 23:09:06任务结束：2014-08-31 23:09:08任务耗时：0.023083333 分钟

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