一、需求

针对log日志中给定的信息，统计网站中不同省份用户的访问数

二、编程代码

package org.apache.hadoop.studyhdfs.mapreduce; import java.io.IOException; import org.apache.commons.lang.StringUtils; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; 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.Mapper.Context; 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.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.jboss.netty.util.internal.StringUtil; public class ProvinceCountMapReduce extends Configured implements Tool { //1.map /* * <KEYIN,VALUEIN,KEYOUT,VALUEOUT> */ public static class WordCountMapper extends Mapper<LongWritable,Text,IntWritable,IntWritable>{ private IntWritable mapOutputKey =new IntWritable(); private IntWritable mapOutputValue =new IntWritable(1); @Override public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { //get lineValue String lineValue =value.toString(); //split String[] strs =lineValue.split("t"); //line blank String url=strs[1]; String provinceIdValue =strs[23]; //guolv if(strs.length < 30 || StringUtils.isBlank(provinceIdValue) || StringUtils.isBlank(url)){ return; } int provinceId =Integer.MAX_VALUE; try { provinceId=Integer.valueOf(provinceIdValue); } catch (Exception e) { return; } if(provinceId == Integer.MAX_VALUE){ return; } mapOutputKey.set(provinceId); context.write(mapOutputKey, mapOutputValue); } } //2.reduce public static class WordCountReduce extends Reducer<IntWritable,IntWritable,IntWritable,IntWritable>{ private IntWritable outputValue =new IntWritable(); @Override public void reduce(IntWritable key, Iterable<IntWritable> values,Context context) throws IOException, InterruptedException { //to do int sum = 0; for(IntWritable value:values){ sum +=value.get(); } outputValue.set(sum); context.write(key, outputValue); } } public int run(String[] args) throws Exception{ //1.get Configuration Configuration conf =super.getConf(); //2.create job Job job =Job.getInstance(conf, this.getClass().getSimpleName()); job.setJarByClass(ProvinceCountMapReduce.class); //3.set job //3.1 set input Path inputPath =new Path(args[0]); FileInputFormat.addInputPath(job, inputPath); //3.2 set mapper job.setMapperClass(WordCountMapper.class); job.setMapOutputKeyClass(IntWritable.class); job.setMapOutputValueClass(IntWritable.class); //3.3 set reduce job.setReducerClass(WordCountReduce.class); job.setOutputKeyClass(IntWritable.class); job.setOutputValueClass(IntWritable.class); //3.4 set input Path outputPath =new Path(args[1]); FileOutputFormat.setOutputPath(job, outputPath); //4.submmit boolean isSuccess =job.waitForCompletion(true); return isSuccess?0:1; } public static void main(String[] args) throws Exception { args =new String[]{ "hdfs://Hadoop-senior02.beifeng.com:8020/input/2015082818", "hdfs://Hadoop-senior02.beifeng.com:8020/output15/" }; Configuration conf =new Configuration(); conf.set("mapreduce.map.output.compress", "true"); int status=ToolRunner.run(conf, new ProvinceCountMapReduce() , args); System.exit(status); } }

3、运行结果

1）运行代码：bin/hdfs dfs -text /output15/par*

2）运行结果：

1 3527

2 1672

3 511

4 325

5 776

6 661

7 95

8 80

9 183

10 93

11 135

12 289

13 264

14 374

15 163

16 419

17 306

18 272

19 226

20 2861

21 124

22 38

23 96

24 100

25 20

26 157

27 49

28 21

29 85

30 42

32 173

以上所述是小编给大家介绍的Java代码统计网站中不同省份用户的访问数的相关介绍，希望对大家有所帮助，在此小编也非常感谢大家对查字典教程网的支持！