七、统计网站中不同省份用户的访问数

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);
    }
    
}