Mac版本的intellij14 开发hadoop程序环境搭建

1. 使用《Hadoop 权威指南》中的代码范例，三段代码如下：

package com.wozaizuo.count;

import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

public class MaxTemperatureMapper extends Mapper<LongWritable, Text, Text, IntWritable>
{
    private static final int MISSING = 9999;
    @Override
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException
    {
        String line = value.toString();
        String year = line.substring(15, 19);
        int airTemperature;
        if (line.charAt(87) == '+')
        {
            airTemperature = Integer.parseInt(line.substring(88, 92));
        }
        else
        {
            airTemperature = Integer.parseInt(line.substring(87, 92));
        }
        
        String quality = line.substring(92, 93);
        if (airTemperature != MISSING && quality.matches("[01459]"))
        {
            context.write(new Text(year), new IntWritable(airTemperature));
        }
    }
}

package com.wozaizuo.count;

import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

public class MaxTemperatureReducer extends Reducer<Text, IntWritable, Text, IntWritable> 
{
    @Override
    public void reduce(Text key, Iterable<IntWritable> values, Context context) throws Exception
    {
        int maxValue = Integer.MIN_VALUE;
        for (IntWritable value : values) 
        {
            maxValue = Math.max(maxValue, value.get());
        }
        context.write(key, new IntWritable(maxValue));
    }
}

package com.wozaizuo.count;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
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;

public class MaxTemperature
{
    public static void main(String[] args) throws Exception
    {
        if (args.length != 2) {
            System.err.println("Usage: MaxTemperature <input path> <output path>");
            System.exit(-1);
        }
        Job job = new Job();
        //job.setJarByClass(WordCount.class); 
        job.setJarByClass(MaxTemperature.class);
        job.setJobName("Max temperature");

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        job.setMapperClass(MaxTemperatureMapper.class);
        job.setReducerClass(MaxTemperatureReducer.class);

        job.setOutputKeyClass(Text.class);              //注1
        job.setOutputValueClass(IntWritable.class);

        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}