hadoop 全面解读自定义分区

1863157985066 120.196.100.82 2481 24681 200
1363157995033 120.197.40.4 264 0 200
1373157993055 120.196.100.99 132 1512 200
1393154400022 120.197.40.4 240 0 200
1363157993044 120.196.100.99 1527 2106 200
1397157993055 120.197.40.4 4116 1432 200
1463157993055 120.196.100.99 1116 954 200
1383157995033 120.197.40.4 3156 2936 200
1363157983019 120.196.100.82 240 0 200
1383154400022 120.197.40.4 6960 690 200
1363157973098 120.197.40.4 3659 3538 200
1373157993055 120.196.100.99 1938 180 200
1363154400022 120.196.100.99 918 4938 200
1393157993055 120.197.40.4 180 180 200
1363157984040 120.197.40.4 1938 2910 200

public class PhoneMapper extends Mapper {
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String line = value.toString(); //拿到一行数据
String[] fields = line.split(“\s+”); //切分成各个字段
String phoneNumber = fields[0]; //拿到手机号的字段
//封装数据为key-value进行输出
context.write(new Text(phoneNumber), value);
}
}

public class PhonePartitioner extends Partitioner {
@Override
public int getPartition(Text key, Text value, int numPartitions) {
String preNum = key.toString().substring(0, 3); // 1 获取电话号码的前三位
int partition = 4;
switch (preNum) {
case “136”:
partition = 0;
break;
case “137”:
partition = 1;
break;
case “138”:
partition = 2;
break;
case “139”:
partition = 3;
break;
default:
break;
}
return partition;
}
}

public class PhoneReducer extends Reducer {
int index = 0;
@Override
protected void reduce(Text key, Iterable values, Context context) throws IOException, InterruptedException {
index++;
context.write(new LongWritable(index), values.iterator().next());
}
}

public class PhoneDriver {
public static void main(String[] args) throws Exception {
args = new String[2];
args[0] = “src/main/resources/phonei”;
args[1] = “src/main/resources/phoneo”;

    // 1 获取配置信息，或者job对象实例
    Configuration cfg = new Configuration();
    //设置本地模式运行（即使项目类路径下core-site.xml文件，依然采用本地模式）
    cfg.set("mapreduce.framework.name", "local");
    cfg.set("fs.defaultFS", "file:///");
    Job job = Job.getInstance(cfg);
    // 2 指定本程序的jar包所在的本地路径
    job.setJarByClass(PhoneDriver.class);
    // 3 指定本业务job要使用的mapper/Reducer业务类
    job.setMapperClass(PhoneMapper.class);
    job.setReducerClass(PhoneReducer.class);
    // 4 指定mapper输出数据的kv类型
    job.setMapOutputKeyClass(Text.class);
    job.setMapOutputValueClass(Text.class);
    // 5 指定最终输出的数据的kv类型
    job.setOutputKeyClass(LongWritable.class);
    job.setOutputValueClass(Text.class);
    // 8 指定自定义数据分区
    job.setPartitionerClass(PhonePartitioner.class);
    // 9 同时指定相应数量的reduce task(必须指定)
    job.setNumReduceTasks(5);  //----①
    // 6 指定job的输入原始文件所在目录
    FileInputFormat.setInputPaths(job, new Path(args[0]));
    FileOutputFormat.setOutputPath(job, new Path(args[1]));
    // 7 将job中配置的相关参数，以及job所用的java类所在的jar包， 提交给yarn去运行
    boolean result = job.waitForCompletion(true);
    System.exit(result ? 0 : 1);
}
}