豆
package com.zhengkw.rawcomparabletest;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.file.tfile.RawComparable;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
/**
* @ClassName:FlowBean
* @author: zhengkw
* @description:
* @date: 20/03/02下午 8:09
* @version:1.0
* @since: jdk 1.8
*/
public class FlowBean implements Writable {
//上行数据
private Long upFlow;
//下行数据
private Long downFlow;
//总量
private Long totalFlow;
public FlowBean() {
}
public void setUpFlow(Long upFlow) {
this.upFlow = upFlow;
}
public void setDownFlow(Long downFlow) {
this.downFlow = downFlow;
}
public void setTotalFlow(Long totalFlow) {
this.totalFlow = totalFlow;
}
public Long getUpFlow() {
return upFlow;
}
public Long getDownFlow() {
return downFlow;
}
public Long getTotalFlow() {
return totalFlow;
}
public void set(Long upFlow, Long downFlow) {
this.upFlow = upFlow;
this.downFlow = downFlow;
this.totalFlow = upFlow + downFlow;
}
@Override
public void write(DataOutput out) throws IOException {
out.writeLong(upFlow);
out.writeLong(downFlow);
out.writeLong(totalFlow);
}
@Override
public void readFields(DataInput in) throws IOException {
this.upFlow = in.readLong();
this.downFlow = in.readLong();
this.totalFlow = in.readLong();
}
@Override
public String toString() {
return upFlow +
"\t" + downFlow +
"\t" + totalFlow;
}
}
RawComparator実装クラス
package com.zhengkw.rawcomparabletest;
import org.apache.hadoop.io.DataInputBuffer;
import org.apache.hadoop.io.RawComparator;
import java.io.IOException;
/**
* @ClassName:RawComparatorTest
* @author: zhengkw
* @description:
* @date: 20/03/02下午 8:17
* @version:1.0
* @since: jdk 1.8
*/
public class RawComparatorTest implements RawComparator<FlowBean> {
FlowBean flowBean1 = new FlowBean();
FlowBean flowBean2 = new FlowBean();
DataInputBuffer inputBuffer = new DataInputBuffer();
@Override
public int compare(FlowBean o1, FlowBean o2) {
/*
if (o1.getTotalFlow() > o2.getTotalFlow()) {
return -1;
} else if (o1.getTotalFlow() == o2.getTotalFlow()) {
return 0;
} else return 1;
*/
//简化
return - o1.getTotalFlow().compareTo(o2.getTotalFlow());
}
/**
* Compare two objects in binary.
* b1[s1:l1] is the first object, and b2[s2:l2] is the second object.
*
* @param b1 The first byte array.
* @param s1 The position index in b1. The object under comparison's starting index.
* @param l1 The length of the object in b1.
* @param b2 The second byte array.
* @param s2 The position index in b2. The object under comparison's starting index.
* @param l2 The length of the object under comparison in b2.
* @return An integer result of the comparison.
*/
@Override
public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
try {
inputBuffer.reset(b1, s1, l1);
flowBean1.readFields(inputBuffer);
inputBuffer.reset(b2, s2, l2);
flowBean2.readFields(inputBuffer);
} catch (IOException e) {
e.printStackTrace();
}
return compare(flowBean1, flowBean2);
}
}
マッパー
package com.zhengkw.rawcomparabletest;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
/**
* @ClassName:FlowMapper
* @author: zhengkw
* @description:
* @date: 20/03/02下午 8:08
* @version:1.0
* @since: jdk 1.8
*/
public class FlowMapper extends Mapper<LongWritable, Text, FlowBean, NullWritable> {
FlowBean k = new FlowBean();
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String line = value.toString();
String[] info = line.split("\t");
Long upFlow = Long.parseLong(info[info.length - 3]);
Long downFlow = Long.parseLong(info[info.length - 2]);
k.set(upFlow, downFlow);
context.write(k, NullWritable.get());
}
}
レデューサー
package com.zhengkw.rawcomparabletest;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
/**
* @ClassName:FlowReducer
* @author: zhengkw
* @description:
* @date: 20/03/02下午 8:09
* @version:1.0
* @since: jdk 1.8
*/
public class FlowReducer extends Reducer<FlowBean, NullWritable, FlowBean, NullWritable> {
@Override
protected void reduce(FlowBean key, Iterable<NullWritable> values, Context context) throws IOException, InterruptedException {
context.write(key, NullWritable.get());
}
}
運転者
package com.zhengkw.rawcomparabletest;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;
/**
* @ClassName:FlowDriver
* @author: zhengkw
* @description:
* @date: 20/03/02下午 8:09
* @version:1.0
* @since: jdk 1.8
*/
public class FlowDriver {
public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
Path input = new Path("F:\\mrinput\\sort");
Path output = new Path("F:/output5");
Configuration conf = new Configuration();
//conf.set(KeyValueLineRecordReader.KEY_VALUE_SEPERATOR,"\t");
FileSystem fs = FileSystem.get(conf);
if (fs.exists(output)) {
fs.delete(output, true);
}
//反射创建对象
Job job = Job.getInstance(conf);
//给job指定RawComparator比较器
job.setSortComparatorClass(RawComparatorTest.class);
//job.setNumReduceTasks(1);
//设置3个类
job.setJarByClass(FlowDriver.class);
job.setMapperClass(FlowMapper.class);
job.setReducerClass(FlowReducer.class);
//设置2个输入输出
// job.setMapOutputKeyClass(N.class);
// job.setMapOutputValueClass(FlowBean.class);
// 指定最终输出的数据的kv类型
job.setOutputKeyClass(FlowBean.class);
job.setOutputValueClass(NullWritable.class);
// job.setInputFormatClass(KeyValueTextInputFormat.class);
//指定输入输出路径
FileInputFormat.setInputPaths(job, input);
FileOutputFormat.setOutputPath(job, output);
//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);
}
}
テストデータ
13470253144 180 180 360
13509468723 7335 110349 117684
13560439638 918 4938 5856
13568436656 3597 25635 29232
13590439668 1116 954 2070
13630577991 6960 690 7650
13682846555 1938 2910 4848
13729199489 240 0 240
13736230513 2481 24681 27162
13768778790 120 120 240
13846544121 264 0 264
13956435636 132 1512 1644
13966251146 240 0 240
13975057813 11058 48243 59301
13992314666 3008 3720 6728
15043685818 3659 3538 7197
15910133277 3156 2936 6092
15959002129 1938 180 2118
18271575951 1527 2106 3633
18390173782 9531 2412 11943
84188413 4116 1432 5548
結果
7335 110349 117684
11058 48243 59301
3597 25635 29232
2481 24681 27162
9531 2412 11943
6960 690 7650
3659 3538 7197
3008 3720 6728
3156 2936 6092
918 4938 5856
4116 1432 5548
1938 2910 4848
1527 2106 3633
1938 180 2118
1116 954 2070
132 1512 1644
180 180 360
264 0 264
240 0 240
120 120 240
240 0 240
問題が発生しました
通常、以下の結果出力の数の後に第1条
コードのバグ
@Override
public int compare(FlowBean o1, FlowBean o2) {
return o1.getTotalFlow() > o2.getTotalFlow()?-1:0;
}
補正後
@Override
public int compare(FlowBean o1, FlowBean o2) {
if (o1.getTotalFlow() > o2.getTotalFlow()) {
return -1;
} else if (o1.getTotalFlow() == o2.getTotalFlow()) {
return 0;
} else return 1;
}
compato比較条件が洗練されていません。
2.EOFException
理由:
中のDataInputStreamのreadFullyメソッド数<0 、次の図につながります。
カウント(すなわち、空白行)を読み取るためのデータがない場合入力ストリームメソッドを取得するために、リード(3つのパラメータ)と呼ばれ、図-1
解決策:
データ・ソースを洗浄、空行を削除することができます!
注意事項
設定されていないsortComparatorクラスは、ドライバのエラーで表示されます
ソースソース
、それはwritableComparable実装クラスである場合、例外が発生します。これはデフォルトですので、あなたはsortComparatorを指定する必要があるため
//给job指定RawComparator比较器
job.setSortComparatorClass(RawComparatorTest.class);