沒有接觸的時候，以爲MapReduce只能通過遠程Hadoop虛擬機才能運行，學習了相關課程之後，發現這種計算也可以在本地運行，只是在部署的時候需要部署到遠程服務器上就行了
引入的pom.xml
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<hadoop.version>2.6.0-cdh5.15.1</hadoop.version>
</properties>
<repositories>
<repository>
<id>cloudera</id>
<url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</artifactId>
<version>${hadoop.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<scope>test</scope>
</dependency>
</dependencies>
WordCount詞頻統計案例
wordcount是最經典的案例，實現如下
Mapper
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
public class WordCountMapper extends Mapper<LongWritable, Text,Text, IntWritable>{
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
//super.map(key, value, context);
String[] words = value.toString().split("\t");
for (String word:words){
context.write(new Text(word),new IntWritable(1));
}
}
}
Reducer
public class WordCountReducer extends Reducer<Text, IntWritable,Text,IntWritable> {
@Override
protected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
//super.reduce(key, values, context);
int count=0;
Iterator<IntWritable> iterator = values.iterator();
while(iterator.hasNext()){
IntWritable value = iterator.next();
count+=value.get();
}
context.write(key,new IntWritable(count));
}
}
Driver
public static void main (String[] args) throws Exception {
Configuration configuration = new Configuration();
Job job = Job.getInstance(configuration);
job.setJarByClass(WordCountDriver.class);
job.setMapperClass(WordCountMapper.class);
job.setReducerClass(WordCountReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
FileInputFormat.setInputPaths(job,new Path("input"));
FileOutputFormat.setOutputPath(job,new Path("output"));
boolean result = job.waitForCompletion(true);
System.exit(result?0:1);
}
在項目目錄下創建input文件，並使用詞頻文件
hello world welcome
Hello Welcome
運行之後，可以得到結果
流量統計分析
自定義類
import org.apache.hadoop.io.Writable;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
public class Access implements Writable {
private String phone;
private long up;
private long down;
private long sum;
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public Access() {
}
public Access(String phone, long up, long down) {
this.phone = phone;
this.up = up;
this.down = down;
this.sum = up+down;
}
@Override
public void write(DataOutput dataOutput) throws IOException {
dataOutput.writeUTF(phone);
dataOutput.writeLong(up);
dataOutput.writeLong(down);
dataOutput.writeLong(sum);
}
@Override
public String toString() {
return phone +
"," + up +
"," + down +
"," + sum ;
}
@Override
public void readFields(DataInput in) throws IOException {
//注意與write方法的順序匹配
this.phone = in.readUTF();
this.up = in.readLong();
this.down = in.readLong();
this.sum = in.readLong();
}
public long getUp() {
return up;
}
public void setUp(long up) {
this.up = up;
}
public long getDown() {
return down;
}
public void setDown(long down) {
this.down = down;
}
public long getSum() {
return sum;
}
public void setSum(long sum) {
this.sum = sum;
}
}
Mapper
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
public class AccessMapper extends Mapper<LongWritable, Text,Text,Access> {
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String[] lines =value.toString().split("\t");
String phone = lines[1];
long up = Long.parseLong(lines[lines.length-3]);
long down =Long.parseLong(lines[lines.length-2]);
context.write(new Text(phone),new Access(phone,up,down));
}
}
Reducer
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import java.io.IOException;
public class AccessReducer extends Reducer<Text,Access,Text,Access> {
@Override
protected void reduce(Text key, Iterable<Access> values, Context context) throws IOException, InterruptedException {
long ups = 0;
long downs = 0;
for (Access access:values){
ups+= access.getUp();
downs+= access.getDown();
}
context.write(key,new Access(key.toString(),ups,downs));
}
}
Driver
public class AccessDriver {
public static void main(String[] args) throws Exception{
Configuration configuration = new Configuration();
Job job = Job.getInstance(configuration);
job.setJarByClass(AccessDriver.class);
job.setMapperClass(AccessMapper.class);
job.setReducerClass(AccessReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Access.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Access.class);
FileInputFormat.setInputPaths(job,new Path("access/input"));
FileOutputFormat.setOutputPath(job,new Path("access/output"));
boolean result = job.waitForCompletion(true);
System.exit(result?0:1);
}
}
輸入的文件內容
1363157985066 13726230503 00-FD-07-A4-72-B8:CMCC 120.196.100.82 i02.c.aliimg.com 24 27 2481 24681 200
1363157995052 13826544101 5C-0E-8B-C7-F1-E0:CMCC 120.197.40.4 4 0 264 0 200
1363157991076 13926435656 20-10-7A-28-CC-0A:CMCC 120.196.100.99 2 4 132 1512 200
1363154400022 13926251106 5C-0E-8B-8B-B1-50:CMCC 120.197.40.4 4 0 240 0 200
1363157993044 18211575961 94-71-AC-CD-E6-18:CMCC-EASY 120.196.100.99 iface.qiyi.com 視頻網站 15 12 1527 2106 200
1363157995074 84138413 5C-0E-8B-8C-E8-20:7DaysInn 120.197.40.4 122.72.52.12 20 16 4116 1432 200
1363157993055 13560439658 C4-17-FE-BA-DE-D9:CMCC 120.196.100.99 18 15 1116 954 200
1363157995033 15920133257 5C-0E-8B-C7-BA-20:CMCC 120.197.40.4 sug.so.360.cn 信息安全 20 20 3156 2936 200
1363157983019 13719199419 68-A1-B7-03-07-B1:CMCC-EASY 120.196.100.82 4 0 240 0 200
1363157984041 13660577991 5C-0E-8B-92-5C-20:CMCC-EASY 120.197.40.4 s19.cnzz.com 站點統計 24 9 6960 690 200
1363157973098 15013685858 5C-0E-8B-C7-F7-90:CMCC 120.197.40.4 rank.ie.sogou.com 搜索引擎 28 27 3659 3538 200
1363157986029 15989002119 E8-99-C4-4E-93-E0:CMCC-EASY 120.196.100.99 www.umeng.com 站點統計 3 3 1938 180 200
1363157992093 13560439658 C4-17-FE-BA-DE-D9:CMCC 120.196.100.99 15 9 918 4938 200
1363157986041 13480253104 5C-0E-8B-C7-FC-80:CMCC-EASY 120.197.40.4 3 3 180 180 200
1363157984040 13602846565 5C-0E-8B-8B-B6-00:CMCC 120.197.40.4 2052.flash2-http.qq.com 綜合門戶 15 12 1938 2910 200
1363157995093 13922314466 00-FD-07-A2-EC-BA:CMCC 120.196.100.82 img.qfc.cn 12 12 3008 3720 200
1363157982040 13502468823 5C-0A-5B-6A-0B-D4:CMCC-EASY 120.196.100.99 y0.ifengimg.com 綜合門戶 57 102 7335 110349 200
1363157986072 18320173382 84-25-DB-4F-10-1A:CMCC-EASY 120.196.100.99 input.shouji.sogou.com 搜索引擎 21 18 9531 2412 200
1363157990043 13925057413 00-1F-64-E1-E6-9A:CMCC 120.196.100.55 t3.baidu.com 搜索引擎 69 63 11058 48243 200
1363157988072 13760778710 00-FD-07-A4-7B-08:CMCC 120.196.100.82 2 2 120 120 200
1363157985066 13726238888 00-FD-07-A4-72-B8:CMCC 120.196.100.82 i02.c.aliimg.com 24 27 2481 24681 200
1363157993055 13560436666 C4-17-FE-BA-DE-D9:CMCC 120.196.100.99 18 15 1116 954 200
1363157985066 13726238888 00-FD-07-A4-72-B8:CMCC 120.196.100.82 i02.c.aliimg.com 24 27 10000 20000 200
輸出內容
