tencent cloud

[root@172 ~]# su hadoop
[hadoop@172 root]$ cd /usr/local/service/hadoop
[hadoop@172 hadoop]$

Hello World.
this is a message.
this is another message.
Hello world, how are you?

scp $localfile root@public IP address:$remotefolder

[hadoop@172 hadoop]$ ls –l

[hadoop@172 hadoop]$ hadoop fs -put /usr/local/service/hadoop/test.txt /user/hadoop/

[hadoop@172 hadoop]$ hadoop fs -ls /user/hadoop
Output:
-rw-r--r-- 3 hadoop supergroup 85 2018-07-06 11:18 /user/hadoop/test.txt

[hadoop@172 hadoop]$ hadoop fs –mkdir /user/hadoop

mvn     archetype:generate     -DgroupId=$yourgroupID     -DartifactId=$yourartifactID 
-DarchetypeArtifactId=maven-archetype-quickstart

simple
　　　---pom.xml　　　　Core configuration, under the project root directory
　　　---src
　　　　　---main　　　　　　
　　　　　　　---java　　　　  Java source code directory
　　      　---resources　  Java configuration file directory
　　　　---test
　　　　　　---java　　　　  Test source code directory
　　　　　　---resources　  Test configuration directory

<dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>2.7.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-mapreduce-client-core</artifactId>
            <version>2.7.3</version>
        </dependency>
</dependencies>

<build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>utf-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
</build>

import org.apache.hadoop.conf.Configuration;
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.Mapper;
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.GenericOptionsParser;

import java.io.IOException;
import java.util.StringTokenizer;

/**
 * Created by tencent on 2018/7/6.
 */
public class WordCount {
    public static class TokenizerMapper
            extends Mapper<Object, Text, Text, IntWritable>
    {
        private static final IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(Object key, Text value, Mapper<Object, Text, Text, IntWritable>.Context context)
                throws IOException, InterruptedException
        {
            StringTokenizer itr = new StringTokenizer(value.toString());
            while (itr.hasMoreTokens())
            {
                this.word.set(itr.nextToken());
                context.write(this.word, one);
            }
        }
    }

    public static class IntSumReducer
            extends Reducer<Text, IntWritable, Text, IntWritable>
    {
        private IntWritable result = new IntWritable();

        public void reduce(Text key, Iterable<IntWritable> values, Reducer<Text, IntWritable, Text, IntWritable>.Context context)
                throws IOException, InterruptedException
        {
            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            this.result.set(sum);
            context.write(key, this.result);
        }
    }

    public static void main(String[] args)
            throws Exception
    {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length < 2)
        {
            System.err.println("Usage: wordcount <in> [<in>...] <out>");
            System.exit(2);
        }
        Job job = Job.getInstance(conf, "word count");
        job.setJarByClass(WordCount.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setCombinerClass(IntSumReducer.class);
        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        for (int i = 0; i < otherArgs.length - 1; i++) {
            FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
        }
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[(otherArgs.length - 1)]));

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

mvn package

scp $jarpackage root@public IP address: /usr/local/service/hadoop

[hadoop@10 hadoop]$ bin/hadoop jar 
/usr/local/service/hadoop/WordCount-1.0-SNAPSHOT-jar-with-dependencies.jar
WordCount /user/hadoop/test.txt /user/hadoop/WordCount_output

[hadoop@172 hadoop]$ hadoop fs -ls /user/hadoop/WordCount_output
Found 2 items
-rw-r--r-- 3 hadoop supergroup 0 2018-07-06 11:35 /user/hadoop/MEWordCount_output/_SUCCESS
-rw-r--r-- 3 hadoop supergroup 82 2018-07-06 11:35 /user/hadoop/MEWordCount_output/part-r-00000

[hadoop@172 hadoop]$ hadoop fs -cat /user/hadoop/MEWordCount_output/part-r-00000
Hello	2
World.	1
a	1
another	1
are	1
how	1
is	2
message.	2
this	2
world,	1
you?	1……

[hadoop@10 hadoop]$ hadoop jar
/usr/local/service/hadoop/WordCount-1.0-SNAPSHOT-jar-with-dependencies.jar
WordCount cosn://$bucketname/test.txt cosn://$bucketname /WordCount_output

[hadoop@10 hadoop]$ hadoop fs -ls cosn:// $bucketname /WordCount_output
Found 2 items
-rw-rw-rw- 1 hadoop Hadoop 0 2018-07-06 10:34 cosn://$bucketname /WordCount_output/_SUCCESS
-rw-rw-rw- 1 hadoop Hadoop 1306 2018-07-06 10:34 cosn://$bucketname /WordCount_output/part-r-00000

[hadoop@10 hadoop]$ hadoop fs -cat cosn:// $bucketname /WordCount_output1/part-r-00000
Hello	2
World.	1
a	1
another	1
are	1
how	1
is	2
message.	2
this	2
world,	1
you?	1