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hdfs-site.xml
& lt; property>
,,,& lt; name> dfs.permissions
,,,& lt; value> false
& lt;/property>
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,,& lt; dependencies>
,,,& lt; dependency>
,,,,& lt; groupId> org.apache.hadoop
,,,,& lt; artifactId> hadoop-client
,,,,& lt; version> 2.7.3
& lt;/dependency>
,,,& lt; dependency>,,
,,,,,& lt; groupId> junit
,,,,,& lt; artifactId> junit
,,,,,& lt; version> 3.8.1
,,,,,& lt; scope> test
,,,& lt;/dependency>
& lt;才能/dependencies>
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import java.io.IOException;
import java.util.StringTokenizer;
,
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;
,
public class WordCount {
,
public 才能;static class TokenizerMapper
,,,,,,extends Mapper<对象,文本,文本,IntWritable> {
,,
,,,private final static IntWritable one =, new IntWritable (1);
,,,private Text word =, new 文本();
,,,,
,,,public void 地图(Object 关键,Text 价值,Context 上下文
,,,,,,,,,,,,,,,,,,,),throws IOException, InterruptedException {
,,,,,StringTokenizer itr =, new StringTokenizer (value.toString ());
,,,,,while (itr.hasMoreTokens ()), {
,,,,,,,word.set (itr.nextToken ());
,,,,,,,context.write (,,);
,,,,,}
,,,}
,,}
,
public 才能;static class IntSumReducer
,,,,,,extends Reducer<文本,IntWritable,文本,IntWritable>, {
,,,private IntWritable result =, new IntWritable ();
,
,,,public void 减少(Text 关键,Iterable,价值观,
,,,,,,,,,,,,,,,,,,,,,,Context 上下文
,,,,,,,,,,,,,,,,,,,,,,),throws IOException, InterruptedException {
,,,,,int sum =, 0;
,,,,,for (IntWritable val :值),{
,,,,,,,sum +=, val.get ();
,,,,,}
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