Commit cb4f46b3 authored by Meiqi Guo's avatar Meiqi Guo
Browse files

Add new file

parent 0e92823d
package ecp.BDPA.assignment1;
import java.io.BufferedReader;
import java.io.DataOutput;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.security.KeyStore.LoadStoreParameter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
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.input.FileSplit;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class InvertIndex extends Configured implements Tool {
private enum ONLY_WORD_COUNTER {
Single_Document;
}
public static void main(String[] args) throws Exception {
System.out.println(Arrays.toString(args));
Configuration conf = new Configuration();
conf.set("StopWordsFileName", args[2]);
// conf.set("mapreduce.map.output.compress", "true");
int res = ToolRunner.run(conf, new InvertIndex(), args);
System.exit(res);
}
@Override
public int run(String[] args) throws Exception {
System.out.println(Arrays.toString(args));
Job job = new Job(getConf(), "InvertIndex");
job.setJarByClass(InvertIndex.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
//job.setCombinerClass(Reduce.class);
job.setNumReduceTasks(10);
job.setInputFormatClass(TextInputFormat.class);
job.setOutputFormatClass(TextOutputFormat.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.waitForCompletion(true);
Integer i;
PrintWriter writer = new PrintWriter(args[3], "UTF-8");
i = (int) job.getCounters().findCounter(ONLY_WORD_COUNTER.Single_Document).getValue();
writer.println("Num Of Words Only In Single Document "+i.toString()+"\n");
writer.close();
return 0;
}
public static class Map extends Mapper<LongWritable, Text, Text, Text> {
private Text word = new Text();
private Text filename = new Text();
public List<Text> stopWords = new ArrayList<Text>();
public void loadStopWords(String filename) throws IOException{
Path pt=new Path(filename);//Location of file in HDFS
FileSystem fs = FileSystem.get(new Configuration());
BufferedReader br = new BufferedReader(new InputStreamReader(fs.open(pt)));
String sCurrentLine;
while ((sCurrentLine = br.readLine()) != null) {
String stopWord = sCurrentLine.replaceAll("[^A-Za-z]+", "");
Text t = new Text();
t.set(stopWord);
stopWords.add(t);
}
br.close();
return;
}
public void setup(Context context) throws IOException,InterruptedException {
super.setup(context);
String filename = context.getConfiguration().get("StopWordsFileName");
loadStopWords(filename);
}
@Override
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
FileSplit fileSplit = (FileSplit)context.getInputSplit();
String name = fileSplit.getPath().getName();
filename.set(name);
for (String token: value.toString().split("\\s+|-{2,}+")) {
word.set(token.replaceAll("[^A-Za-z]+", "").toLowerCase());
if (!stopWords.contains(word)){
context.write(word, filename);
}
}
}
}
public static class Reduce extends Reducer<Text, Text, Text, Text> {
@Override
public void reduce(Text key, Iterable<Text> values, Context context)
throws IOException, InterruptedException {
ArrayList<Text> list = new ArrayList<Text>();
for (Text value : values) {
list.add(new Text(value));
}
if (list.size()==1){
context.getCounter(ONLY_WORD_COUNTER.Single_Document).increment(1);
}
Set<Text> set = new HashSet<Text>(list);
String output = new String();
for (Text u : set){
output += u.toString();
//output += u.toString()+'#'+Collections.frequency(list, u);
output += ',';
}
output = output.substring(0, output.length()-1);
Text val = new Text();
val.set(output);
context.write(key, val);
}
}
}
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