[英]How to count words in a text file, java 8-style
I'm trying to perform an assignment that first counts the number of files in a directory and then give a word count within each file.我正在尝试执行一个分配,首先计算目录中的文件数,然后给出每个文件中的字数。 I got the file count alright, but I'm having a hard time converting some code my instructor gave me from a class that does a frequency count to the simpler word count.
我的文件计数没问题,但是我很难将老师给我的一些代码从进行频率计数的课程转换为更简单的字数计数。 Moreover, I can't seem to find the proper code to look at each file to count the words (I'm trying to find something "generic" rather than a specific, but I trying to test the program using a specific text file).
此外,我似乎无法找到正确的代码来查看每个文件以计算单词(我试图找到“通用”而不是特定的东西,但我尝试使用特定的文本文件测试程序) . This is the intended output:
这是预期的输出:
Count 11 files:
word length: 1 ==> 80
word length: 2 ==> 321
word length: 3 ==> 643
However, this is what's being outputted instead:但是,这是输出的内容:
primes.txt
but
are
sometimes
sense
refrigerator
make
haiku
dont
they
funny
word length: 1 ==> {but=1, are=1, sometimes=1, sense=1, refrigerator=1, make=1, haiku=1, dont=1, they=1, funny=1}
.....
Count 11 files:
I'm using two classes: WordCount and FileCatch8我正在使用两个类:WordCount 和 FileCatch8
WordCount:字数:
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.AbstractMap.SimpleEntry;
import java.util.Arrays;
import java.util.Map;
import static java.util.stream.Collectors.counting;
import static java.util.stream.Collectors.groupingBy;
/**
*
* @author
*/
public class WordCount {
/**
*
* @param filename
* @return
* @throws java.io.IOException
*/
public Map<String, Long> count(String filename) throws IOException {
//Stream<String> lines = Files.lines(Paths.get(filename));
Path path = Paths.get("haiku.txt");
Map<String, Long> wordMap = Files.lines(path)
.parallel()
.flatMap(line -> Arrays.stream(line.trim().split(" ")))
.map(word -> word.replaceAll("[^a-zA-Z]", "").toLowerCase().trim())
.filter(word -> word.length() > 0)
.map(word -> new SimpleEntry<>(word, 1))
//.collect(Collectors.toMap(s -> s, s -> 1, Integer::sum));
.collect(groupingBy(SimpleEntry::getKey, counting()));
wordMap.forEach((k, v) -> System.out.println(String.format(k,v)));
return wordMap;
}
}
And FileCatch:和 FileCatch:
import java.io.IOException;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author
*/
public class FileCatch8 {
public static void main(String args[]) {
List<String> fileNames = new ArrayList<>();
try {
DirectoryStream<Path> directoryStream = Files.newDirectoryStream
(Paths.get("files"));
int fileCounter = 0;
WordCount wordCnt = new WordCount();
for (Path path : directoryStream) {
System.out.println(path.getFileName());
fileCounter++;
fileNames.add(path.getFileName().toString());
System.out.println("word length: " + fileCounter + " ==> " +
wordCnt.count(path.getFileName().toString()));
}
} catch(IOException ex){
}
System.out.println("Count: "+fileNames.size()+ " files");
}
}
The program uses Java 8 streams with lambda syntax该程序使用带有 lambda 语法的 Java 8 流
Word count example:字数示例:
Files.lines(Paths.get(file))
.flatMap(line -> Arrays.stream(line.trim().split(" ")))
.map(word -> word.replaceAll("[^a-zA-Z]", "").toLowerCase().trim())
.filter(word -> !word.isEmpty())
.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
Files count:文件数:
Files.walk(Paths.get(file), Integer.MAX_VALUE).count();
Files.walk(Paths.get(file)).count();
In my opinion, the simplest way to count the words in a file using Java 8 is this:在我看来,使用 Java 8 计算文件中单词的最简单方法是:
Long wordsCount = Files.lines(Paths.get(file))
.flatMap(str->Stream.of(str.split("[ ,.!?\r\n]")))
.filter(s->s.length()>0).count();
System.out.println(wordsCount);
And to count all the files:并计算所有文件:
Long filesCount = Files.walk(Paths.get(file)).count();
System.out.println(filesCount);
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