如何对 Java 中的文本文件中的引用字符串进行排序

Question

I am trying to read list of quoted strings eg

"GJKFMN","OUYTV","VFRN","APLUI","DCFUYT","DXSER","JHGF","PIUYT","XSQ" 

from a text file and sort the words on alphabetical order. I also want to score each of these words in form of say A=1, B=2,... and sum the alphabets of each word.

I have tried this code below for the sorting but it's not sorting it for me:

public static void main(String[] args){
    String filePath = null;
    if (args[0] == null || args[0].isEmpty()) {
        System.out.println("Please Enter the Names File Path Enclosed in Double Quotes");
    }
    else {
        filePath = args[0];
    }
    List<String> bufferList = loadDataUsingBufferReader(filePath);
    List<String> listWithoutQuotes = removeQuotes(bufferList);
    listWithoutQuotes.parallelStream().map(String::toUpperCase).sorted().forEach(System.out::println);
}
public static List<String> removeQuotes(List<String> listWithQoutes) {
    listWithQoutes = listWithQoutes.stream().map(s -> s.replaceAll("\"", "")).collect(Collectors.toList());
    return listWithQoutes;
}
public static List<String> loadDataUsingBufferReader(String filePath) {
    final Charset ENCODING = StandardCharsets.UTF_8;
    List<String> lines = new LinkedList<>();
    try {
        final BufferedReader in = new BufferedReader(
                new InputStreamReader(new FileInputStream(filePath), ENCODING));
        String line;
        while ((line = in.readLine()) != null) {
            lines.add(line);
        }
        in.close();
    } catch (final IOException e) {
        e.printStackTrace();
    }
    return lines;
}

In the code I'm reading the file path from command line. When I hard code the input it sorts it but when I read from a file it doesn't. Performance is a key factor as the file could be as large as containing millions of words.

Thanks in advance for your help...

Answer 1

Using the following test data, which you just can copy-paste into a text file and use it as a sample file

"DSRD","KJHT","BFXXX","OUYTP"
"ABCD","XSHTKK","RTZI","HKLOPQ"
"BGTSZ","ASY","LOMCV","DESRAW"
"VMWEE","ERTZU","GSDFX","BHGFD"
"CD","FRTZU","JUHL","RETZ"

Something like below should work. I hope the method names are self explanatory and it is clear what happens in each step. I have included some println statements as a little debugging help. You should remove them if you are working with your original files which are possibly very large.

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Example {

    public static void main(String args[]) throws IOException {
        String filePath = null;
        if (args[0] == null || args[0].isEmpty()) {
            System.out.println("Please Enter the Names File Path Enclosed in Double Quotes");
        }
        else {
            filePath = args[0];
        }

        List<String> allLines = readAllLinesFromFile(filePath);
        allLines.forEach(System.out::println);
        System.out.println("**********************");

        List<String> listWithoutQuotes = removeQuotes(allLines);
        listWithoutQuotes.forEach(System.out::println);
        System.out.println("*****************");

        List<String> allWords = getAllWordsFromEachLineSorted(listWithoutQuotes);
        System.out.println(allWords);
        System.out.println("****************");

        List<Integer> scores = calculateStoreForAList(allWords);
        System.out.println(scores);
    }
    static List<String> readAllLinesFromFile(String fileName) throws IOException{
        return Files.readAllLines(Paths.get(fileName));
    }
    public static List<String> removeQuotes(List<String> listWithQoutes) {
        return listWithQoutes.stream()
                .map(s -> s.replaceAll("\"", ""))
                .collect(Collectors.toList());
    }
    public static List<String> getAllWordsFromEachLineSorted(List<String> lines) {
        return lines.stream()
                .map(s -> s.split("\\s*,\\s*"))
                .flatMap(Arrays::stream)
                .sorted()
                .collect(Collectors.toList());
    }

    static int calculateScore(String word){
        return word.chars()
                .map(i -> i-64)
                .sum();
    }
    static List<Integer> calculateStoreForAList(List<String> allWords){
        return allWords.stream()
                .map(str -> calculateScore(str))
                .collect(Collectors.toList());
    }
}

You should see something similar to

"DSRD","KJHT","BFXXX","OUYTP"
"ABCD","XSHTKK","RTZI","HKLOPQ"
"BGTSZ","ASY","LOMCV","DESRAW"
"VMWEE","ERTZU","GSDFX","BHGFD"
"CD","FRTZU","JUHL","RETZ"
**********************
DSRD,KJHT,BFXXX,OUYTP
ABCD,XSHTKK,RTZI,HKLOPQ
BGTSZ,ASY,LOMCV,DESRAW
VMWEE,ERTZU,GSDFX,BHGFD
CD,FRTZU,JUHL,RETZ
*****************
[ABCD, ASY, BFXXX, BGTSZ, BHGFD, CD, DESRAW, DSRD, ERTZU, FRTZU, GSDFX, HKLOPQ, JUHL, KJHT, LOMCV, OUYTP, RETZ, RTZI, VMWEE, XSHTKK]
****************
[10, 45, 80, 74, 27, 7, 70, 45, 90, 91, 60, 79, 51, 49, 65, 97, 69, 73, 68, 93]

Answer 2

After you removed double quotes from your text file, I would go with following steps;

Reading whole file as one string:

Path path = FileSystems.getDefault().getPath(directory, filename);
String fileContent = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);

Split the content into words since you have standard delimiter comma:

String[] words = fileContent.split(",");

Then sort it by using Arrays class built-in method:

Arrays.sort(words);

To calculate each word's score: capital "A" ascii decimal value is 65, so if you subtract 64 from each letters' ascii decimal value, you will find the score. For example:

String abc = "ABC";
int sum = 0;

for (int i = 0; i < abc.length(); ++i){
    sum += (int) abc.charAt(i) - 64;
} 

Here sum value is 6.