java - 如何从目录或文件夹中读取重复字数

Question

我从编码站点获得了以下程序。

以下代码读取文本文件并查找重复的单词。

读取每个文本文件并逐行显示重复字数。以及如果文件未存储为字符串，如何调用该文件，我使用了缓冲读取器，但没有得到输出。

我的问题:

1. 如何让程序从给定的文件夹中读取多个文件？

2. 如何将结果保存为Excel文件格式？

欢迎提出任何建议。

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Map.Entry;


public class MaxDuplicateWordCount {

    public Map<String, Integer> getWordCount(String fileName){

        FileInputStream fis = null;
        DataInputStream dis = null;
        BufferedReader br = null;
        Map<String, Integer> wordMap = new HashMap<String, Integer>();

        try {
            fis = new FileInputStream(fileName);
            dis = new DataInputStream(fis);
            br = new BufferedReader(new InputStreamReader(dis));
            String line = null; 
            while((line = br.readLine()) != null){
                StringTokenizer st = new StringTokenizer(line, " ");
                while(st.hasMoreTokens()){
                    String tmp = st.nextToken().toLowerCase();
                    if(wordMap.containsKey(tmp)){
                        wordMap.put(tmp, wordMap.get(tmp)+1);
                    } else {
                        wordMap.put(tmp, 1);
                    }
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try{if(br != null) br.close();}catch(Exception ex){}
        }
        return wordMap;
    }

    public List<Entry<String, Integer>> sortByValue(Map<String, Integer> wordMap){

        Set<Entry<String, Integer>> set = wordMap.entrySet();
        List<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(set);
        Collections.sort( list, new Comparator<Map.Entry<String, Integer>>()
        {
            public int compare( Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2 )
            {
                return (o2.getValue()).compareTo( o1.getValue() );
            }
        } );
        return list;
    }

    public static void main(String a[]){



        MaxDuplicateWordCount mdc = new MaxDuplicateWordCount();
        Map<String, Integer> wordMap = mdc.getWordCount("E:\\Blog 39.txt");

        List<Entry<String, Integer>> list = mdc.sortByValue(wordMap);
        for(Map.Entry<String, Integer> entry:list){
            System.out.println(entry.getKey()+" ="+entry.getValue());
        }
    }
}

Answer 1

介绍

在与 OP 交谈后，以下是 OP 的简要要求:

1- 从特定文件夹读取文件，文件通常是 Unicode 文本文件。
2- 文件将在问题中的 OP 算法中处理，算法的结果应再次保存在 Unicode 文件中(后来 OP 要求保存为 Excel 文件(.XLS)，因为 Unicode 与 Excel 兼容)

解决方案

这可以通过以下步骤解决:

第 1 步我们定义(声明)我们的工作空间
第 2 步 如果不存在，我们在工作空间中创建输出文件夹
第 3 步 我们读取工作空间文件夹中的所有现有文件并在算法中处理它们。
第 4 步每个文件的结果将在输出文件夹中保存为 Excel 文件。

代码

首先您需要导入 POI 包，这将允许您创建 XLS 表。我已经下载了这个poi/poi-3.5-FINAL.jar.zip( 1,372 k)并且应将以下导入添加到您的代码中。

import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFRow;

接下来您将以下代码添加到您的代码中，它是 self 解释的代码:

final static String WORKSPACE = "C:/testfolder/";

private static void createOutputFolder(String outputFolderName) {
    File outputDirectory = new File(WORKSPACE + outputFolderName);

    if (!outputDirectory.exists()) {
        try {
            outputDirectory.mkdir();
        } catch (Exception e) {
        }
    }
}

private static void exlCreator() {

    String outputFolder = "output/";
    String fileName, fileNameWPathInput;
    int serialNumber = 1;
    createOutputFolder(outputFolder);

    MaxDuplicateWordCount mdc = new MaxDuplicateWordCount();
    File folder = new File(WORKSPACE);
    File[] listOfFiles = folder.listFiles();

    for (int i = 0; i < listOfFiles.length; i++) {
        if (listOfFiles[i].isFile()) {
            fileName = listOfFiles[i].getName();
            fileNameWPathInput = WORKSPACE + fileName;
            Map<String, Integer> wordMap = mdc.getWordCount(fileNameWPathInput);
            List<Entry<String, Integer>> list = mdc.sortByValue(wordMap);
            String fileNameWPathOutput = WORKSPACE + outputFolder +
                    fileName.substring(0, fileName.length() - 4)
                    + "output.xls";
            try {
                HSSFWorkbook workbook = new HSSFWorkbook();
                HSSFSheet sheet = workbook.createSheet("ResultSheet");

                HSSFRow rowhead = sheet.createRow((short) 0);
                rowhead.createCell(0).setCellValue("Serial No.");
                rowhead.createCell(1).setCellValue("Word");
                rowhead.createCell(2).setCellValue("Count");

                for (Map.Entry<String, Integer> entry : list) {
                    HSSFRow row = sheet.createRow((short) serialNumber);
                    row.createCell(0).setCellValue(serialNumber);
                    row.createCell(1).setCellValue(entry.getKey());
                    row.createCell(2).setCellValue(entry.getValue());
                    serialNumber++;
                }
                FileOutputStream fileOut = new FileOutputStream(fileNameWPathOutput);
                workbook.write(fileOut);
                fileOut.close();
                serialNumber = 1;
                System.out.println(fileNameWPathOutput + " is created");

            } catch (Exception ex) {
                System.out.println(ex);
            }
        }
    }


}

public static void main(String [] args) throws IOException {
    exlCreator();
}

最后

通过操作代码，可以创建一个输出文件，但在工作表中创建每个输出结果。如下图所示，输出文件在 Excel 中打开，显示 Unicode 文本没有问题，因为这是我第一个解决方案中的问题:

链接

Download POI
POI documentation
Unicode problem in CSV
More about CSV

完整代码，从 OP 请求

import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Map.Entry;
//for Excel ark
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFRow;

public class MaxDuplicateWordCount {

    public Map<String, Integer> getWordCount(String fileName) {

        FileInputStream fis = null;
        DataInputStream dis = null;
        BufferedReader br = null;
        Map<String, Integer> wordMap = new HashMap<String, Integer>();

        try {
            fis = new FileInputStream(fileName);
            dis = new DataInputStream(fis);
            br = new BufferedReader(new InputStreamReader(dis));
            String line = null;
            while ((line = br.readLine()) != null) {
                StringTokenizer st = new StringTokenizer(line, " ");
                while (st.hasMoreTokens()) {
                    String tmp = st.nextToken().toLowerCase();
                    if (wordMap.containsKey(tmp)) {
                        wordMap.put(tmp, wordMap.get(tmp) + 1);
                    } else {
                        wordMap.put(tmp, 1);
                    }
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null) br.close();
            } catch (Exception ex) {
            }
        }
        return wordMap;
    }

    public List<Entry<String, Integer>> sortByValue(Map<String, Integer> wordMap) {

        Set<Entry<String, Integer>> set = wordMap.entrySet();
        List<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(set);
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {

            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {

                return (o2.getValue()).compareTo(o1.getValue());
            }


        });
        return list;
    }

    final static String WORKSPACE = "C:/testfolder/";

    private static void createOutputFolder(String outputFolderName) {
        File outputDirectory = new File(WORKSPACE + outputFolderName);

        if (!outputDirectory.exists()) {
            try {
                outputDirectory.mkdir();
            } catch (Exception e) {
            }
        }
    }

    private static void exlCreator() {

        String outputFolder = "output/";
        String fileName, fileNameWPathInput;
        int serialNumber = 1;
        createOutputFolder(outputFolder);

        MaxDuplicateWordCount mdc = new MaxDuplicateWordCount();
        File folder = new File(WORKSPACE);
        File[] listOfFiles = folder.listFiles();

        for (int i = 0; i < listOfFiles.length; i++) {
            if (listOfFiles[i].isFile()) {
                fileName = listOfFiles[i].getName();
                fileNameWPathInput = WORKSPACE + fileName;
                Map<String, Integer> wordMap = mdc.getWordCount(fileNameWPathInput);
                List<Entry<String, Integer>> list = mdc.sortByValue(wordMap);
                String fileNameWPathOutput = WORKSPACE + outputFolder +
                        fileName.substring(0, fileName.length() - 4)
                        + "output.xls";
                try {
                    HSSFWorkbook workbook = new HSSFWorkbook();
                    HSSFSheet sheet = workbook.createSheet("ResultSheet");

                    HSSFRow rowhead = sheet.createRow((short) 0);
                    rowhead.createCell(0).setCellValue("Serial No.");
                    rowhead.createCell(1).setCellValue("Word");
                    rowhead.createCell(2).setCellValue("Count");

                    for (Map.Entry<String, Integer> entry : list) {
                        HSSFRow row = sheet.createRow((short) serialNumber);
                        row.createCell(0).setCellValue(serialNumber);
                        row.createCell(1).setCellValue(entry.getKey());
                        row.createCell(2).setCellValue(entry.getValue());
                        serialNumber++;
                    }
                    FileOutputStream fileOut = new FileOutputStream(fileNameWPathOutput);
                    workbook.write(fileOut);
                    fileOut.close();
                    serialNumber = 1;
                    System.out.println(fileNameWPathOutput + " is created");

                } catch (Exception ex) {
                    System.out.println(ex);
                }
            }
        }


    }

    public static void main(String[] args) throws IOException {
        exlCreator();
    }
}