Question

Hiho伙计们，我正在编写一个简单的应用程序，它应该打开两个.txt文件，获取第一个文件的第一行，然后遍历第二个文件的每一行。如果它在第二个文件中找到相同的String，那么它应该使用nextline将此字符串写入outputfile.txt。在完成第二个文件的循环之后，它应该从第一行获取第二行并搜索相同的String，如果找到则用nextline写入它。我自己尝试了但它什么也没做，我的意思是它没有把任何文本放到outputfile.txt中，即使我确定有相同的单词。

package com.company;

import java.io.*;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Scanner;

public class Main {

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

    String sourceFileName = "C:\\Users\\Maciej\\IdeaProjects\\spring5webapp\\FileTextChecker\\src\\com\\company\\BootfileRO.txt";
    String comparingFileName = "C:\\Users\\Maciej\\IdeaProjects\\spring5webapp\\FileTextChecker\\src\\com\\company\\BootfileSK.txt";
    String outputFileName = "C:\\Users\\Maciej\\IdeaProjects\\spring5webapp\\FileTextChecker\\src\\com\\company\\output.txt";

    System.out.println("Starting ...  ");



    File file1 = new File(sourceFileName);
    File file2 = new File(comparingFileName);
    PrintWriter file3 = new PrintWriter(outputFileName);

    String line1 = "";
    String line2 = "";

    Scanner scan1 = new Scanner(file1);
    Scanner scan2 = new Scanner(file2);
    while(scan1.hasNextLine()){
        line1 = scan1.nextLine();
        while(scan2.hasNextLine()){
            line2 = scan2.nextLine();
            if(line1.equals(line2)){
                file3.println(line1);
            }
            else{
                continue;
            }
        }


    }
    file3.close();





   // Comparer comparer = new Comparer(sourceFileName, comparingFileName, oFN);
   // comparer.compare();


   // CompareByScanner compareBYScanner = new CompareByScanner(sourceFileName, comparingFileName, outputFileName);
   // compareBYScanner.compare();


    }


}

老实说，看起来“equals”函数找不到相同的字符串，但我确信它们存在。

Answer 1

这里的问题是scan2永远不会重置，因此在比较file1的第一行之后，scan2.hasNextLine（）将返回false，因此不会比较任何其他行。相反，在scan1循环的每次迭代中将scan2设置为等于新的Scanner。这会将其设置为文件的开头。然后，扫描文件后，关闭扫描仪。新代码：

package test;

import java.io.*;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Scanner;

public class TestMain {

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

String sourceFileName = "src/output/compare1.txt";
String comparingFileName = "src/output/compare2.txt";
String outputFileName = "src/output/output.txt";

System.out.println("Starting ...  ");



File file1 = new File(sourceFileName);
File file2 = new File(comparingFileName);
PrintWriter file3 = new PrintWriter(outputFileName);

String line1 = "";
String line2 = "";

Scanner scan1 = new Scanner(file1);
Scanner scan2;
while(scan1.hasNextLine()){
    line1 = scan1.nextLine();
    scan2 = new Scanner(file2);
    while(scan2.hasNextLine()){
        line2 = scan2.nextLine();
        System.out.println("Line 1: " + line1 + "\n" + "Line 2: " + line2);
        if(line1.equals(line2)){
            file3.println(line1);
        }
    }
    scan2.close();
}
file3.close();





// Comparer comparer = new Comparer(sourceFileName, comparingFileName, oFN);
// comparer.compare();


// CompareByScanner compareBYScanner = new CompareByScanner(sourceFileName, 
comparingFileName, outputFileName);
// compareBYScanner.compare();


}


}

File Comparer不会将结果写入文件

1 个答案: