java - 错误，我无法删除临时文件或将其替换为原始文件java

Question

我试图删除临时文件或将临时文件替换为原始文件。但是我不知道该怎么做。谁能帮助我或者指出我该更改哪一部分？

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

        final File inputFile = new File("myFile.txt");
        final File tempFile = new File("myTempFile.txt");
        tempFile.delete();
        BufferedReader reader = null;
        BufferedWriter writer = null;
        try {
            reader = new BufferedReader(new FileReader(inputFile));
            writer = new BufferedWriter(new FileWriter(tempFile));
    
            final String lineToRemove1 = "Apple";
            final String lineToRemove2 = "Orange";
            String currentLine;
            while((currentLine = reader.readLine()) != null) {
                // trim newline when comparing with lineToRemove
                final String trimmedLine = currentLine.trim();
                if (!currentLine.contains(lineToRemove1) 
                        && !currentLine.contains(lineToRemove2)) {
                    writer.write(currentLine);
                    writer.newLine();
                }
            }
        }
        
        finally {
            if (reader != null) { 
                reader.close();
            }
            if (writer != null) {
                writer.close();
            } 
        }  
        FileChannel src = new FileInputStream(tempFile).getChannel();
        FileChannel dest = new FileOutputStream(inputFile).getChannel();
        dest.transferFrom(src, 0, src.size());
        tempFile.delete();
    }
}

Answer 1

package com.example.servingwebcontent;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.channels.FileChannel;

public class Deletion {
    public static void main(String[] args) throws IOException, URISyntaxException {
        System.out.println(System.getProperty("user.dir"));

        FileReader reader = new FileReader("myFile.txt");
        BufferedReader bufferedReader = new BufferedReader(reader);

        FileWriter writer = new FileWriter("myTempFile.txt", false);

        try {

            final String lineToRemove1 = "Apple";
            final String lineToRemove2 = "Orange";
            String currentLine = bufferedReader.readLine();
            while (currentLine != null) {
                // trim newline when comparing with lineToRemove
                final String trimmedLine = currentLine.trim();
                if (!(currentLine.contains(lineToRemove1) || currentLine.contains(lineToRemove2))) {
                    writer.write(currentLine);
                    // new line
                    writer.write("\r\n");
                }
                currentLine = bufferedReader.readLine();
            }
        }

        finally {

            if (reader != null) {
                reader.close();
                reader = null;
                bufferedReader = null;
            }
            if (writer != null) {
                writer.close();
                writer = null;

            }
        }

        FileChannel sourceChannel = null;
        FileChannel destChannel = null;
        File src = new File("myTempFile.txt");
        File dest = new File("myFile.txt");
        try {

            sourceChannel = new FileInputStream(src).getChannel();
            destChannel = new FileOutputStream(dest).getChannel();
            destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());

        } finally {
            sourceChannel.close();
            destChannel.close();
            src.delete();
        }

    }
}

试试这个代码。这里的问题是必须关闭资源(src.delete()；必须在sourceChannel.close()和destChannel.close();之后)，否则您将无法删除文件。
引用: Java 'file.delete()' Is not Deleting Specified File
67
该问题也可能是由于您忘记关闭任何输出流而导致的。就我而言，在删除文件之前，我正在使用该文件。但是，在文件操作中的某个地方，我忘记了关闭用于写入后来试图删除的文件的输出流。