通过字节数组问题进行文件比较

Question

我正在编写一个类,通过比较每个文件的字节数组来比较两个目录的文件.然而,我没有得到预期的结果; 相同的文件未被解析为相同的文件.

第一个问题:

匹配文件Byte [] with equals()使用匹配文件解析为false(仅检查一个文件以避免可能的索引错位问题;检查仍然解析为false.).

第二个问题:

当使用Vector的containsAll()来检查Byte []的两个Vector是否匹配时(每个目录有一个Vector,每个文件有一个Byte []),即使是相同的目录,这个检查结果为false(此检查已从下面的代码中删除.) .那么我对齐两个向量的方式有问题吗？(我已经使用两个目录检查了这一点,其中匹配的文件以相同的顺序加载到匹配的indeces中;这仍然导致Vector不匹配).

第三个问题:

当检查目录中存在子目录时,将抛出未找到文件的异常,表明访问被拒绝.为什么会这样？我怎么能绕过这个呢？我不想检查子目录中包含的文件,但我正在设计代码,以便最终用户不必担心被比较目录的子目录.这只有在存在子目录时才会发生,当被检查的目录中没有子目录时,它可以正常工作.

示例异常:

Byte reading error!
Byte reading error!
java.io.FileNotFoundException: C:\Dir1\Dir2\Dir3\Dir4\SubDir (Access is denied)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(Unknown Source)
    at tools.filesystem.filecomparison.FileComparator.getBytes(FileComparator.java:166)
    at tools.filesystem.filecomparison.FileComparator.main(FileComparator.java:102)
java.io.FileNotFoundException: C:\Dir1\Dir2\Dir3\Dir4\SubDir Files (Access is denied)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(Unknown Source)
    at tools.filesystem.filecomparison.FileComparator.getBytes(FileComparator.java:166)
    at tools.filesystem.filecomparison.FileComparator.main(FileComparator.java:111)

这是代码:

package tools.filesystem.filecomparison;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;
import java.util.Vector;

public class FileComparator
{
    public static void main(String[] args)
    {
        String workingDir1 = "";
        String workingDir2 = "";

        File[] fileArr1 = null;
        File[] fileArr2 = null;

        Vector<File> fileVec1 = new Vector<File>();
        Vector<File> fileVec2 = new Vector<File>();

        Scanner console = new Scanner(System.in);
        while (true)
        {
            System.out.println("Enter working directory one . . . .");
            workingDir1 = console.nextLine();
            workingDir1.replace("\\", "\\\\");

            System.out.println("Enter working directory two . . . .");
            workingDir2 = console.nextLine();
            workingDir2.replace("\\", "\\\\");

            File folder1 = new File(workingDir1);
            File[] listOfFiles1 = folder1.listFiles();

            File folder2 = new File(workingDir1);
            File[] listOfFiles2 = folder2.listFiles();

            fileArr1 = listOfFiles1;
            fileArr2 = listOfFiles2;

            System.out.println("\nWorking Directory 1 Files\n");
            for (int i = 0; i < listOfFiles1.length; i++)
            {
                if (listOfFiles1[i].isFile())
                {
                    System.out.println("    " + listOfFiles1[i].getName());
                } 
/*              else if (listOfFiles1[i].isDirectory())
                {
                    System.out.println("Directory " + listOfFiles1[i].getName());
                }*/
            }

            System.out.println("\nWorking Directory 2 Files\n");
            for (int i = 0; i < listOfFiles2.length; i++)
            {
                if (listOfFiles2[i].isFile())
                {
                    System.out.println("    " + listOfFiles2[i].getName());
                } 
/*              else if (listOfFiles2[i].isDirectory())
                {
                    System.out.println("Directory " + listOfFiles2[i].getName());
                }*/
            }

            for (File fle : fileArr1)
            {
                fileVec1.add(fle);
            }

            for (File fle : fileArr2)
            {
                fileVec2.add(fle);
            }

            if (fileVec1.containsAll(fileVec2))
                break;
            else
            {
                System.out.println("Directories do not contain the same files!\nContinue anyways? y/n?");
                if (console.nextLine().equalsIgnoreCase("y"))
                    break;
                else if (console.nextLine().equalsIgnoreCase("n"))
                    continue;   
            }
        }

        Vector<Vector<File>> alignedVectors = align(fileVec1, fileVec2);

        fileVec1 = alignedVectors.elementAt(0);
        fileVec2 = alignedVectors.elementAt(1);

        Vector<byte[]> fileByteVect1 =  new Vector<byte[]>();
        Vector<byte[]> fileByteVect2 =  new Vector<byte[]>();
        try
        {
            fileByteVect1 = getBytes(fileVec1);
        } 
        catch (IOException e)
        {
            System.out.println("Byte reading error!");
            e.printStackTrace();
        }
        try
        {
            fileByteVect2 = getBytes(fileVec2);
        } 
        catch (IOException e)
        {
            System.out.println("Byte reading error!");
            e.printStackTrace();
        }

        boolean[] check = new boolean[fileByteVect1.capacity()];

        int i1 = 0;
        //debug
        for (byte[] e : fileByteVect1)
        {
            System.out.println("Vector 1 count " + i1);
            System.out.println(e.toString());
            for (byte b : e)
            {
                System.out.print(b + " ");
            }
            i1++;
        }

        int i2 = 0;
        //debug
        for (byte[] e : fileByteVect2)
        {
            System.out.println("Vector 2 count " + i2);
            System.out.println(e.toString());
            for (byte b : e)
            {
                System.out.print(b + " ");
            }
            i2++;
        }

        if (fileByteVect1.size() == fileByteVect2.size())
        {
            System.out.println(fileByteVect1.size());
            for (int i = 0; i < fileByteVect1.size(); i++ )
            {
                if (fileByteVect1.elementAt(i).equals(fileByteVect2.elementAt(i)))
                {
                    check[i] = true;
                    System.out.println("File at index " + i + " are identical");
                }
                else
                {
                    check[i] = false;
                    System.out.println("File at index " + i + " are not identical");
                }
            }
        }
        else
            System.out.println("Files do not match!");
    }

    public static Vector<Vector<File>> align(Vector<File> fileVect1, Vector<File> fileVect2)
    {
        Vector<Vector<File>> mainBuffer = new Vector<Vector<File>>();
        Vector<File> bufferFileVect = new Vector<File>();
        for (File fle1 : fileVect1)
        {
            for (File fle2 : fileVect2)
            {
                if (fle1.getName().equals(fle2.getName()))
                    bufferFileVect.add(fle2);
            }
        }

        mainBuffer.add(fileVect1);
        mainBuffer.add(bufferFileVect);

        return mainBuffer;
    }

    public static Vector<byte[]> getBytes(Vector<File> fileVector) throws IOException
    {
        Vector<byte[]> outVector = new Vector<byte[]>();

        for (File file : fileVector)
        {
            InputStream is = new FileInputStream(file);

            // Get the size of the file
            long length = file.length();

            if (length > Integer.MAX_VALUE)
            {
                System.out.println("File is too large!");
            }

            // Create the byte array to hold the data
            byte[] bytes = new byte[(int) length];

            // Read in the bytes
            int offset = 0;
            int numRead = 0;
            while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0)
            {
                offset += numRead;
            }

            // Ensure all the bytes have been read in
            if (offset < bytes.length)
            {
                throw new IOException("Could not completely read file " + file.getName());
            }

            // Close the input stream and return bytes
            outVector.add(bytes);
            is.close();
        }
        return outVector;
    }
}

Answer 1

该equals函数没有进行深入的比较,而是为了byte[]比较地址.相反,你应该使用

Arrays.equals(fileByteVect1.elementAt(i), fileByteVect2.elementAt(i))

执行字节数组的深度比较.

关于Arrays.equals的更多细节.

至于你的第三个问题,你实际上并不只是过滤文件.当您遍历打印出文件名时,您应该构建存储文件的Vector:

for (File fle : fileArr1) {
    if (fle.isFile()) {
        fileVec1.add(fle);
        System.out.println("    " + fle.getName());
    }
}

你会的,当然,要为做到这一点fileArr2,并fileVec2为好.