java.io.filenotfoundexception下载zip并提取它 [英] java.io.filenotfoundexception downloading zip and extracting it

问题描述

我制作了一个小程序，从直接链接下载zip文件，然后将其中的所有内容提取到同一目录中。
它不下载任何东西，也没有提取。
这是我迄今为止所做的：

  package main; 
 
 import java.io.BufferedOutputStream; 
 import java.io.File; 
 import java.io.FileInputStream; 
 import java.io.FileOutputStream; 
 import java.io.IOException; 
 import java.net.URL; 
 import java.nio.channels.Channels; 
 import java.nio.channels.ReadableByteChannel; 
 import java.util.zip.ZipEntry; 
 import java.util.zip.ZipInputStream; 
 
 public class Main {
 
 static String url =https://www.dropbox.com/s/uml938guklfvo7r/Tekst.zip?dl=1; 
 static int lastSlashIndex = url.lastIndexOf（'/'）; 
 static String filename = url.substring（lastSlashIndex + 1，url.length（） -  5）; 
 static String filepath =C：; 
 private static final int BUFFER = 4096; 
 
 public static void main（String [] args）{
 
 try {
 URL website = new URL（url）; 
 ReadableByteChannel rbc; 
 rbc = Channels.newChannel（website.openStream（））; 
 new File（filepath + filename）.createNewFile（）; 
 FileOutputStream fos = new FileOutputStream（filepath + filename）; 
 fos.getChannel（）。transferFrom（rbc，0，Long.MAX_VALUE）; 
 fos.close（）; 
} catch（Exception e）{e.printStackTrace（）; } 
 
 try {
 unzip（filepath + filename，filepath）; 
} catch（IOException e）{
 e.printStackTrace（）; 
} 
 
 
 
 
 public static void unzip（String zipFilePath，String destDirectory）throws IOException {
 File destDir = new File（ destDirectory）; 
 if（！destDir.exists（））{
 destDir.mkdir（）; 
} 
 ZipInputStream zipIn = new ZipInputStream（new FileInputStream（zipFilePath））; 
 ZipEntry entry = zipIn.getNextEntry（）; 
 //遍历zip文件
中的条目（entry！= null）{
 String filePath = destDirectory + File.separator + entry.getName（）; 
 if（！entry.isDirectory（））{
 //如果条目是一个文件，提取它
 extractFile（zipIn，filePath）; 
} else {
 //如果条目是一个目录，使目录
 File dir = new File（filePath）; 
 dir.mkdir（）; 
} 
 zipIn.closeEntry（）; 
 entry = zipIn.getNextEntry（）; 
} 
 zipIn.close（）; 
} 
 
 private static void extractFile（ZipInputStream zipIn，String filePath）throws IOException {
 Line 68>> BufferedOutputStream bos = new BufferedOutputStream（new FileOutputStream（filePath））; 
 byte [] bytesIn = new byte [BUFFER]; 
 int read = 0; 
 while（（read = zipIn.read（bytesIn））！= -1）{
 bos.write（bytesIn，0，read）; 
} 
 bos.close（）; 
} 
} 
  

这是错误：

  java.io.FileNotFoundException：C：\Tekst.txt（访问被拒绝）
在java.io.FileOutputStream.open（Native方法）
在java.io.FileOutputStream。< init>（未知源）
在java.io.FileOutputStream。< init>（未知源）
在main.Main.extractFile （Main.java:68）
在main.Main.unzip（Main.java:55）
在main.Main.main（Main.java:35）
  

解决方案

显然这个文件根本没有创建。您可以使用

 创建新文件（yourFilepath）.createNewFile（）
  / pre> 
 
 
，您需要在之前 
  FileOutputStream fos = new FileOutputStream（filepath + filename）; 
  
其中引发异常。然后它工作得很好。
 
I made a small program to download a zip file from a direct link and after that extract all contents of it in the same directory.
It doesn't download anything and it also doesn't extract.
This is what I have so far:
package main;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class Main {

    static String url = "https://www.dropbox.com/s/uml938guklfvo7r/Tekst.zip?dl=1";
    static int lastSlashIndex = url.lastIndexOf('/');
    static String filename= url.substring(lastSlashIndex + 1, url.length() - 5);
    static String filepath = "C:";
    private static final int BUFFER = 4096;

    public static void main(String[] args) {

        try{
            URL website = new URL(url);
            ReadableByteChannel rbc;
            rbc = Channels.newChannel(website.openStream());
            new File(filepath + filename).createNewFile();
            FileOutputStream fos = new FileOutputStream(filepath + filename);
            fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
            fos.close();
        }catch(Exception e){ e.printStackTrace(); }

        try {
            unzip(filepath + filename, filepath);
        } catch (IOException e) {
            e.printStackTrace();
        }


    }

    public static void unzip(String zipFilePath, String destDirectory) throws IOException {
        File destDir = new File(destDirectory);
        if (!destDir.exists()) {
            destDir.mkdir();
        }
        ZipInputStream zipIn = new ZipInputStream(new FileInputStream(zipFilePath));
        ZipEntry entry = zipIn.getNextEntry();
        // iterates over entries in the zip file
        while (entry != null) {
            String filePath = destDirectory + File.separator + entry.getName();
            if (!entry.isDirectory()) {
                // if the entry is a file, extracts it
                extractFile(zipIn, filePath);
            } else {
                // if the entry is a directory, make the directory
                File dir = new File(filePath);
                dir.mkdir();
            }
            zipIn.closeEntry();
            entry = zipIn.getNextEntry();
        }
        zipIn.close();
    }

    private static void extractFile(ZipInputStream zipIn, String filePath) throws IOException {
        Line 68>> BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
        byte[] bytesIn = new byte[BUFFER];
        int read = 0;
        while ((read = zipIn.read(bytesIn)) != -1) {
            bos.write(bytesIn, 0, read);
        }
        bos.close();
    }  
}
Here is the error:
java.io.FileNotFoundException: C:\Tekst.txt (Access is denied)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at java.io.FileOutputStream.<init>(Unknown Source)
    at main.Main.extractFile(Main.java:68)
    at main.Main.unzip(Main.java:55)
    at main.Main.main(Main.java:35)

解决方案
Apparently this file is simply not created yet. You can create it with
new File(yourFilepath).createNewFile()
and you need to do it before you invoke
FileOutputStream fos = new FileOutputStream(filepath + filename);
which throws the exception. Then it works perfectly fine.

                        
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