Question

我试图制作一个java程序，用一个线程中的阅读器和另一个线程中的编写器复制文件。该程序在不显示任何错误的情况下工作，但复制的文件与原始文件具有不同的校验和。我无法找到我在程序中犯的错误。该程序复制文本文件，他们似乎没有任何问题。当我尝试复制zip文件时，复制成功完成，但当我尝试提取复制的zip时，它显示zip文件已损坏。有人可以帮助我找到错误。

import java.io.*;
import java.util.concurrent.*;
import java.util.*;

class qu{
qu(byte[] b,int s){
    this.b=b;
    this.s=s;
} 
  byte[] b;
  int s;
 public String toString(){
     return s+"";
 }
}

class reader implements Runnable{
public byte[] b = new byte[1048576];
String inf;
int s;
long max;
private  BlockingQueue<qu> blockingQueue;
public reader(String inf,BlockingQueue<qu> blockingQueue,long max){
    this.inf=inf;
    this.max=max;
    this.blockingQueue=blockingQueue;
}

public void run(){
        RandomAccessFile in=null;
        try{
            in = new RandomAccessFile(inf,"rw");
            while((s=in.read(b))!=-1){
               blockingQueue.put(new qu(b,s));
            }

        }catch(Exception e){System.out.println(e);}
        finally{
            try{
                in.close();
            }catch(Exception e){System.out.println(e);}

        }


}
}

class writer implements Runnable{
public byte[] b = new byte[1048576];
String outf;
int s=0;
long max=0;
private  BlockingQueue<qu> blockingQueue;
public writer(String outf,BlockingQueue<qu> blockingQueue,long max){
    this.outf=outf;
    this.max=max;
    this.blockingQueue=blockingQueue;
}

public void run(){
        RandomAccessFile out;
        qu asd;
        System.out.println("Copying..");
        try{
            out = new RandomAccessFile(outf,"rw");
            while(out.getFilePointer()!=max){
                    asd=blockingQueue.take();
                    //System.out.println(new String(asd.b));
                    out.write(asd.b,0,asd.s);

            }
            out.close();
        }catch(Exception e){System.out.println(e);}

    }
}



class mul {

public static void main(String[] args) {
    String inf = args[0];
    String outf = args[1];
    File file =new File(inf);
    long max = file.length();
    BlockingQueue<qu> blockingQueue = new ArrayBlockingQueue<>(64);
    if(file.exists()){
        long start_time = System.nanoTime();
        Thread t1=new Thread(new reader(inf,blockingQueue,max));
        t1.start();
        Thread t2=new Thread(new writer(outf,blockingQueue,max));
        t2.start();
        try{
            t1.join();
            t2.join();
        }catch(Exception ex){System.out.println(ex);}
        long end_time = System.nanoTime();
        double difference = (end_time - start_time) / 1e6;
        System.out.println("Time taken: "+difference+"ms");
        System.out.println("Copy Completed..");

    }else{System.out.println("File not Found");}

}
}

Answer 1

您需要复制字节数组，例如

public class Qu {
    private final byte[] b;
    private final int s;

    public Qu(byte[] b,int s) {
        this.b = Arrays.copyOf(b, b.length);
        this.s = s;
    } 

    public String toString(){
        return s+"";
    }
}

具有不同线程中的读写器的Java复制文件（使用BlockingQueue）

1 个答案: