用Java简单实现文件分割与合并的事例

2007-12-19 10:35:08 来源:网页教学网

主要应用IO的RandomAccessFile(听说断点续传也是用它实现)

以下为引用的内容：

　import java.io.*;

class Fen{
String fileName;
int size;

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Fen(String fileName,String size){
this.fileName = fileName;
this.size = Integer.parseInt(size)*1024;
}

public void cut()throws Exception{
   int maxx = 0;
   File inFile = new File(fileName);

   int fileLength = (int)inFile.length(); //取得文件的大小
   int value;             //取得要分割的个数

   RandomAccessFile inn = new RandomAccessFile(inFile,"r");//打开要分割的文件


   value = fileLength/size;

   int i=0;
   int j=0;

   //根据要分割的数目输出文件
   for (;j    File outFile = new File(inFile.getName()+j+"zzii");
    RandomAccessFile outt= new RandomAccessFile(outFile,"rw");

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    maxx+=size;
    for (;i     outt.write(inn.read());
    }
    outt.close();
   }
   File outFile = new File(inFile.getName()+j+"zzii");
   RandomAccessFile outt= new RandomAccessFile(outFile,"rw");
   for(;i
    outt.write(inn.read());
   }
   outt.close();

   inn.close();
}
}

class He{
String fileName;
String filterName;

   He(String fileName,String filterName){
    this.fileName = fileName;
    this.filterName = filterName;
   }


   public void unite()throws Exception{
    String [] tt;
    File inFile = new File("."); //在当前目录下的文件
    File outFile = new File(fileName); //取得输出名
    RandomAccessFile outt= new RandomAccessFile(outFile,"rw");

    //取得符合条件的文件名
    tt = inFile.list(new FilenameFilter(){
     public boolean accept(File dir,String name){
      String rr = new File(name).toString();
      return rr.endsWith(filterName);

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     }
    });
    //打印出取得的文件名
    for (int i = 0;i     System.out.println(tt[i]);
    }

    //打开所有的文件再写入到一个文件里
    for(int i=0;i     inFile = new File(tt[i]);
     RandomAccessFile inn= new RandomAccessFile(inFile,"r");
     int c;
     while((c=inn.read())!=-1)
      outt.write(c);
    }

    outt.close();
   }
}

public class test{
public static void main(final String [] args)throws Exception{

if(args.length==0){
   print();
   return;
}
if(args[0].equals("-c")){
   Fen cutt = new Fen(args[1],args[2]);
   cutt.cut();
}
else if (args[0].equals("-r")){
   He hee = new He(args[1],args[2]);
   hee.unite();
}
else
   print();

}

public static void print(){
System.out.println("usage:\n分: java test -c file1 size(单位为K)\n合 java test -r file2 zzii(我设置的方便标识)");
}
}
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