用Java簡單實現(xiàn)文件分割與合并

codeman 2006-09-11

展開全文

主要應用IO的RandomAccessFile(聽說斷點續(xù)傳也是用它實現(xiàn))
　import java.io.*;

class Fen{
String fileName;
int size;

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;             //取得要分割的個數(shù)

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


   value = fileLength/size;

   int i=0;
   int j=0;

   //根據要分割的數(shù)目輸出文件
   for (;j<value;j++){
    File outFile = new File(inFile.getName()+j+"zzii");
    RandomAccessFile outt= new RandomAccessFile(outFile,"rw");
    maxx+=size;
    for (;i<maxx;i++){
     outt.write(inn.read());
    }
    outt.close();
   }
   File outFile = new File(inFile.getName()+j+"zzii");
   RandomAccessFile outt= new RandomAccessFile(outFile,"rw");
   for(;i<fileLength;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("."); //在當前目錄下的文件
    File outFile = new File(fileName);  //取得輸出名
    RandomAccessFile outt= new RandomAccessFile(outFile,"rw");

    //取得符合條件的文件名
    tt = inFile.list(new FilenameFilter(){
     public boolean accept(File dir,String name){
      String rr = new File(name).toString();
      return rr.endsWith(filterName);
     }
    });
    //打印出取得的文件名
    for (int i = 0;i<tt.length;i++){
     System.out.println(tt[i]);
    }

    //打開所有的文件再寫入到一個文件里
    for(int i=0;i<tt.length;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(單位為K)\n合 java test -r file2 zzii(我設置的方便標識)");
}
}