java文件流操作相关

1.通过文件字节流复制文件

    public class HelloWorld {

	/**
	 * @param args
	 */
	
	public static void main(String[] args)
	{ 
	 int b=0;
	 FileReader in=null;
	 FileWriter out=null;
	 try
	 {
		 in=new FileReader("H:/hellworld.txt");
		 out=new FileWriter("h:/hw.txt");		 
                   while((b=in.read())!=-1)
		 {
			 out.write(b);
		 }
		 out.close();
		 in.close();
	 }
	 catch(FileNotFoundException e)
	 {
		 System.out.println("找不到指定文件"); System.exit(-1);

	 }
	 catch(IOException e)
	 {
		 System.out.println("文件复制错误"); System.exit(-1);

	 }
	 System.out.println("successed!");
	}

	
}

2.通过文件字符流复制文件

public class HelloWorld {

	/**
	 * @param args
	 */
	
	public static void main(String[] args)
	{ 
	 int b=0;
	 FileInputStream in=null;
	 FileOutputStream out=null;
	 try
	 {
		 in=new FileInputStream("H:/hellworld.txt");
		 out=new FileOutputStream("h:/hw.txt");
		 while((b=in.read())!=-1)
		 {
			 out.write(b);
		 }
		 out.close();
		 in.close();
	 }
	 catch(FileNotFoundException e)
	 {
		 System.out.println("找不到指定文件"); System.exit(-1);

	 }
	 catch(IOException e)
	 {
		 System.out.println("文件复制错误"); System.exit(-1);

	 }
	 System.out.println("successed!");
	}

	
}

3.用 InputStream & DataInputStream 这两个基类来进行读操作

try
{
  FileInputStream fstream=new FileInputStream(filepath);
  DataInputStream in=new DataInputStream(fstream);
  while(in.avaliable()!=0)
  {
    System.out.println(in.readLine());
  }
  in.close();
 }
 catch (Exception e) 
 { 
   System.err.println("File input error");        
 }   

4.用 OutputStream & PrintStream这两个基类来进行写操作

FileOutputStream out;
 PrintStream p;
try
{
 out = new FileOutputStream("myfile.txt");   
  p = new PrintStream( out );   
  p.println ("This is written to a file");        
  p.close();   
}
catch(Exception e)
{
 System.err.println ("Error writing to file");   
}

5.通过FileReader来进行读操作

 try {    
     FileReader fr = new FileReade("mydata.txt");
     BufferedReader br = new BufferedReader(fr);
     record = new String();        
     while ((record = br.readLine()) != null) 
     {           
        recCount++;           
        System.out.println(recCount + ": " + record);   
     }  
     br.close();  
     fr.close();        
     }
      catch (IOException e) 
     {             
       System.out.printl("Uoh,gotIOExceptionerror!");
       e.printStackTrace();       
      }   
  

6.通过FileWriter来进行写操作

  try {    
       FileWriter fw = new FileWriter("mydata.txt");
       PrintWriter out = new PrintWriter(fw);      
       out.print(“hi,this will be wirte into the file!”);    
       out.close();  
       fw.close();        
       } 
       catch (IOException e) 
       {             
         System.out.println("Uh oh, got an IOException error!");
          e.printStackTrace();       
        }   

评论

1 楼 hnzhoujunmei 2010-08-20