java编程操作心血4

package pc1;

import java.io.*;

class MyLineNumberReader

{

private Reader r;

private int LineNumber;

MyLineNumberReader(Reader r)

{

this.r=r;

}

public String myReadLine()throws IOException

{

LineNumber++;

StringBuilder sb=new StringBuilder();

char ch;

while((ch=(char) r.read())!=-1)

{ 

if(ch=='\r')

continue;

if(ch=='\n')

return sb.toString();

else

sb.append((char)ch);

}

if(sb.length()!=0)

{

return sb.toString();

 

}

return null;

}

public void setLineNumber(int LineNumber)

{

this.LineNumber=LineNumber;

}

public int getLineNumber()

{

return LineNumber;

}

public void myClose()throws  IOException

{

r.close();

}

}

public class MyLineNumberReaderDemo {

 

public static void main(String[] args)throws IOException {

// TODO Auto-generated method stub

FileReader fr=new FileReader("e:\\java_file\\3.txt");

MyLineNumberReader mylrc=new MyLineNumberReader(fr);

 String line=null;

 while((line=mylrc.myReadLine())!=null)

 {

System.out.println(mylrc.getLineNumber()+":"+line);

 }

 mylrc.myClose();

}

 

}

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