读写某个文件
package com.huawei.test;

import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.LineNumberReader;

public class WriteFile {
public static void main(String[] args) throws IOException
{
FileReader fr=new FileReader("C:\\Users\\Administrator\\Desktop\\Task.java");
BufferedWriter bwf = null;
LineNumberReader lnr=new LineNumberReader(fr);
String line=null;

lnr.setLineNumber(0);

//从十开始 定义在循环外

while((line=lnr.readLine())!=null)
{
bwf= new BufferedWriter(new FileWriter("E:\\Task.java",true));
//bwf= new BufferedWriter(new FileWriter("f:\\Task.java"));
System.out.println(lnr.getLineNumber()+":"+line);
bwf.write(line+"\n");
// if(lnr.getLineNumber()==15){
// break;
// }
bwf.flush();
}
lnr.close();
bwf.close();
}
}