新手学写文件时的一个问题

Question

package a;import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.BufferedWriter;import java.io.IOException;public class leilei
{
    public static void main(String args[])
    {
        try{
            File wenjian=new File(args[0]);
            File wenjian2=new File(args[1]);
            
            if (!wenjian.exists())
            {
                System.out.println("文件不存在!");
                return;
            }
            
            else if(wenjian.length()==0)
            {
                System.out.println("文件长度为0！");
                return;
            }
            
            FileReader duqu=new FileReader(wenjian);
            BufferedReader duqua =new BufferedReader(duqu);
            
            FileWriter xieru=new FileWriter(args[1]);
            BufferedWriter xierua =new BufferedWriter(xieru);
            
            String zifu=duqua.readLine();
            
            while(zifu!=null)
            {
                xierua.write(zifu,0,zifu.length());
                System.out.println("已写入:"+zifu);
                zifu=duqua.readLine();
            }
            
            duqua.close();
            duqu.close();
            
            xieru.close();
            xierua.close();
        
        }catch(IOException e)
        {
            System.out.println("出错!");
        }catch(Exception a)
        {
            System.out.println("请输入参数!");
        }        
        
    }
}上面这些代码总是出错！  IOException 异常被丢出来了 而且也不能把读出来的文件内容写进另一个文件

Answer 1

BufferedWriter xierua =new BufferedWriter(xieru);
xierua.close();
这两句去掉xierua.write(zifu,0,zifu.length());
这句改成xieru.write(zifu,0,zifu.length());

Answer 2

给楼主调试能过了。楼主上面xieru.close();xierua.close();这两句关的时候应先关xierua.close();然后再关xieru.close();
import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.BufferedWriter;import java.io.IOException;public class leilei
{
    public static void main(String args[])
    {
        try{
            File wenjian=new File(args[0]);
            File wenjian2=new File(args[1]);
            
            if (!wenjian.exists())
            {
                System.out.println("文件不存在!");
                return;
            }
            
            else if(wenjian.length()==0)
            {
                System.out.println("文件长度为0！");
                return;
            }
            
            FileReader duqu=new FileReader(wenjian);
            BufferedReader duqua =new BufferedReader(duqu);
            
            FileWriter xieru=new FileWriter(args[1]);
            BufferedWriter xierua =new BufferedWriter(xieru);
            
            String zifu=duqua.readLine();
            
            while(zifu!=null)
            {
                xierua.write(zifu,0,zifu.length());
                System.out.println("已写入:"+zifu);
                zifu=duqua.readLine();
            }
            
            duqua.close();
            duqu.close();
            
            xierua.close();
            xieru.close();
           
        
        }catch(IOException e)
        {
            System.out.println("出错!");
        }catch(Exception a)
        {
            System.out.println("请输入参数!");
        }        
        
    }
}

Answer 3

汗 粗心了 请问一下 BufferedWriter和FileWriter有啥不同哩？ 哪个比较好？谢谢！