新手学写文件时的一个问题
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
[解决办法]
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());
[解决办法]
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! ");
}
}
}
