请问：bad file descriptor是什么错误？

[machele]

这是源代码：[code=Java]import java.io.*;
public class FileTest2{
public static void main(String[] args){
FileOutputStream fos = null ;
try{
fos = new FileOutputStream("F:\\java_ex\\abc.txt");
}catch(FileNotFoundException fnf){
fnf.printStackTrace();
}
for(int i='A';i<'Z';i++){
try{
fos.write(i);
fos.close();
}catch(IOException ioe){
ioe.printStackTrace();
}
}
}
}[/code]
这是错误提示：
F:\java_ex>javac FileTest2.java

F:\java_ex>java FileTest
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)
java.io.IOException: Bad file descriptor
at java.io.FileOutputStream.write(Native Method)
at FileTest.main(FileTest.java:38)

F:\java_ex>

[a_nuo]

import java.io.*;
public class  TestFile2{
public static void main(String[] args){
	File f=new File("E:\\javaex\\abc.txt");
	
FileOutputStream fos = null ;
try{
	if(f.exists())
		f.createNewFile();
fos = new FileOutputStream(f);
}catch(Exception fnf){
fnf.printStackTrace();
}
for(int i='A';i <'Z';i++){
try{
fos.write(i);

}catch(IOException ioe){
ioe.printStackTrace();
}}
try {
    fos.close();
}
catch (Exception ex) {
	ex.printStackTrace();
}


}
}

[a_nuo]

你要把所有的字符都输出到文件里面了再调用close（）关闭输出流
你的代码我帮你该了
错在你刚写入一个字符就关闭输出流了

[云上飞翔]

答：错误原因是：fos.close()放在for()循环中产生的。
解决方法：将fos.close()移到循环外面。即：在循环外面，加上：
try{
fos.close();
}catch(IOException e1){e1.printStackTrace();}

[numen_wlm]

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

class TestFile2 {
	public static void main(String[] args) {

		FileOutputStream fos = null;
		try {
			fos = new FileOutputStream("E:\\java_ex\\abc.txt");
			for (int i = 'A'; i < 'Z'; i++) {
				try {
					fos.write(i);
				} catch (IOException ioe) {
					ioe.printStackTrace();					
				}
			}
		} catch (FileNotFoundException fnf) {
			fnf.printStackTrace();			
		}finally{
			try {
				fos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
	}
}

[Shine_Panda]

修改后的代码:
测试成功!!!!!!!!!!

import java.io.*; 
 class  FileTest2{ 

 static void main(String[] args){ 
	FileOutputStream fos = null ; 
	try{ 
		fos = new FileOutputStream("F:\\java_ex\\abc.txt"); 

	 
	    for(int i='A';i <'Z';i++){ 
	
			fos.write(i); 
		
		
		} 
		fos.close(); 
	}catch(FileNotFoundException fe){
		fe.printStackTrace();
	}
	 catch(IOException ioe){ 
			ioe.printStackTrace(); 
	}
	}
	
} 

[KKK2007]

调试通过
Java]import java.io.*;
public class FileTest2{
public static void main(String[] args){
FileOutputStream fos = null ;
try{
fos = new FileOutputStream("F:\\java_ex\\abc.txt");
}catch(FileNotFoundException fnf){
fnf.printStackTrace();
}
for(int i='A';i <'Z';i++){
try{
fos.write(i);

}catch(IOException ioe){
ioe.printStackTrace();
}
finally{fos.close();}
}
}
}

[老紫竹]

[Quote=引用 2 楼 a_nuo 的回复:]
你要把所有的字符都输出到文件里面了再调用close（）关闭输出流
你的代码我帮你该了
错在你刚写入一个字符就关闭输出流了
[/Quote]

这个是第一个发现原因的，支持一个！呵呵！