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How to find a character in a file (which line and which column) which causes sun.io.MalformedException thrown

Posted on 2006-11-27
13
428 Views
Last Modified: 2008-02-01
I have a piece of code inside try block like the following:

BufferedReader reader = new BufferedReader (new InputStreamReader(new FileInputStream(pFile), "UTF-8"));

text = reader.reader.readLine();  line 1

while(text != null)
{
      text = reader.readLine();
}


//notes: text variable has been defined and pFile is passed from function call.

When I run the piece of code, it always throws sun.io.MalformedException at line 1.

It is very possible that it exists invalid character in pFile.  Is there any way to change the piece code to find which line and which column the invalid character is located so that I can just correct it in pFile.

I did the following changes to find which line but didn't work (this change will not find which column the invalid character is located). It always print linenumber is 1. It sounds that the whole file has only one line after creating reader object using UTF-8

int linenumber = 1;
text = reader.readerLine();

while(text != null)
{
      linenumber++;
      text = reader.readLine();
}

Thanks for the help
0
Comment
Question by:cplusplus030999
13 Comments
 
LVL 12

Expert Comment

by:enachemc
ID: 18019846
since MalformedException does not exist,  you are probably reffering to MalformedURLException. This would be caused by the value of pFile variable. Which is the real value of the variable.
0
 

Author Comment

by:cplusplus030999
ID: 18019887
sun.io.MalformedException is a famous exception. Like I said, the exception is thrown from line 1. pFile is File object without any problem. I have tried other good file and it works
0
 
LVL 10

Expert Comment

by:ADSLMark
ID: 18019902
It would be nice to see the value of pFile and also the precise error message.

Mark
0
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Author Comment

by:cplusplus030999
ID: 18020078
pFile = new File("C\:\\temp\\real_file.html");

C: is c drive, temp is folder and real_file.html is file name. They will exist.

sun.io.MalformedException is just like NullPointerException. If you want to get precise error message, you will be disppointed since it is null.

0
 
LVL 10

Expert Comment

by:ADSLMark
ID: 18020090
C\: ?? shouldn't that be C:\

Mark
0
 
LVL 10

Expert Comment

by:ADSLMark
ID: 18020098
I mean:

pFile = new File("C:\\temp\\real_file.html");

: does not need escaping does it?

Mark

0
 
LVL 10

Expert Comment

by:ADSLMark
ID: 18020117
Well i could have posted this all in one post but you should use the pathSeperator from the File class:

http://java.sun.com/j2se/1.4.2/docs/api/java/io/File.html

static String pathSeparator
          The system-dependent path-separator character, represented as a string for convenience.
static char pathSeparatorChar
          The system-dependent path-separator character.
static String separator
          The system-dependent default name-separator character, represented as a string for convenience.
static char separatorChar
          The system-dependent default name-separator character.

Mark
0
 

Author Comment

by:cplusplus030999
ID: 18020239
ADSLMark,


pFile = new File("C:\\temp\\real_file.html");
and pFile = new File("C\:\\temp\\real_file.html") both work. Like I said, the file name is not an issue. I have the folder name in property file. It works for other files. Please don't take too much time on this. pFile is absolutely valid File object. Thanks.
0
 
LVL 10

Accepted Solution

by:
ADSLMark earned 125 total points
ID: 18020425
Ok, i understand.

I made my own utf-8 file with some japanese/chinese characters. I dragged it into a hex editor and i saw 0x0D 0x0A (which is carriage return and new line) in there, so i copied the code above and tested if i received multiple lines or just one and i received more lines. So i guess the error (which i obvious cannot reproduce since i do not have the file) seems to be on line 1.

I think the file is not accessible for outsiders?

Mark
0
 

Author Comment

by:cplusplus030999
ID: 18020761
Since BufferedStream allows UTF-8 transferred but why readLine() can not reacognize that. Obviously readLine is only reading one line. If BufferedStream is UTF-8, it should know that
0
 
LVL 86

Assisted Solution

by:CEHJ
CEHJ earned 125 total points
ID: 18022433
Use a http://java.sun.com/j2se/1.5.0/docs/api/java/nio/charset/CharsetDecoder.html

It will allow you to trap encoding exceptions in detail
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