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I used FileInputStream class when I was trying to read something from my files reside in SDCard, the codes are as follows: Code:

filepath = "/sdcard/myfile/testFile" FileInputStream fileIn = null;
fileIn = new FileInputStream(filepath); byte [] InBuf = new byte[1024];
fileIn.read(InBuf); Strubg fileContent = new String(InBuf);
fileIn.close();

when I ran my program, android keep reporting null pointer error on my last line:"fileIn.close", I really didn't know the reason

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2 Answers

up vote 0 down vote

Use it like this:

filePath=Environment.getExternalStorageDirectory().getAbsolutePath()+"/myfile/textfile.extenstion"

You must be missing the extension.

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Sorry, I didn't miss any permission. NULL pointer exception couldn't be caused by permission missing. – Terry Yoon Mar 15 '11 at 0:20
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I worked till late last night, finally, I make it work, though I am not sure if it is exact reason. I simply tried the following methods, then no more null pointer report came, 

try  
{
    InputStream fileIn = null;
    filepath = "/sdcard/myfile/testFile";
    fileIn = new BufferedInputStrream(new
    FileInputStream(filepath））;
    byte [] InBuf = new byte[1024];
    fileIn.read(InBuf);
    ...
    ...
    ...  
} catch(Exception e) {
    e.printStackTrace();  
} finally {     
    if(fileIn != null) 
    {       
        try         
        {           
            fileIn.close();         
        } catch(IOException e) {            
            e.printStackTrace();        
        }   
    } 
}

Any way, thank you so much for your help. ^^

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