Create a byte array from a image file

[ram ragu]

Hello,
I am totally new to java and I just wanted to know how to create a byte array from an image file i.e i have a test.gif on my local drive
(c:/test.gif)
It might be simple .. but i just started learning java.. but need to do this rightaway ..
let me know.

[Jason Ford]

If you want to create a byte array from a file, you just need to read in the file and store the result to an array:

File myFile = new File( "test.gif" );
BufferedReader br = new BufferedReader( myFile ); 
// Look out for big files...
// ...this sloppy cast won't work!
char[] fileContents = new char[ (int)myFile.length() ];
        
try {
    br.read( fileContents, 0, (int)myFile.length() );
}
catch( IOException e ) {
    ...do some cool exception handling stuff
}

If you really want a byte array instead of the char array, create a String with the char array and use the getBytes method on the String.
Unless I'm missing something...
HTH,
Jason

[hennie louw]

// Look out for big files...
// ...this sloppy cast won't work!
char[] fileContents = new char[ (int)myFile.length() ];
        
try {
    br.read( fileContents, 0, (int)myFile.length() );
}
catch( IOException e ) {
    ...do some cool exception handling stuff
}

That might work but you can also try this

 
public protected byte[] real;
public protected byte[] dummy;
public void readFile () {
   File myFile = new File( "test.gif" );
   FileInputStream fIS = new FileInputStreammyFile ); 
   //so we can read 1k at a time
   byte[] now = new byte[1024];
   // just to start the loop 
   now[0] = (byte)1;
   while (now[0] != null) {
       fIS.read(now);
       this.addToMainArray(now); 
    } // end of loop 
} // end of readFile 
public void addToMainArray(byte[] toAdd) {
this.dummy = null;
this.dummy = new byte[this.real.length];
System.arraycopy(this.real, 0, this.dummy, 0, this.real.length - 1);
this.real = null; 
this.real = new byte[(this.dummy.length + toAdd.length)];
System.arraycopy(this.dummy , 0, this.real, 0, this.dummy.length - 1);
System.arraycopy(toAdd, 0, this.real, this.dummy.length, toAdd.length - 1); 
}

I'm just not sure if {array}.length value is the length of the array or the number of the last reffrence , but goo luck