How to browse a file and extract its contents

Question

i want to browse a file and extract its contents.My code is given below but its not working .Can anybody help me please
JFileChooser fc = new JFileChooser();
          int returnVal = fc.showOpenDialog(jfrm);
          if (returnVal == JFileChooser.APPROVE_OPTION)
          File file = fc.getSelectedFile();
          //This is where a real application would open the file.
          fileName=file.getName();
          //This is a file function to extract data from a file.
          //It reads data from a file that can be viewed on cmd
          jlab3.setText(fileName);
          try
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(fileName);
// Convert our input stream to a
// DataInputStream
          DataInputStream in =new DataInputStream(fstream);
// Continue to read lines while
// there are still some left to read
// while (in.available() !=0)
// Print file line to screen
          fileName1=in.readLine();
          jlab3.setText(fileName1);
          in.close();
catch (Exception e)
          System.err.println("File input error");
          }

Answer 1

JFileChooser fc = new JFileChooser();
int returnVal = fc.showOpenDialog(jfrm);
if (returnVal == JFileChooser.APPROVE_OPTION)
File file = fc.getSelectedFile();
//This is where a real application would open the file.
fileName=file.getName();
//This is a file function to extract data from a file.
//It reads data from a file that can be viewed on cmd
jlab3.setText(fileName);
try
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream(fileName);
// Convert our input stream to a
// DataInputStream
DataInputStream in =new DataInputStream(fstream);
// Continue to read lines while
// there are still some left to read
// while (in.available() !=0)
// Print file line to screenHere you are reading the first line of the file
  fileName1=in.readLine();
//}and here you are displaying the line in a (I suppose) JLabel. A JLabel is not very suitable for displaying a file content, except is the file contain few characters !!!
jlab3.setText(fileName1);
in.close();
catch (Exception e)
System.err.println("File input error");
}If you want to read the complete file content you must uncomment lines inside while instruction, like this
while (in.available() > 0) {  // I prefer to test in.available like this, instead of !=
  // append text to a StringBuffer (variable named sb here) or directly in a textarea.
  sb.append(in.readLine());
...