How to add additional information to the exception object that can be retrieved later?

See more:

Java

IO

exceptions

In Java, I need to get the exact causes whether is FileNotFound or normal IOException. Which I mean if it is Filenotfound exception, do not loose the FilenotFound cause. If it is other IOException, show IOException. No overwritten the causes.
I need to accurately describe the problem,consolidate the exceptions
Important: I need the code block style in this required way.
The original code block must follow in this way, beyond this, no requirement

main(){
try {
readfile();
}catch {
}
}
readfile(){
try{...
}
finally{
if (br1 != null) 
br1.close();
}
}

Above template cause a problem, in finally br1.close could possibly overwrite the FileNotException by generating a IOException.
Here is my complete code:

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

class Hidden {
  public static void main(String args[]){
    Hidden h = new Hidden();
    
    try {
    	System.out.println("Main():: Try Block Starts");
    	h.readFile();
    	System.out.println("Main():: Try Block Ends");
    } catch (FileNotFoundException fne) {
    	System.out.println("Caught FileNotFoundException!");
    	System.out.println(fne.getMessage());
    	  //fne.printStackTrace();
    } catch (IOException ioe) {
    	System.out.println("Caught IOException!");
  	  	System.out.println(ioe.getCause());
  	  //ioe.printStackTrace();
    }
  }
  
  public void readFile() throws FileNotFoundException,IOException {
	  BufferedReader br1 = null;
      FileReader fr = null;
    
      try {
    	  System.out.println("readFile():: Try Block Starts."); 
    	  fr = new FileReader("data1.fil");                       //1
    	  br1 = new BufferedReader(fr);
    	 // int i = br1.read();                                     //2
    	  //Other code...
    	  System.out.println("readFile():: Try Block Ends.");                                   //4
     } catch (IOException ioe){
    	 System.out.println("readFile():: Catch Block Starts.");
    	 if(ioe.getCause() instanceof FileNotFoundException);
    	  throw new FileNotFoundException("data1.fil is not exisited");
    }
     finally {
    	System.out.println("readFile():: Finally Block Starts");
    	if (br1 != null) {
    		br1.close();
    	}else {
    		//throw new IOException();
        }
    	System.out.println("readFile():: Finally Block Ends");
    }
  }
}