Write / read files to RAM memory

Question

Dear all,
I want to write a text file to RAM memory and after read it from RAM memory.
Why? Because, I want to read my text files quickly, in short time.
if I use default method for reading files it take long time for reading the file and for write the file.
But, if I use write / read files to RAM memory, I can read my files quickly and read my files from RAM for processing and write my files to HDD.
Can you help me?
I searched on the Internet this problem and I did not find any one solution.
From my searching on the Internet, I understand that Java can not do that.

Answer 1

The problem with this program is that it load 1 minutes, but I want to load a second.
Here is my java code:
import java.io.*;
public class File {
public static void main(String[] args) {
// Start to reading the file
      try{
    FileInputStream fstream1 = new FileInputStream("big.txt");
    DataInputStream in = new DataInputStream(fstream1);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
    String strLine;
    while ((strLine = br.readLine()) != null)   {
// Start to replacing method
    String strreplace = "%";
    String result = strLine.replaceAll("a", strreplace);
// End of replacing method
// Start to writing to file
      try{
    FileWriter fstream2 = new FileWriter("out.txt", true);
        BufferedWriter out = new BufferedWriter(fstream2);
    out.write(result); // Write to file the result
    out.close();
    }catch (Exception e){
      System.err.println("Error: " + e.getMessage());
// End of writing to file
    in.close();
    }catch (Exception e){
      System.err.println("Error: " + e.getMessage());
// End of reading from file
} // Here is the end...Please to do the following steps:
1. Copy my code;
2. Download text file from: [http://norvig.com/big.txt|http://norvig.com/big.txt]
3. Open the text editor and select all text (Ctr+A) and dublicate the text 10 times for creating a big text file (30-40 MB);
4. As a java developer, You know what to do next.
I'm waiting your solution.
Thanks in advance!