I need to create a Unique Integer from a String in Java so that collision chances are pretty less.
Is there any way, we can create a integer in Java which is always Unique for the same string?
I have to store the lacks of string in database, so i want to convert into hashcode for less retrieving time where I fire SELECT query..
"always unique"? No.
What you're talking about is basically hashing and, unless your strings have no more information content (i.e., bits) than your integers, you cannot guarantee uniqueness.
The best you can hope for is some reasonably balanced loading factor and there are many general purpose hashing functions available on the net.
Java's Object class actually provides a .hashCode() method which most sub-classes can override if they want different behaviour.
And, in fact, Java's String class does exactly that.
So you can simply do something like:
String str = "My hovercraft is full of eels";
int code = str.hashCode();
See this example
import java.io.*;
public class Test {
public static void main(String args[]) {
String Str = new String("Welcome to Tutorialspoint.com");
System.out.println("Hashcode for Str :" + Str.hashCode() );
}
}
If srring will be same then it will produce the same hash code Reference.
You can also check it How to generate a unique hash code for string input in android...?
loop the string and get one char from string and get the ascii of each charter and combine the ascii . it will give unique integer. below is the code how to get ascii from a character.
String name = "admin";
char character = name.charAt(0); // This gives the character 'a'
int ascii = (int) character; // ascii is now 97.