Hashing

hashing.java

// Example:
//
//  System.out.println(Hasher.sha1("hello world"));      // prints: 2aae6c35c94fcfb415dbe95f408b9ce91ee846ed
//  System.out.println(Hasher.sha1AsInt("hello world")); // prints: 896314922

import java.nio.charset.*;
import com.google.common.hash.*;

class Hasher {
  public static String sha1(String input) {
    // See https://github.com/google/guava/wiki/HashingExplained
    HashFunction hf = Hashing.sha1();
    HashCode hc = hf.newHasher()
      .putString(input, StandardCharsets.UTF_8)
      .hash();
    return hc.toString();
  }
  
  public static int sha1AsInt(String input) {
    HashFunction hf = Hashing.sha1();
    HashCode hc = hf.newHasher()
      .putString(input, StandardCharsets.UTF_8)
      .hash();
    return hc.asInt();
  }
}