utilidades.java

java 实现的P2P Chord算法。chord算法是结构式的P2P搜索与管理协议

package org.mikel.jchord;
/*
 * Utilidades.java
 *
 * Created on 23 de marzo de 2005, 12:34
 */
import java.math.*;
import java.security.*;
import java.text.*;
import java.math.*;
/**
 *
 * @author mikel
 */
public class Utilidades {
    
    BigInteger a;
    Integer b;
    
    public static BigInteger generarSHA1(String key){
        try{
            MessageDigest md = MessageDigest.getInstance("SHA-1");
            byte[] hashMsg = md.digest(key.toString().getBytes());
            return (new BigInteger(hashMsg)).abs();
        } catch(Exception e){}
        return null;
    }
    
    public static boolean entre(final BigInteger candidato, final BigInteger a, final BigInteger b, final boolean inclusivo) {
        if (b.compareTo(a) >0 ){ // b>a
            return(candidato.compareTo(a)>0 && (candidato.compareTo(b)<0 || candidato.compareTo(b)<=0 && inclusivo));
        } else { //b<=a
            return candidato.compareTo(a)>0 || (candidato.compareTo(b)<0 || candidato.compareTo(b)<=0 && inclusivo);
        }
    }
    
    public static boolean between(final BigInteger _candidate, final BigInteger _b1, final BigInteger _b2, final boolean _inclusive) {
        if (_inclusive && (_candidate.equals(_b1) || _candidate.equals(_b2)))
            return true;
        
        return _candidate.compareTo(_b2) == -1 && _candidate.compareTo(_b1) == 1;
    }
    
    
    
    public static boolean bigIntegerMayorQue(BigInteger s1, BigInteger s2){
        return s1.compareTo(s2) > 0;
    }
    public static boolean bigIntegerMenorQue(BigInteger s1, BigInteger s2){
        return s1.compareTo(s2) < 0;
    }
    public static boolean bigIntegerIgualQue(BigInteger s1, BigInteger s2){
        return s1.compareTo(s2) == 0;    }
    
    public static boolean bigIntegerNoIgualQue(BigInteger s1, BigInteger s2){
        return s1.compareTo(s2) != 0;
    }
    public static boolean bigIntegerMayorOIgualQue(BigInteger s1, BigInteger s2){
        return s1.compareTo(s2) >= 0;
    }
    public static boolean bigIntegerMenorOIgualQue(BigInteger s1, BigInteger s2){
        
        return s1.compareTo(s2) <= 0;
    }
    
}