ipaccess.java

来自「一款Java实现的HTTP代理服务器」· Java 代码 · 共 74 行

package rabbit.util;

import java.net.InetAddress;

/** A class to handle access to ip ranges.
 *
 * @author <a href="mailto:[e-mail]">Robert Olofsson</a>
 */
public class IPAccess {
    private long lowip;          // lowest ip in range
    private long highip;         // highest ip in range

    /** Create a new IPAccess with given ip-range.
     * @param lowip the lowest ip in the range
     * @param highip the highest ip in the range
     */
    public IPAccess (InetAddress lowip, InetAddress highip) {
	if (lowip == null || highip == null)
	    return;
	setup (lowip, highip);
    }

    /** transform to suitable variabletypes
     */
    private void setup (InetAddress lowipa, InetAddress highipa) {
	lowip = getLongFromIP (lowipa);
	highip = getLongFromIP (highipa);

	if (lowip > highip) {
	    long t = lowip;
	    lowip = highip;
	    highip = t;
	} 
    }
  
    /** make an long from the ip so we can do simple test later on
     */
    private long getLongFromIP (InetAddress ia) {
	byte[] address = ia.getAddress ();
	long ret = 0;
	for (int i = 0; i < address.length; i++) {
	    ret <<= 8;
	    long a = address[i] & 0xff; // byte is signed, signextension is evil..
	    ret |= a;
	}
	return ret;
    }

    /** check if a given ip is in this accessrange
     * @param ia the ip we are testing.
     * @return true if ia is in the range (inclusive), false otherwise 
     */ 
    public boolean inrange (InetAddress ia) {
	long check = getLongFromIP (ia);
	return (check >= lowip && check <= highip);
    }
    
    /** get the string representation of this access.
     */
    public String toString () {
	String low = getIP (lowip);
	String high = getIP (highip);
	
	return "" + low + "\t" + high;
    }
    
    private String getIP (long ip) {
	return  "" + (ip>>24) + "." +
	    ((ip>>16)&0xff) + "." +
	    ((ip>>8)&0xff) + "." +
	    (ip&0xff);
    }
}