Re: using TreeMap how to return the Object ?

From:

Jeff Higgins <jeff@invalid.invalid>

Newsgroups:

comp.lang.java.help

Date:

Mon, 01 Jul 2013 10:49:37 -0400

Message-ID:

<kqs4gn$s8l$1@dont-email.me>

On 06/27/2013 11:19 AM, Jeff Higgins wrote:

On 06/27/2013 01:30 AM, moonhkt wrote:

public void process_hosts () {
 File ihost = new File(ifn);
 String delimscfg = "\\s+"; /** multi-space */
 String aline ;
 int i = 0 ;
 try {
 BufferedReader br1 = new BufferedReader(new FileReader(ihost));
 while ((aline = br1.readLine()) != null) {
 String [] tokens = aline.split(delimscfg);
 try {
 if ( ! tokens[0].trim().startsWith("#")) {
 /* System.out.print("-->");
 System.out.print(tokens[0].trim());
 System.out.print(" ");
 System.out.print(tokens[0].trim().substring(0));
 System.out.println("<--"); */

You'll want a (probably immutable) java.util.Comparable key,
or a java.util.Comparator for your key in a java.util.SortedMap.

Why store your key with your value?

                     ipx.put(tokens[0].trim(),new
eleHost(tokens[1].trim(),"x"));
                  }
             } catch (ArrayIndexOutOfBoundsException e) {
                 continue;
             }
           }
        } catch (IOException e) {
           System.out.println(e);
       }
    }

import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.util.Arrays;

import sun.net.util.IPAddressUtil;

/**
 * This class represents an Internet Protocol Version 6 (IPv6)
address.
 * An instance of an IPv6Address consists of an raw IPv6 address
 * (a sixteen element byte array) and has no knowledge of the internal
 * (IPv6) structure of the raw IPv6 address.
 * This class is intended to demonstrate concepts discussed in a
usenet posting.
 * FOR TESTING PURPOSES ONLY -- NOT FOR PRODUCTION
USE
 * @author jeff
 *
 */
public final class IPv6Address implements Comparable<IPv6Address> {

 /**
 * Creates an IPv6Address based on the provided IPv6 raw address.
 * If address is null, or other than sixteen bytes in length,
 * the IPv6 unspecified address is returned.
 * Possible to introduce an IPv6 mapped or compatible IPv4 address
here.
 *
 * @param address a sixteen element byte array (raw IPv6 address)
 * @return an IPv6Address object created from the raw IP address,
 * or the IPv6 unspecified address if address is null or other than
sixteen bytes in length
 */
 public static IPv6Address valueOf(byte[] address) {
 return new IPv6Address(address);
 }

 /**
 * Creates an IPv6Address based on the provided IPv6 address
textual representation.
 * If address is null, or otherwise invalid,
 * the IPv6 unspecified address is returned.
 * IPv6 mapped or compatible IPv4 address are considered invalid
here.
 *
 * @param text representation of an IPv6 address
 * @return an IPv6Address object created from the IPv6 address text,
 * or the IPv6 unspecified address if address is null or invalid per
 * sun.net.util.IPAddressUtil.textToNumericFormatV6(address)
 */
 public static IPv6Address valueOf(String address) {
 return new IPv6Address(address);
 }

 /**
 * The IPv6 raw address stored by this class is in network byte order,
 * the MSB is at index 0 and the LSB is at index 15.
 *
 * @see java.lang.Comparable#compareTo(java.lang.Object)
 */
 @Override
 public int compareTo(IPv6Address address) {
 int comparison = 0;
 for (int i = 0; i < bytes.length; i++) {
 comparison = Byte.compare(bytes[i], address.bytes[i]);
 if (comparison != 0)
 break;
 }
 return comparison;
 }

 /*
 * (non-Javadoc)
 *
 * IDE generated equals method
 *
 * @see java.lang.Object#equals(java.lang.Object)
 */
 @Override
 public boolean equals(Object obj) {
 if (this == obj)
 return true;
 if (obj == null)
 return false;
 if (getClass() != obj.getClass())
 return false;
 IPv6Address other = (IPv6Address) obj;
 if (!Arrays.equals(bytes, other.bytes))
 return false;
 return true;
 }

 /*
 * (non-Javadoc)
 *
 * IDE generated hashCode method
 *
 * @see java.lang.Object#hashCode()
 */
 @Override
 public int hashCode() {
 final int prime = 31;
 int result = 1;
 result = prime * result + Arrays.hashCode(bytes);
 return result;
 }

 /**
 * Converts this IP address to a String. The string returned
 * is of the IPv6 "preferred" form:
 * RFC2373 Section 2.2 Text Representation of Addresses
 * 1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are the
 * hexadecimal values of the eight 16-bit pieces of the address.
 * Examples:
 * <pre>
 FEDC:BA98:7654:3210:FEDC:BA98:7654:3210

 1080:0:0:0:8:800:200C:417A
 * </pre>
 *
 * @return a string representation of this IP address
 * @see java.lang.Object#toString()
 */
 @Override
 public String toString() {

 StringBuilder builder = new StringBuilder();
 CharBuffer buffer = ByteBuffer.wrap(bytes).asCharBuffer();
 while (buffer.hasRemaining()) {
 builder.append(Integer.toHexString(buffer.get()));
 if (buffer.hasRemaining())
 builder.append(":");
 }
 return builder.toString();
 }

 private final byte[] bytes;

 private IPv6Address(byte[] address) {
 bytes = new byte[16];
 if (address != null && address.length == 16)
 System.arraycopy(address, 0, bytes, 0, 16);
 }

 private IPv6Address(String address) {
 @SuppressWarnings("restriction")
 byte[] test = IPAddressUtil.textToNumericFormatV6(address);
 bytes = new byte[16];
 if (test != null && test.length == 16) {
 System.arraycopy(test, 0, bytes, 0, 16);
 }
 }
}