Java/CoreJava/v2ch06/textFormat/IPAddressFormatter.java at master · mthli/Java · GitHub

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package textFormat;

import java.text.*;

import java.util.*;

import javax.swing.text.*;

/**

* A formatter for 4-byte IP addresses of the form a.b.c.d

public class IPAddressFormatter extends DefaultFormatter

{

public String valueToString(Object value) throws ParseException

{

if (!(value instanceof byte[])) throw new ParseException("Not a byte[]", 0);

byte[] a = (byte[]) value;

if (a.length != 4) throw new ParseException("Length != 4", 0);

StringBuilder builder = new StringBuilder();

for (int i = 0; i < 4; i++)

{

int b = a[i];

if (b < 0) b += 256;

builder.append(String.valueOf(b));

if (i < 3) builder.append('.');

}

return builder.toString();

}

public Object stringToValue(String text) throws ParseException

{

StringTokenizer tokenizer = new StringTokenizer(text, ".");

byte[] a = new byte[4];

for (int i = 0; i < 4; i++)

{

int b = 0;

if (!tokenizer.hasMoreTokens()) throw new ParseException("Too few bytes", 0);

try

{

b = Integer.parseInt(tokenizer.nextToken());

}

catch (NumberFormatException e)

{

throw new ParseException("Not an integer", 0);

}

if (b < 0 || b >= 256) throw new ParseException("Byte out of range", 0);

a[i] = (byte) b;

}

if (tokenizer.hasMoreTokens()) throw new ParseException("Too many bytes", 0);

return a;

}

Java/CoreJava/v2ch06/textFormat/IPAddressFormatter.java at master · mthli/Java · GitHub

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