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2010-06-01T06:00:48Z

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в 18:01, 31 мая 2010

2010-05-31T18:01:43Z

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== Find duplication ==



<source lang="java">

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
public class MatchDuplicateWords {
public static void main(String args[]) {
hasDuplicate("pizza pizza");
hasDuplicate("Faster pussycat kill kill");
hasDuplicate("The mayor of of simpleton");
hasDuplicate("Never Never Never Never Never");
hasDuplicate("222 2222");
hasDuplicate("sara sarah");
hasDuplicate("Faster pussycat kill, kill");
hasDuplicate(". .");
}
public static boolean hasDuplicate(String phrase) {
boolean retval = false;
String duplicatePattern = "\\b(\\w+) \\1\\b";
Pattern p = null;
try {
p = Pattern.rupile(duplicatePattern);
} catch (PatternSyntaxException pex) {
pex.printStackTrace();
System.exit(0);
}
int matches = 0;
Matcher m = p.matcher(phrase);
String val = null;
while (m.find()) {
retval = true;
val = ":" + m.group() + ":";
System.out.println(val);
matches++;
}
String msg = " NO MATCH: pattern:" + phrase
+ "\r\n regex: " + duplicatePattern;
if (retval) {
msg = " MATCH : pattern:" + phrase + "\r\n regex: "
+ duplicatePattern;
}
System.out.println(msg + "\r\n");
return retval;
}
}

</source>



== Perform credit card validations. ==



<source lang="java">

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

/**
* Perform credit card validations.
* 
* By default, all supported card types are allowed. You can specify which
* cards should pass validation by configuring the validation options. For
* example, <code>CreditCardValidator ccv = new CreditCardValidator(CreditCardValidator.AMEX + CreditCardValidator.VISA);</code>
* configures the validator to only pass American Express and Visa cards.
* If a card type is not directly supported by this class, you can implement
* the CreditCardType interface and pass an instance into the
* <code>addAllowedCardType</code> method.
* 
* For a similar implementation in Perl, reference Sean M. Burke"s
* .
*
* @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
* @since Validator 1.1
*/
public class CreditCardValidator {
/**
* Option specifying that no cards are allowed. This is useful if
* you want only custom card types to validate so you turn off the
* default cards with this option.
* 
* <pre>
* CreditCardValidator v = new CreditCardValidator(CreditCardValidator.NONE);
* v.addAllowedCardType(customType);
* v.isValid(aCardNumber);
* </pre>
* @since Validator 1.1.2
*/
public static final int NONE = 0;
/**
* Option specifying that American Express cards are allowed.
*/
public static final int AMEX = 1 << 0;
/**
* Option specifying that Visa cards are allowed.
*/
public static final int VISA = 1 << 1;
/**
* Option specifying that Mastercard cards are allowed.
*/
public static final int MASTERCARD = 1 << 2;
/**
* Option specifying that Discover cards are allowed.
*/
public static final int DISCOVER = 1 << 3;

/**
* The CreditCardTypes that are allowed to pass validation.
*/
private Collection cardTypes = new ArrayList();
/**
* Create a new CreditCardValidator with default options.
*/
public CreditCardValidator() {
this(AMEX + VISA + MASTERCARD + DISCOVER);
}
/**
* Create a new CreditCardValidator with the specified options.
* @param options Pass in
* CreditCardValidator.VISA + CreditCardValidator.AMEX to specify that
* those are the only valid card types.
*/
public CreditCardValidator(int options) {
super();
Flags f = new Flags(options);
if (f.isOn(VISA)) {
this.cardTypes.add(new Visa());
}
if (f.isOn(AMEX)) {
this.cardTypes.add(new Amex());
}
if (f.isOn(MASTERCARD)) {
this.cardTypes.add(new Mastercard());
}
if (f.isOn(DISCOVER)) {
this.cardTypes.add(new Discover());
}
}
/**
* Checks if the field is a valid credit card number.
* @param card The card number to validate.
* @return Whether the card number is valid.
*/
public boolean isValid(String card) {
if ((card == null) || (card.length() < 13) || (card.length() > 19)) {
return false;
}
if (!this.luhnCheck(card)) {
return false;
}

Iterator types = this.cardTypes.iterator();
while (types.hasNext()) {
CreditCardType type = (CreditCardType) types.next();
if (type.matches(card)) {
return true;
}
}
return false;
}

/**
* Add an allowed CreditCardType that participates in the card
* validation algorithm.
* @param type The type that is now allowed to pass validation.
* @since Validator 1.1.2
*/
public void addAllowedCardType(CreditCardType type){
this.cardTypes.add(type);
}
/**
* Checks for a valid credit card number.
* @param cardNumber Credit Card Number.
* @return Whether the card number passes the luhnCheck.
*/
protected boolean luhnCheck(String cardNumber) {
// number must be validated as 0..9 numeric first!!
int digits = cardNumber.length();
int oddOrEven = digits & 1;
long sum = 0;
for (int count = 0; count < digits; count++) {
int digit = 0;
try {
digit = Integer.parseInt(cardNumber.charAt(count) + "");
} catch(NumberFormatException e) {
return false;
}
if (((count & 1) ^ oddOrEven) == 0) { // not
digit *= 2;
if (digit > 9) {
digit -= 9;
}
}
sum += digit;
}
return (sum == 0) ? false : (sum % 10 == 0);
}

/**
* CreditCardType implementations define how validation is performed
* for one type/brand of credit card.
* @since Validator 1.1.2
*/
public interface CreditCardType {

/**
* Returns true if the card number matches this type of credit
* card. Note that this method is not responsible
* for analyzing the general form of the card number because
* <code>CreditCardValidator</code> performs those checks before
* calling this method. It is generally only required to valid the
* length and prefix of the number to determine if it"s the correct
* type.
* @param card The card number, never null.
* @return true if the number matches.
*/
boolean matches(String card);

}

/**
* Change to support Visa Carte Blue used in France
* has been removed - see Bug 35926
*/
private class Visa implements CreditCardType {
private static final String PREFIX = "4";
public boolean matches(String card) {
return (
card.substring(0, 1).equals(PREFIX)
&& (card.length() == 13 || card.length() == 16));
}
}

private class Amex implements CreditCardType {
private static final String PREFIX = "34,37,";
public boolean matches(String card) {
String prefix2 = card.substring(0, 2) + ",";
return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 15));
}
}

private class Discover implements CreditCardType {
private static final String PREFIX = "6011";
public boolean matches(String card) {
return (card.substring(0, 4).equals(PREFIX) && (card.length() == 16));
}
}

private class Mastercard implements CreditCardType {
private static final String PREFIX = "51,52,53,54,55,";
public boolean matches(String card) {
String prefix2 = card.substring(0, 2) + ",";
return ((PREFIX.indexOf(prefix2) != -1) && (card.length() == 16));
}
}
}

/**
* Represents a collection of 64 boolean (on/off) flags. Individual flags
* are represented by powers of 2. For example, 
* Flag 1 = 1 
* Flag 2 = 2 
* Flag 3 = 4 
* Flag 4 = 8 
* or using shift operator to make numbering easier: 
* Flag 1 = 1 << 0 
* Flag 2 = 1 << 1 
* Flag 3 = 1 << 2 
* Flag 4 = 1 << 3 
*
* 
* There cannot be a flag with a value of 3 because that represents Flag 1
* and Flag 2 both being on/true.
* 
*
* @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
*/
class Flags implements Serializable {
/**
* Represents the current flag state.
*/
private long flags = 0;
/**
* Create a new Flags object.
*/
public Flags() {
super();
}
/**
* Initialize a new Flags object with the given flags.
*
* @param flags collection of boolean flags to represent.
*/
public Flags(long flags) {
super();
this.flags = flags;
}
/**
* Returns the current flags.
*
* @return collection of boolean flags represented.
*/
public long getFlags() {
return this.flags;
}
/**
* Tests whether the given flag is on. If the flag is not a power of 2
* (ie. 3) this tests whether the combination of flags is on.
*
* @param flag Flag value to check.
*
* @return whether the specified flag value is on.
*/
public boolean isOn(long flag) {
return (this.flags & flag) > 0;
}
/**
* Tests whether the given flag is off. If the flag is not a power of 2
* (ie. 3) this tests whether the combination of flags is off.
*
* @param flag Flag value to check.
*
* @return whether the specified flag value is off.
*/
public boolean isOff(long flag) {
return (this.flags & flag) == 0;
}
/**
* Turns on the given flag. If the flag is not a power of 2 (ie. 3) this
* turns on multiple flags.
*
* @param flag Flag value to turn on.
*/
public void turnOn(long flag) {
this.flags |= flag;
}
/**
* Turns off the given flag. If the flag is not a power of 2 (ie. 3) this
* turns off multiple flags.
*
* @param flag Flag value to turn off.
*/
public void turnOff(long flag) {
this.flags &= ~flag;
}
/**
* Turn off all flags.
*/
public void turnOffAll() {
this.flags = 0;
}

/**
* Turn off all flags. This is a synonym for <code>turnOffAll()</code>.
* @since Validator 1.1.1
*/
public void clear() {
this.flags = 0;
}
/**
* Turn on all 64 flags.
*/
public void turnOnAll() {
this.flags = Long.MAX_VALUE;
}
/**
* Clone this Flags object.
*
* @return a copy of this object.
* @see java.lang.Object#clone()
*/
public Object clone() {
try {
return super.clone();
} catch(CloneNotSupportedException e) {
throw new RuntimeException("Couldn"t clone Flags object.");
}
}
/**
* Tests if two Flags objects are in the same state.
* @param obj object being tested
* @see java.lang.Object#equals(java.lang.Object)
*
* @return whether the objects are equal.
*/
public boolean equals(Object obj) {
if (!(obj instanceof Flags)) {
return false;
}
if (obj == this) {
return true;
}
Flags f = (Flags) obj;
return this.flags == f.flags;
}
/**
* The hash code is based on the current state of the flags.
* @see java.lang.Object#hashCode()
*
* @return the hash code for this object.
*/
public int hashCode() {
return (int) this.flags;
}
/**
* Returns a 64 length String with the first flag on the right and the
* 64th flag on the left. A 1 indicates the flag is on, a 0 means it"s
* off.
*
* @return string representation of this object.
*/
public String toString() {
StringBuffer bin = new StringBuffer(Long.toBinaryString(this.flags));
for (int i = 64 - bin.length(); i > 0; i--) {
bin.insert(0, "0");
}
return bin.toString();
}
}

</source>



== Simplest validation ==



<source lang="java">

public class ValidationTest {
public static void main(String[] args) {
String candidate = "I love Java and jexp";
String pattern = "Java \\d";
System.out.println(candidate.matches(pattern));
}
}

</source>



== Validation with Pattern and Matcher ==



<source lang="java">

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
public class ValidationTestWithPatternAndMatcher {
public static void main(String args[]) {
Pattern p = null;
try {
p = Pattern.rupile("Java \\d");
} catch (PatternSyntaxException pex) {
pex.printStackTrace();
System.exit(0);
}
String candidate = "I love Java 5";
Matcher m = p.matcher(candidate);
System.out.println("result=" + m.find());
}
}

</source>

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Admin: 1 версия

в 18:01, 31 мая 2010