Java/Regular Expressions/Validation — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Текущая версия на 09:00, 1 июня 2010
Содержание
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,CreditCardValidator ccv = new CreditCardValidator(CreditCardValidator.AMEX + CreditCardValidator.VISA);
* 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
* addAllowedCardType
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. **
* CreditCardValidator v = new CreditCardValidator(CreditCardValidator.NONE); * v.addAllowedCardType(customType); * v.isValid(aCardNumber); *
* @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
* CreditCardValidator
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 turnOffAll()
.
* @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>