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Posted to dev@commons.apache.org by sc...@apache.org on 2002/12/29 22:35:04 UTC
cvs commit: jakarta-commons/lang/src/java/org/apache/commons/lang/util IdentifierUtils.java
scolebourne 2002/12/29 13:35:04
Modified: lang/src/test/org/apache/commons/lang/util
UtilTestSuite.java
Added: lang/src/test/org/apache/commons/lang/util
IdentifierUtilsTest.java
lang/src/java/org/apache/commons/lang/util
IdentifierUtils.java
Log:
Add Identifier generators to Lang from Util
Revision Changes Path
1.2 +2 -1 jakarta-commons/lang/src/test/org/apache/commons/lang/util/UtilTestSuite.java
Index: UtilTestSuite.java
===================================================================
RCS file: /home/cvs/jakarta-commons/lang/src/test/org/apache/commons/lang/util/UtilTestSuite.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- UtilTestSuite.java 18 Dec 2002 02:50:36 -0000 1.1
+++ UtilTestSuite.java 29 Dec 2002 21:35:03 -0000 1.2
@@ -86,6 +86,7 @@
TestSuite suite = new TestSuite();
suite.setName("Commons-Lang-Util Tests");
suite.addTest(BitFieldTest.suite());
+ suite.addTest(IdentifierUtilsTest.suite());
return suite;
}
}
1.1 jakarta-commons/lang/src/test/org/apache/commons/lang/util/IdentifierUtilsTest.java
Index: IdentifierUtilsTest.java
===================================================================
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.commons.lang.util;
import junit.framework.Test;
import junit.framework.TestSuite;
import org.apache.commons.lang.functor.Factory;
import org.apache.commons.lang.functor.FactoryException;
/**
* Tests the org.apache.commons.lang.util.IdentifierUtils class.
*
* @author Stephen Colebourne
* @version $Id: IdentifierUtilsTest.java,v 1.1 2002/12/29 21:35:03 scolebourne Exp $
*/
public class IdentifierUtilsTest extends junit.framework.TestCase {
/**
* Construct
*/
public IdentifierUtilsTest(String name) {
super(name);
}
/**
* Return class aa a test suite.
*/
public static Test suite() {
TestSuite suite = new TestSuite(IdentifierUtilsTest.class);
suite.setName("IdentifierUtils Tests");
return suite;
}
//--------------------------------------------------------------------------
public void testLongIncrementing() {
Factory f = IdentifierUtils.LONG_IDENTIFIER_FACTORY;
assertEquals(new Long(0), f.create());
assertEquals(new Long(1), f.create());
assertEquals(new Long(2), f.create());
assertEquals(new Long(3), f.create());
assertEquals(new Long(4), IdentifierUtils.nextLongIdentifier());
assertEquals(new Long(5), f.create());
assertEquals(new Long(6), IdentifierUtils.nextLongIdentifier());
assertEquals(new Long(7), IdentifierUtils.nextLongIdentifier());
}
public void testLongIncrementingNoArgs() {
Factory f = IdentifierUtils.longIdentifierFactory();
assertEquals(new Long(0), f.create());
assertEquals(new Long(1), f.create());
assertTrue(f != IdentifierUtils.LONG_IDENTIFIER_FACTORY);
}
public void testLongIncrementingInit() {
Factory f = IdentifierUtils.longIdentifierFactory(true, 100);
assertEquals(new Long(100), f.create());
assertEquals(new Long(101), f.create());
}
public void testLongIncrementingWrap() {
Factory f = IdentifierUtils.longIdentifierFactory(true, Long.MAX_VALUE);
assertEquals(new Long(Long.MAX_VALUE), f.create());
assertEquals(new Long(Long.MIN_VALUE), f.create());
}
public void testLongIncrementingNoWrap() {
Factory f = IdentifierUtils.longIdentifierFactory(false, Long.MAX_VALUE);
try {
f.create();
fail();
} catch (FactoryException ex) {}
}
//--------------------------------------------------------------------------
public void testStringNumericLong() {
Factory f = IdentifierUtils.STRING_NUMERIC_IDENTIFIER_FACTORY;
assertEquals("0", f.create());
assertEquals("1", f.create());
assertEquals("2", f.create());
assertEquals("3", f.create());
assertEquals("4", IdentifierUtils.nextStringNumericIdentifier());
assertEquals("5", f.create());
assertEquals("6", IdentifierUtils.nextStringNumericIdentifier());
assertEquals("7", IdentifierUtils.nextStringNumericIdentifier());
}
public void testStringNumericNoArgs() {
Factory f = IdentifierUtils.stringNumericIdentifierFactory();
assertEquals("0", f.create());
assertEquals("1", f.create());
assertTrue(f != IdentifierUtils.STRING_NUMERIC_IDENTIFIER_FACTORY);
}
public void testStringNumericInit() {
Factory f = IdentifierUtils.stringNumericIdentifierFactory(true, 100);
assertEquals("100", f.create());
assertEquals("101", f.create());
}
public void testStringNumericWrap() {
Factory f = IdentifierUtils.stringNumericIdentifierFactory(true, Long.MAX_VALUE);
assertEquals(Long.toString(Long.MAX_VALUE), f.create());
assertEquals(Long.toString(Long.MIN_VALUE), f.create());
}
public void testStringNumericNoWrap() {
Factory f = IdentifierUtils.stringNumericIdentifierFactory(false, Long.MAX_VALUE);
try {
f.create();
fail();
} catch (FactoryException ex) { }
}
//--------------------------------------------------------------------------
public void testStringAlphanumeric() {
Factory f = IdentifierUtils.STRING_ALPHANUMERIC_IDENTIFIER_FACTORY;
assertEquals("000000000000001", f.create());
assertEquals("000000000000002", f.create());
assertEquals("000000000000003", f.create());
assertEquals("000000000000004", f.create());
assertEquals("000000000000005", f.create());
assertEquals("000000000000006", f.create());
assertEquals("000000000000007", f.create());
assertEquals("000000000000008", f.create());
assertEquals("000000000000009", f.create());
assertEquals("00000000000000a", f.create());
assertEquals("00000000000000b", f.create());
assertEquals("00000000000000c", f.create());
assertEquals("00000000000000d", IdentifierUtils.nextStringAlphanumericIdentifier());
assertEquals("00000000000000e", f.create());
assertEquals("00000000000000f", f.create());
assertEquals("00000000000000g", f.create());
assertEquals("00000000000000h", f.create());
assertEquals("00000000000000i", f.create());
assertEquals("00000000000000j", f.create());
assertEquals("00000000000000k", f.create());
assertEquals("00000000000000l", f.create());
assertEquals("00000000000000m", f.create());
assertEquals("00000000000000n", f.create());
assertEquals("00000000000000o", f.create());
assertEquals("00000000000000p", f.create());
assertEquals("00000000000000q", f.create());
assertEquals("00000000000000r", f.create());
assertEquals("00000000000000s", f.create());
assertEquals("00000000000000t", f.create());
assertEquals("00000000000000u", f.create());
assertEquals("00000000000000v", f.create());
assertEquals("00000000000000w", f.create());
assertEquals("00000000000000x", f.create());
assertEquals("00000000000000y", f.create());
assertEquals("00000000000000z", f.create());
assertEquals("000000000000010", f.create());
assertEquals("000000000000011", f.create());
assertEquals("000000000000012", f.create());
assertEquals("000000000000013", f.create());
}
public void testLongAlphanumericNoArgs() {
Factory f = IdentifierUtils.stringAlphanumericIdentifierFactory();
assertEquals("000000000000001", f.create());
assertEquals("000000000000002", f.create());
assertTrue(f != IdentifierUtils.STRING_ALPHANUMERIC_IDENTIFIER_FACTORY);
}
public void testStringAlphanumericWrap() {
Factory f = IdentifierUtils.stringAlphanumericIdentifierFactory(true, 1);
assertEquals("1", f.create());
assertEquals("2", f.create());
assertEquals("3", f.create());
assertEquals("4", f.create());
assertEquals("5", f.create());
assertEquals("6", f.create());
assertEquals("7", f.create());
assertEquals("8", f.create());
assertEquals("9", f.create());
assertEquals("a", f.create());
assertEquals("b", f.create());
assertEquals("c", f.create());
assertEquals("d", f.create());
assertEquals("e", f.create());
assertEquals("f", f.create());
assertEquals("g", f.create());
assertEquals("h", f.create());
assertEquals("i", f.create());
assertEquals("j", f.create());
assertEquals("k", f.create());
assertEquals("l", f.create());
assertEquals("m", f.create());
assertEquals("n", f.create());
assertEquals("o", f.create());
assertEquals("p", f.create());
assertEquals("q", f.create());
assertEquals("r", f.create());
assertEquals("s", f.create());
assertEquals("t", f.create());
assertEquals("u", f.create());
assertEquals("v", f.create());
assertEquals("w", f.create());
assertEquals("x", f.create());
assertEquals("y", f.create());
assertEquals("z", f.create());
assertEquals("0", f.create());
}
public void testStringAlphanumericNoWrap() {
Factory f = IdentifierUtils.stringAlphanumericIdentifierFactory(false, 1);
assertEquals("1", f.create());
assertEquals("2", f.create());
assertEquals("3", f.create());
assertEquals("4", f.create());
assertEquals("5", f.create());
assertEquals("6", f.create());
assertEquals("7", f.create());
assertEquals("8", f.create());
assertEquals("9", f.create());
assertEquals("a", f.create());
assertEquals("b", f.create());
assertEquals("c", f.create());
assertEquals("d", f.create());
assertEquals("e", f.create());
assertEquals("f", f.create());
assertEquals("g", f.create());
assertEquals("h", f.create());
assertEquals("i", f.create());
assertEquals("j", f.create());
assertEquals("k", f.create());
assertEquals("l", f.create());
assertEquals("m", f.create());
assertEquals("n", f.create());
assertEquals("o", f.create());
assertEquals("p", f.create());
assertEquals("q", f.create());
assertEquals("r", f.create());
assertEquals("s", f.create());
assertEquals("t", f.create());
assertEquals("u", f.create());
assertEquals("v", f.create());
assertEquals("w", f.create());
assertEquals("x", f.create());
assertEquals("y", f.create());
assertEquals("z", f.create());
try {
f.create();
fail();
} catch (FactoryException ex) {}
}
//--------------------------------------------------------------------------
public void testStringSession() {
Factory f = IdentifierUtils.STRING_SESSION_IDENTIFIER_FACTORY;
assertTrue(f != IdentifierUtils.stringSessionIdentifierFactory());
String a = (String) f.create();
String b = (String) IdentifierUtils.nextStringSessionIdentifier();
assertTrue(a.length() >= 10);
assertTrue(b.length() >= 10);
// could fail, but unlikely
assertTrue(a.substring(6, 9) != b.substring(6, 9));
assertEquals("0", a.substring(9));
assertEquals("1", b.substring(9));
}
//--------------------------------------------------------------------------
}
1.1 jakarta-commons/lang/src/java/org/apache/commons/lang/util/IdentifierUtils.java
Index: IdentifierUtils.java
===================================================================
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.commons.lang.util;
import java.io.Serializable;
import java.util.Random;
import org.apache.commons.lang.functor.Factory;
import org.apache.commons.lang.functor.FactoryException;
/**
* <p><code>IdentifierUtils</code> provides a number of different identifier
* reference implementations.</p>
*
* <p>All the identifer factories are serializable and synchronized. The
* factories all implement the <i>functor</i>
* {@link org.apache.commons.lang.functor.Factory Factory} interface</p>
*
* @author Stephen Colebourne
* @version $Id: IdentifierUtils.java,v 1.1 2002/12/29 21:35:04 scolebourne Exp $
*/
public class IdentifierUtils {
/**
* <p>Singleton instance of the
* <code>LongIdentifierFactory</code>.</p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated.</p>
*
* <p>The objects returned are:</p>
* <ul>
* <li>new Long(0L)
* <li>new Long(1L)
* <li>new Long(2L)
* <li>...
* </ul>
*/
public static final Factory LONG_IDENTIFIER_FACTORY = new LongIdentifierFactory(true, 0L);
/**
* <p>Singleton instance of the <code>StringNumericIdentifierFactory</code>.
* </p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated.</p>
*
* <p>The objects returned are:</p>
* <ul>
* <li>"0"
* <li>"1"
* <li>"2"
* <li>...
* </ul>
*/
public static final Factory STRING_NUMERIC_IDENTIFIER_FACTORY = new StringNumericIdentifierFactory(true, 0L);
/**
* <p>Singleton instance of the
* <code>StringAlphanumericIdentifierFactory</code>.</p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated. However, the length is 15 in base-36, so thats a
* lot of identifiers.</p>
*
* <p>The objects returned are:</p>
* <ul>
* <li>"000000000000001"
* <li>"000000000000002"
* <li>"000000000000003"
* <li>...
* <li>"00000000000000y"
* <li>"00000000000000z"
* <li>"000000000000010"
* <li>"000000000000011"
* <li>...
* <li>"00000000000001z"
* <li>"000000000000020"
* <li>...
* </ul>
*/
public static final Factory STRING_ALPHANUMERIC_IDENTIFIER_FACTORY = new StringAlphanumericIdentifierFactory(true, 15);
/**
* <p>Singleton instance of the
* <code>StringSessionIdentifierFactory</code>.</p>
*
* <p>The singleton instance may produce duplicates in a long-lived server,
* but its unlikely.</p>
*
* <p>The objects returned are 10 or more base-36 digits.</p>
*/
public static final Factory STRING_SESSION_IDENTIFIER_FACTORY = new StringSessionIdentifierFactory();
//---------------------------------------------------------------------------------
/**
* <p><code>IdentifierUtils</code> instances should NOT be constructed in
* standard programming.</p>
*
* <p>This constructor is public to permit tools that require a JavaBean instance
* to operate.</p>
*/
public IdentifierUtils() {
super();
}
//---------------------------------------------------------------------------------
/**
* <p>Gets the next identifier using the singleton instance of the
* Long factory.
* </p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated.</p>
*
* @return a new identifier
*/
public static Long nextLongIdentifier() {
return (Long) LONG_IDENTIFIER_FACTORY.create();
}
/**
* <p>Gets a new identifier factory that returns a series of Long objects
* increasing in size.</p>
*
* <p>The factory will wrap when the maximum <code>long</code> is
* reached and return negative numbers. It will start from zero.</p>
*
* @return a new identifier factory
*/
public static Factory longIdentifierFactory() {
return new LongIdentifierFactory(true, 0L);
}
/**
* <p>Gets a new identifier factory that returns a series of Long objects
* increasing in size.</p>
*
* @param wrap should the factory wrap when it reaches the maximum
* long value (or throw an exception)
* @param initialValue the initial long value to start at
* @return a new identifier factory
*/
public static Factory longIdentifierFactory(boolean wrap, long initialValue) {
return new LongIdentifierFactory(wrap, initialValue);
}
//---------------------------------------------------------------------------------
/**
* <p>Gets the next identifier using the singleton instance of the
* String Numeric factory.
* </p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated.</p>
*
* @return a new identifier
*/
public static String nextStringNumericIdentifier() {
return (String) STRING_NUMERIC_IDENTIFIER_FACTORY.create();
}
/**
* <p>Gets a new identifier factory that returns a series of String objects
* representing numbers increasing in size.</p>
*
* <p>The factory will wrap when the maximum <code>long</code> is
* reached and return negative numbers. It will start from zero.</p>
*
* @return a new identifier factory
*/
public static Factory stringNumericIdentifierFactory() {
return new StringNumericIdentifierFactory(true, 0L);
}
/**
* <p>Gets a new identifier factory that returns a series of String objects
* representing numbers increasing in size.</p>
*
* @param wrap should the factory wrap when it reaches the maximum
* long value (or throw an exception)
* @param initialValue the initial long value to start at
* @return a new identifier factory
*/
public static Factory stringNumericIdentifierFactory(boolean wrap, long initialValue) {
return new StringNumericIdentifierFactory(wrap, initialValue);
}
//---------------------------------------------------------------------------------
/**
* <p>Gets the next identifier using the singleton instance of the
* String Alphanumeric factory.
* </p>
*
* <p>The singleton instance will wrap, so in a long-lived server, the id
* may be duplicated.</p>
*
* @return a new identifier
*/
public static String nextStringAlphanumericIdentifier() {
return (String) STRING_ALPHANUMERIC_IDENTIFIER_FACTORY.create();
}
/**
* <p>Gets a new identifier factory that returns a series of String objects
* representing numbers increasing in size in base-36.</p>
*
* <p>The factory will wrap when the maximum size (15) is reached.</p>
*
* @return a new identifier factory
*/
public static Factory stringAlphanumericIdentifierFactory() {
return new StringAlphanumericIdentifierFactory(true, 15);
}
/**
* <p>Gets a new identifier factory that returns a series of String objects
* representing numbers increasing in size in base-36.</p>
*
* @param wrap should the factory wrap when it reaches the maximum
* size (or throw an exception)
* @param size the number of characters the id should fill
* @return a new identifier factory
*/
public static Factory stringAlphanumericIdentifierFactory(boolean wrap, int size) {
return new StringAlphanumericIdentifierFactory(wrap, size);
}
//---------------------------------------------------------------------------------
/**
* <p>Gets the next identifier using the singleton instance of the
* String Session factory.
* </p>
*
* <p>The singleton instance is not guaranteed to be unique (although its
* pretty unlikely), so in a long- lived server, the id may be duplicated.
* </p>
*
* @return a new identifier
*/
public static String nextStringSessionIdentifier() {
return (String) STRING_SESSION_IDENTIFIER_FACTORY.create();
}
/**
* <p>Gets a new identifier factory that returns a series of String objects
* that appear to be random and are suitable for use as session identifiers.
* </p>
*
* <p>The generation routine is based on a random number and a counter
* within a 2 second time interval.</p>
*
* @return a new identifier factory
*/
public static Factory stringSessionIdentifierFactory() {
return new StringSessionIdentifierFactory();
}
//---------------------------------------------------------------------------------
/**
* <code>LongIdentifierFactory</code> is an Identifier Factory
* that generates an incrementing number as a Long object.
*
* @author Stephen Colebourne
*/
private static class LongIdentifierFactory implements Factory, Serializable {
/** Should the counter wrap. */
private final boolean wrap;
/** The counter. */
private long count = 0;
/**
* Constructor.
*
* @param wrap should the factory wrap when it reaches the maximum
* long value (or throw an exception)
* @param initialValue the initial long value to start at
*/
private LongIdentifierFactory(boolean wrap, long initialValue) {
super();
this.wrap = wrap;
this.count = initialValue;
}
/**
* Create a new identifier.
*
* @return a new identifier as a Long
*/
public Object create() {
long value = 0;
if (wrap) {
synchronized (this) {
value = count++;
}
} else {
synchronized (this) {
if (count == Long.MAX_VALUE) {
throw new FactoryException("The maximum number of identifiers has been reached");
}
value = count++;
}
}
return new Long(value);
}
}
//---------------------------------------------------------------------------------
/**
* <code>StringNumericIdentifierFactory</code> is an Identifier Factory
* that generates an incrementing number as a String object.
*
* @author Stephen Colebourne
*/
private static class StringNumericIdentifierFactory implements Factory, Serializable {
/** Should the counter wrap. */
private final boolean wrap;
/** The counter. */
private long count = 0;
/**
* Constructor.
*
* @param wrap should the factory wrap when it reaches the maximum
* long value (or throw an exception)
* @param initialValue the initial long value to start at
*/
private StringNumericIdentifierFactory(boolean wrap, long initialValue) {
super();
this.wrap = wrap;
this.count = initialValue;
}
/**
* Create a new identifier.
*
* @return a new identifier as a String
*/
public Object create() {
long value = 0;
if (wrap) {
synchronized (this) {
value = count++;
}
} else {
synchronized (this) {
if (count == Long.MAX_VALUE) {
throw new FactoryException("The maximum number of identifiers has been reached");
}
value = count++;
}
}
return Long.toString(value);
}
}
//---------------------------------------------------------------------------------
/**
* <code>StringAlphanumericIdentifierFactory</code> is an Identifier Factory
* that generates an incrementing incrementing number in base 36 as a String
* object.
*
* @author Stephen Colebourne
*/
private static class StringAlphanumericIdentifierFactory implements Factory, Serializable {
/** Should the counter wrap. */
private final boolean wrap;
/** The counter. */
private char[] count = null;
/**
* Constructor.
*
* @param wrap should the factory wrap when it reaches the maximum
* long value (or throw an exception)
* @param size the size of the identifier
*/
private StringAlphanumericIdentifierFactory(boolean wrap, int size) {
super();
this.wrap = wrap;
if (size < 1) {
throw new IllegalArgumentException("The size must be at least one");
}
this.count = new char[size];
for (int i = 0; i < size; i++) {
count[i] = '0'; // zero
}
}
/**
* Create a new identifier.
*
* @return a new identifier as a String
*/
public synchronized Object create() {
for (int i = count.length - 1; i >= 0; i--) {
switch (count[i]) {
case 122: // z
count[i] = '0';
if (i == 0 && wrap == false) {
throw new FactoryException("The maximum number of identifiers has been reached");
}
break;
case 57: // 9
count[i] = 'a';
i = -1;
break;
default:
count[i]++;
i = -1;
break;
}
}
return new String(count);
}
}
//---------------------------------------------------------------------------------
/**
* <p><code>StringSessionIdentifierFactory</code> is an Identifier
* Factory that generates an alphanumeric 10+ character identifier. The
* exact length depends on the number of ids requested per time period.</p>
*
* <p>Originally designed for JServ sessions. Uses synchronized count and
* time to ensure uniqueness. Not guaranteed unique across JVMs, but
* fairly safe none the less.</p>
*
* @author Jon S. Stevens
* @author Neeme Praks
* @author Stephen Colebourne
*/
private static class StringSessionIdentifierFactory implements Factory, Serializable {
/**
* We want to have a random string with a length of 6 characters.
* Since we encode it base-36, we modulo the random number with
* this value.
*/
private static final long MAX_RANDOM_LEN = 2176782336L; // 36 ** 6
/**
* The identifier must be unique within the typical lifespan of a
* session; the value can roll over after that. 3 characters:
* (this means a roll over after over a day, which is much larger
* than a typical lifespan).
*/
private static final long MAX_TIME_SECTION_LEN = 46656L; // 36 ** 3
/**
* Milliseconds between different tics. The 3-character time
* string has a new value every 2 seconds.
*/
private static final long TIC_DIFFERENCE = 2000;
/** The incrementing counter. */
private int counter = 0;
/** The last time. */
private long lastTimeValue = 0;
/** The randmonizer. */
private Random randomizer = new Random();
/**
* Constructor.
*/
private StringSessionIdentifierFactory() {
super();
}
/**
* Create a new identifier. Only guaranteed unique within
* this JVM, but fairly safe for cross JVM usage as well.
*
* <p>Format of identifier is
* [6 chars random][3 chars time][1+ chars count]</p>
*
* @return a new identifier as a Long
*/
public Object create() {
// Random value
//--------------
long currentRandom = randomizer.nextLong();
if (currentRandom < 0) {
currentRandom = -currentRandom;
}
// force value into 6 char range, and add to pad with zeros
// this gives a length of 7, when converted to base 36, and
// the first character (always 1 from the add) is dropped
currentRandom %= MAX_RANDOM_LEN;
currentRandom += MAX_RANDOM_LEN;
long currentTimeValue = 0;
int currentCount = 0;
synchronized (this) {
// Time
//--------------
currentTimeValue = (System.currentTimeMillis() / TIC_DIFFERENCE);
// force value into 3 char range, and add to pad with zeros
// this gives a length of 4, when converted to base 36, and
// the first character (always 1 from the add) is dropped
currentTimeValue %= MAX_TIME_SECTION_LEN;
currentTimeValue += MAX_TIME_SECTION_LEN;
// Count
//--------------
// Make the string unique by appending the count since last
// time flip.
// Count sessions only within tics (so the 'real' counter
// isn't exposed to the public).
if (lastTimeValue != currentTimeValue) {
lastTimeValue = currentTimeValue;
counter = 0;
}
currentCount = counter++;
}
// build string
//--------------
StringBuffer id = new StringBuffer(15);
id.append(Long.toString(currentRandom, 36).substring(1)); // 6 chars
id.append(Long.toString(currentTimeValue, 36).substring(1)); // 3 chars
id.append(Long.toString(currentCount, 36)); // 1+ chars
return id.toString();
}
}
}
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