Overriding default implementation of TrustManager class

The IBM JSSE provider's default TrustManager implementation doesn't allow anonymous cipher suites.
http://www-128.ibm.com/developerworks/library/j-ibmsecurity.html?ca=drs-j4304
I want to override it, so that anonymous cipher suites can be allowed.
Does anyone know how to do this.
Thanks,
JVR

A custom renderer needs to extend the abstract class
javax.faces.Renderer and supply five methods. Four of
them (encodeXXX and decode) make perfect sense, but
the fifth one (getClientId) isn't in the same league.
Wouldn't most renderers want to use the standard
mechanism?
Thanks for the feedback.
This issue is already on the Expert Group's radar as an issue to be addressed. I would not be at all surprised if we end up with a standard base class for Renderers that includes a default implementation for things like getClientId().
Craig

Similar Messages

Overriding default constructor in extended class

I've got some code that extends UnicastRemoteObject. The UnicastRemoteObject's default constructor open a random tcp/ip port. I'd like to control what port is opened. The UnicastRemoteObject has another constructor which takes a port as input. I'd like to override the default constructor. I've read that if I specify a call to super(<int>) that the default constructor wouldn't be called but the constructor taking an int would be called. I tried this but got both the default constructor (random tcp/ip port opened) and the constructor I called (shown by the port I specified being opened). Am I doing something wrong? Is there another way to control the constructor initiated in the class that is extended ?

I'd like to
override the default constructor.Yes but why?
I've read that if I
specify a call to super(<int>) that the default
constructor wouldn't be called but the constructor
taking an int would be called.Correct.
I tried this but got
both the default constructor (random tcp/ip port
opened) and the constructor I called (shown by the
port I specified being opened).I doubt this very much. You need to review your evidence for this assertion. You should call super(port) if you have a specific port in mind, and in JDK 1.5 you should call it anyway with 0 if you don't want to have to generate stubs.
This question would be better off in the RMI forum.
EJP

Default implementations of JPDK V2 classes and interfaces - is the source code?

Hi
Is the source code for all the default implementations of the JPDK interfaces, renderers etc. available somewhere?
Regards
Harry

Please find jpdk samples sources for jpdk implementation under src.zip inside PDK.zip
In addition, one can many articles related to PDK under articles folder.

How to implement a java class in javafx?

public interface WarningEvent {
    public void warningHandler ();
function test ():Void {
        var warningEvent:WarningEvent = new WarningEvent() {
            public void warnHandler(){
    }I am trying to implement java method inside javafx, but without luck. I also tried override with javafx syntax, but still cannot get it. Any one could help on this?
Thanks.

1) Get rid of the keyword new
2) Get rid of braces ()
3) For the function declaration, use the JavaFX syntax, not the Java syntax!
function test ():Void {
        var warningEvent:WarningEvent = WarningEvent {
            override public warnHandler():Void {
}Your class need to have a default constructor (the one without any argument) to be able to do this (and in this case it works because you have an interface instead).

Override default printing behaviour

Hi all,
I would like overriding the default printing delivery behaviour. What should I do in order to archive this? should I implement a java class? if yes, which class has have to be inherit from? and how to register the class such that this class is being called?
Thx
Reards,
whching

Try posting at the Web Development / Standards Evangelism forum at MozillaZine. The helpers over there are more knowledgeable about web page development issues with Firefox. <br />
http://forums.mozillazine.org/viewforum.php?f=25 <br />
You'll need to register and login to be able to post in that forum.

Configuring Kodo default implementation for field of Collection type

If I am not mistaken default implementation for field of Collection type in
Kodo is
LinkedList based proxy. It would be great if it were possible to configure
Kodo to use a proxy of my choosing
I did some tests and it seems to me that ArrayList is much more efficient
than Linked list (see below)
Is there any specific reason I am not aware of that makes LinkedList better
than array list
In my applications all collections a relatively small (or at least most of
my collections are definitely small)
and since I use Collection interface there is no inserts into middle of my
collections - only appends (which ArrayList handles very well)
So my question is can I make Kodo to use ArrayListProxy for fields of
Collection type
(except of course using ArrayList field instead of Collection which I do not
want to do)
below is some statistics on collection performance (populating and iterating
collections)
the same test against 3 collections implementations (JDK 1.4.1)
Not only ArrayList by far the fastest and memory friendly it also garbage
collected much sooner and better -
I show here max memory consumption and last to would not be garbage
collected till all memory is in use (old generation GC)
and ArrayList seems to be collected by young gen GC because it was collected
very quickly between test cycles why other only when all memory was used
So please make ArrayList your default collection implementation :-)
Small collection size (40)
time(ms) memory(kb)
ArrayList 5,218 62,154
LinkedList 14,125 240,066
HashSet 27,000 311,825
the same but using using random inserts - append(index, object) rather than
append(object):
ArrayList 8937, 53591
LinkedList 15047, 240066
Larger collection size (200)
ArrayList 4860, 47709
LinkedList 18468, 290704
HashSet 34391, 422282
the same but using using random inserts - append(index, object) rather than
append(object):
ArrayList 11844, 47709
LinkedList 25766, 290704

You should be able to accomplish this fairly easily by extending
SimpleProxyManager:
http://solarmetric.com/Software/Documentation/2.4.3/docs/javadoc/com/solarmetric/kodo/util/SimpleProxyManager.html
and overriding the appropriate methods (getCollectionCopy and
getCollectionProxy).
On Mon, 12 May 2003 12:26:21 -0400, Alex Roytman wrote:
If I am not mistaken default implementation for field of Collection type in
Kodo is
LinkedList based proxy. It would be great if it were possible to configure
Kodo to use a proxy of my choosing
I did some tests and it seems to me that ArrayList is much more efficient
than Linked list (see below)
Is there any specific reason I am not aware of that makes LinkedList better
than array list
In my applications all collections a relatively small (or at least most of
my collections are definitely small)
and since I use Collection interface there is no inserts into middle of my
collections - only appends (which ArrayList handles very well)
So my question is can I make Kodo to use ArrayListProxy for fields of
Collection type
(except of course using ArrayList field instead of Collection which I do not
want to do)
below is some statistics on collection performance (populating and iterating
collections)
the same test against 3 collections implementations (JDK 1.4.1)
Not only ArrayList by far the fastest and memory friendly it also garbage
collected much sooner and better -
I show here max memory consumption and last to would not be garbage
collected till all memory is in use (old generation GC)
and ArrayList seems to be collected by young gen GC because it was collected
very quickly between test cycles why other only when all memory was used
So please make ArrayList your default collection implementation :-)
Small collection size (40)
time(ms) memory(kb)
ArrayList 5,218 62,154
LinkedList 14,125 240,066
HashSet 27,000 311,825
the same but using using random inserts - append(index, object) rather than
append(object):
ArrayList 8937, 53591
LinkedList 15047, 240066
Larger collection size (200)
ArrayList 4860, 47709
LinkedList 18468, 290704
HashSet 34391, 422282
the same but using using random inserts - append(index, object) rather than
append(object):
ArrayList 11844, 47709
LinkedList 25766, 290704

Why does the child class need to implement the parent classes constructor?/

As I was playing around with some code I came across this point :
First Class
public class A {
     public int x;
     A(int i){
          x=i;
          System.out.println("A is initialised");
}Second Class extending it :
public class B extends A{
     private int y;
   // Why do I need this constructor to call parents constructor?
// My guess is so that when i make an object of class B referring to class A it should make sense?
     B(int i) {
          super(i);
          y=test;
public static void main(String args[]){
      A a = new A(1);
      A b = new B(1); make an object of class B referring to class A it should work!!
      B c = new B(2);
      B d =(B) new A(2); --> gives class cast exception!
}I am little confused here, Can someone throw more light on it.
Thanks

You don't override constructors. However, every class, in it's constructor, must call some constructor from the class it's extending. In most cases this is simply super(). However, if your class does not have a default constructor (i.e. you've declared any other constructor, or the sub class does not have access to it, I.E. you've declared it private) then you must include a call to some other constructor in the super class. The constructor in the subclass does not have to be the same as the super class one, but you do have to invoke a constructor from the super class. I.E.
class A {
A(int i) {}
class B extends A {
B(String b) {
    super(0);
}

Default implementation of mouse drag event?

Is there any Default implementation of mouse drag event?
Say if the developer does not override and implement mouse drag event, still when the frame is dragged, the frame gets repainted itself in the new position. It indicates some default implementation of mouse drag event, but am unable to find out where it has been implemented.
Why bother when everything works fine? I have a requirement to move my non-modal dialog when the frame is being dragged to another location. I tried adding mousemotionlistener to the frame, to the panel inside a frame, but the event does not reach my custom implementation of mousedrag event.
Any clues?

Moving the frame is a different listener: ComponentListener; add one to the frame. The frame's window decorations are OS territory, so I'm not sure if there's system dependence. I seem to vaguely remember some systems sending an event only after done moving, while others send the event as the frame moves.

How to implement a java class in my form .

Hi All ,
I'm trying to create a Button or a Bean Area Item and Implement a class to it on the ( IMPLEMENTATION CLASS ) property such as ( oracle.forms.demos.RoundedButton ) class . but it doesn't work ... please tell me how to implement such a class to my button .
Thanx a lot for your help.
AIN
null

hi [email protected]
tell me my friend .. how can i extend
the standard Forms button in Java ? ... what is the tool for that ... can you explain more please .. or can you give me a full example ... i don't have any expereience on that .. i'm waiting for your reply .
Thanx a lot for your cooperation .
Ali
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by [email protected]:
Henrik, the Java importer lets you call Java classes on the app server side - I think what Ali is trying to do is integrate on the client side.
If you want to add your own button then if you extend the standard Forms button in Java and then use this class name in the implementation class property then the Java for your button will be used instead of the standard Forms button. And since it has extended the basic Forms button it has all the standard button functionality.
There is a white paper on OTN about this and we have created a new white paper which will be out in a couple of months (I think).
Regards
Grant Ronald<HR></BLOCKQUOTE>
null

How to implement a singleton class across apps in a managed server}

Hi ,
I tried implementing a singleton class , and then invoking the same in a filter class.
Both are then deployed as a web app (war file) in a managed server.
I created a similar app , deployed the same as another app in the same managed server .
I have a logger running which logs the singleton instances as well.
But am getting two instances of the singleton class in the two apps - not the same .
I was under the impression that , a singleton is loaded in the class loader level , and since all apps under the same managed server used the same JVM , singleton will only get initialized once.
Am i missing something here ? or did i implement it wrong..?
public class Test
   private static Test ref ;
   private DataSource X;
   static int Y;
   long Z ;
   private Test ()
      // Singleton
       Z= 100 ;
   public static synchronized Test getinstance() throws NamingException, SQLException
      if(ref == null)
         ref = new Test() ;
         InitialContext ic = new InitialContext();
         ref.X = (DataSource)ic.lookup ("jdbc/Views");
      return ref ;
   public Object clone()throws CloneNotSupportedException
       throw new CloneNotSupportedException();
   public int sampleMethod (int X) throws SQLException
public final class Filter implements Filter
     public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException
          try
               Test ref = Test.getinstance();
               log.logNow(ref.toString());
}Edited by: Tom on Dec 8, 2010 2:45 PM
Edited by: Tom on Dec 8, 2010 2:46 PM

Tom wrote:
Hi ,
I tried implementing a singleton class , and then invoking the same in a filter class.
Both are then deployed as a web app (war file) in a managed server.
I created a similar app , deployed the same as another app in the same managed server .
I have a logger running which logs the singleton instances as well.
But am getting two instances of the singleton class in the two apps - not the same .Two apps = two instances.
Basically by definition.
>
I was under the impression that , a singleton is loaded in the class loader level , and since all apps under the same managed server used the same JVM , singleton will only get initialized once. A class is loaded by a class loader.
Any class loader that loads a class, by definition loads the class.
A VM can have many class loaders. And far as I know every JEE server in existance that anyone uses, uses class loaders.
And finally there might be a problem with the architecture/design of a JEE system which has two applications but which is trying to solve it with a singleton. That suggests a there might be concept problem with understanding what an "app" is in the first place.

Implementing a secure class loader..

Hello,
We have a custom class loader which loads in custom packages from the database or from the file system. We want to ensure that these custom classes do not read or write into the file system. I want to restrict access to these classes when creating them. I read that by setting the proper permissions when defining the class, this could be possible. Here is my implementation of the class loader :
import java.io.File;
import java.io.FileInputStream;
import java.io.FilePermission;
import java.io.IOException;
import java.net.SocketPermission;
import java.net.URL;
import java.security.AccessController;
import java.security.CodeSource;
import java.security.PermissionCollection;
import java.security.Permissions;
import java.security.PrivilegedExceptionAction;
import java.security.SecureClassLoader;
public class TestClassLoader extends SecureClassLoader {
        JarParser jp;
        public TestClassLoader(JarParser jp) {
          super();
                this.jp = jp;
        public Class findClass(final String name) throws ClassNotFoundException {
               try {
                   return(Class)
                           AccessController.doPrivileged (
                                 new PrivilegedExceptionAction() {
                                               public Object run() throws ClassNotFoundException {
                                                     byte[] buf = null;
                                                        try {
                                                           if(jp == null)
                                                                  throw new ClassNotFoundException("Jar file not found");
                                                                String className = name.replace( '.', '/' ) + ".class";
                                                                buf = jp.getResource(className);
                                                                if(buf == null || buf.length == 0)
                                                                      throw new ClassNotFoundException("Class not found");
                                                                CodeSource cs = getCodeSource(name);
                                                                return defineClass(name, buf, 0, buf.length, cs);
                                                       catch(Exception e) {
                                                            throw new ClassNotFoundException(name, e);
               catch(Exception e) {
                    throw new ClassNotFoundException(name, e);
      * @param name
     protected CodeSource getCodeSource(String name) {
               try {
                   return new CodeSource(new URL("file", "localhost", name), null);
               catch(Exception e){
                     e.printStackTrace();
                return null;
        protected PermissionCollection getPermissions(CodeSource cs) {
          PermissionCollection pc = new Permissions();
                pc.add(new RuntimePermission("exitVM"));
                pc.add(new FilePermission("${user.home}${/}*", "read"));
                pc.add(new FilePermission("${user.dir}${/}*", "read"));
         pc.add(new SocketPermission("localhost", "resolve"));
                return pc;
        public static void main(String[] args) {
                try {
                   byte[] bytes = new byte[8192];
                  long ttlBytesRead = 0;
                  int noOfBytesToRead = 0;
                        File readFile = new File("test.jar");
                        // "length" here indicates the total no of bytes to read.
                      // This is equal to the file size sans the offset value.
                        long length = readFile.length();
                        Long temp;
                      FileInputStream readFis = null;
                        // Create the RandomAccessFile
                  try{
                             readFis = new FileInputStream(readFile);
                       catch(Exception e) {
                            throw new IOException(e.getMessage());
                       long tempLong;
                  StringBuffer buffer = new StringBuffer();
                        do {
                            if ((length - ttlBytesRead) > 8192)
                                     tempLong = 8192;
                                else
                                    tempLong = (length - ttlBytesRead);
                             temp = new Long((length - ttlBytesRead) > 8192 ? 8192 : (length - ttlBytesRead));
                               noOfBytesToRead = temp.intValue();
                              if(noOfBytesToRead == 0)
                                        break;
                          // Read the specified no of bytes into the byte
                                // array from the file.
                         try {
                                   readFis.read(bytes,0,noOfBytesToRead);
                               catch(Exception e1) {
                                   throw new IOException(e1.getMessage());
                               String str = new String(bytes, 0, noOfBytesToRead);
                            buffer.append(str);
                                ttlBytesRead += noOfBytesToRead;
                        } while(ttlBytesRead < length);
                 try {
                           readFis.close();
                       catch(Exception e1) {}
                        JarParser jp = new JarParser("test.jar", buffer.toString().getBytes());
                 TestClassLoader tcl = new TestClassLoader(jp);
                  Class class1 = tcl.findClass("com.test.TestFileWrite");
                 Object obj = class1.newInstance();
               catch(Exception e) {
                    e.printStackTrace();
}JarParser is the class which parses through the jar file and caches the contents as bytes.
The test.jar contains a single class which writes into the user's home directory. As you can see, I have granted only read access on the home dir.
When I run this however, the newly loaded class does manage to write into the file system with no problems. Is there anything further that I need to do to enable restriction on the file system ?
Thanks.

If I've been reading correctly, they don't want you
subclassing SecurityManager for security any more.
Everything should be handled by the AccessController
using Permission objects. The easiest way to configure
the AccessController is through policy files.erg. where did you read this? I checked the 1.5.0 beta API just now, and nothing is officially deprecated.
:{ I don't have time to figure out the AccessController API right now.
I have yet to find a good tutorial on the matter of
security and classloaders. If anyone has a good
reference, it would be much appreciated.I second that.
And as a temporary solution (because we're already behind schedule), I went ahead and wrote my own SecurityManager, using the ideas I mentioned above.
I'm posting it at the site below in case anyone can offer any feedback (such as pointing out fatal weaknesses). We tried yesterday for an hour or so to break it, and it withstood all our tests; but security is not our specialty, so there's probably room for improvement.
(I'd post it in this message, but it's a wee bit large.)
www.personal.utulsa.edu/~jeremy-wood/software/ThreadBasedSecurityManager.java
(And if it passes your scrutiny and looks useful, feel free to use it. But note the disclaimers.)

Default Implementation for PersistenceProvider

I am going to test my persistence layer outside of Java EE server.
Using jboss embedded ejb server, I write a persistence.xml with the following:
<provider>
org.hibernate.ejb.HibernatePersistence
</provider>
<transaction-type>RESOURCE_LOCAL<transaction-type>
Is there any default ORM in jboss server or reference implementation, so I can remove hibernate from my test environment?
i.e. is there any default implementation for PersistenceProvider.

I am going to test my persistence layer outside of Java EE server.
Using jboss embedded ejb server, I write a persistence.xml with the following:
<provider>
org.hibernate.ejb.HibernatePersistence
</provider>
<transaction-type>RESOURCE_LOCAL<transaction-type>
Is there any default ORM in jboss server or reference implementation, so I can remove hibernate from my test environment?
i.e. is there any default implementation for PersistenceProvider.

Problem overriding default JSF conversion error messages

Hello !
I have a problem to override default JSF conversation error message. I have an inputText which is binded to BigDecimal attribute, so when I enter a character in that field I get this error message: "- Conversion failed."
I think I need to register the message bundle in my faces config, and put the key of this error message to my properties file.. am I right ?
Can somebody help me with this ? Which key I need to put into the properties file ?
Miljan

Get [Sun's Java EE tutorial |https://www.sun.com/offers/details/JavaEETutorial.xml?cid=20090723ZA_TACO_JVEE_0004] and read the relevant section so you don't have to guess what you need to do.

Need the default configuration of map-class and policies for WAAS version 5.3.1.20

Do someone have the default configuraion cli of class-maps and policies for the WAAS version 5.3.1.20. I need this to compare with the configuration that I have in the network, I need the verify what have been changed.

I'm sure you figured this out already since it's been 9 months. But just in case someone needs this - you can restore the default policies if they don't show up. Device Groups -> AllWAASGroup and edit. There you will see a "Restore default Optimization Policies"

Instance of one of implementations of abstract class depending on context??

Hi all,
I just wonder if it is possible in Java to call creation of a new instance of an implementation of an abstract class depending on context.
I mean something like:
abstract class Abstract
//1st implementation of Abstract class
class Concrete1 extends Abstract
//2nd implementation of Abstract class
class Concrete2 extends Abstract
}And now, somewhere else in the code, I would really need to call something like this:
Abstract test1 = new ...(); //here I need sometimes to be created instance of Concrete1, sometimes instance of Concrete2
Is there a way how to do this??

Some more concrete code if it helps:
Abstract class:
* Individual.java
* Created on 21. leden 2007, 1:08
package genetics;
* Abstract class defining fields and methods of one individual for genetic algorithms
* This class is supposed to be implemented according to problem to be solved
* @author Richard V�tek
* @version 1.0
abstract public class Individual implements Comparable<Individual>
   * Create random chromosomes for this individual
protected abstract void createRandomChromosomes();
   * Count fitness of this individual
   * This number says how good is this individual (the higher number the better).
   * Better fitness means that this individual is closer to solution.
   * @return int   Fitness of this individual
protected abstract int getFitness();
   * Cross-breed this individual with another individual
   * This leaves untouched number of chromosomes to certain (randomly generated) position.
   * From this position on, it will swap chromosomes between this and another individual.
   * So this individual gets changed (cross-breeded) as well as the other, which is returned
   * as result of this method.
   * @param   other              The other individual to cross-breed with
   * @return Individual         Hybrid of this and another individual (in fact, the other individual
   *                             after cross-breed (this (source) individual gets changed too after cross-breed)
protected abstract Individual crossbreed(Individual other);
   * Mutate this individual
   * Mutate chromosomes of this individual; every chromosome is mutated
   * with probability set in settings of evolution.
   * This probability is supposed to be quite low number, roughly 1 %.
protected abstract void mutate();
   * Check this individual
   * Check if this individual still suits the assignment.
   * If not, repair this individual to suit it again.
protected abstract void check();
   * Implementation of Comparable: comparing of individuals by fitness
   * @param other Another individual to compare
public int compareTo(Individual other)
    return this.getFitness() - other.getFitness();
One implementation class:
* KnapsackIndividual.java
* Created on 21. leden 2007, 1:41
package genetics;
import java.util.Random;
import java.util.TreeMap;
import knapsack.KnapsackProblem;
* This is practically the same as KnapsackProblem class but designed specially
* for solving knapsack problem with genetic algorithm so all unnecessary fields
* and methods are removed.
* @author Richard V�tek
* @version 1.0
public class KnapsackIndividual extends Individual
   * Chromosomes of this individual
   * In case of knapsack problem, they are things currentl in knasack
protected boolean[] arrChromosomes;
   * Cached value of fitness of this individual
   * Used to not to count fitness of this individual everytime when needed
   * (and it is often needed); once counted, it will be read from this cached value
private int intFitnessCache = Integer.MIN_VALUE;
   * Randomizer for random-driven methods (like mutation, etc.)
private Random randomizer = new Random();
   * Reference to evolution to read mutation probability from
protected Evolution evolution;
   * Assignment of problem instance
protected KnapsackProblem assignment;
   * Create a new Individual instance
   * @param   assignment Object representing assignment of particular problem
   * @param   evolution   Reference to evolution object to be able to read evolution's settings from
public KnapsackIndividual(KnapsackProblem assignment, Evolution evolution)
    this.assignment = assignment;
    this.evolution = evolution;
    this.arrChromosomes = new boolean[assignment.getNumberOfThings()];
   * Create random chromosomes for this individual
   * @see Individual#createRandomChromosomes()
protected void createRandomChromosomes()
    int intChromosomeCount = this.arrChromosomes.length;
    for (int i = 0; i < intChromosomeCount; i++)
      this.arrChromosomes[i] = this.randomizer.nextBoolean();
   * Get fitness of this individual
   * In case of knapsack, fitness is sum of prices of all things currently in knapsack
   * @see Individual#getFitness()
protected int getFitness()
    //if cached value exist, return it
    if (this.intFitnessCache != Integer.MIN_VALUE)
      return this.intFitnessCache;
    //otherwise, count fitness of this individual
    int intChromosomeCount = this.arrChromosomes.length;
    int intSumOfValues = 0;
    //in case of knapsack, fitness is value of all things currently in knapsack
    //(sum of values of all things in knapsack)
    for (int i = 0; i < intChromosomeCount; i++)
      intSumOfValues = this.assignment.arrPrices;
//save counted fitness to cache
this.intFitnessCache = intSumOfValues;
return intSumOfValues;
* Cross-breed two individuals
* @param other The other individual for cross-breed
* @return The other individual after cross-breed (but this individual is affected too)
* @see Individual#crossbreed()
protected Individual crossbreed(Individual other)
int intChromosomeCount = this.arrChromosomes.length;
//position from which on swap chromosomes of this and the other individual
int intCrossbreedPosition = this.randomizer.nextInt(intChromosomeCount);
boolean booTemp;
//swap chromosomes from cross-breed position on
for (int i = intCrossbreedPosition; i < intChromosomeCount; i++)
booTemp = ((KnapsackIndividual) this).arrChromosomes[i];
((KnapsackIndividual) this).arrChromosomes[i] = ((KnapsackIndividual) other).arrChromosomes[i];
((KnapsackIndividual) other).arrChromosomes[i] = booTemp;
return other;
* Mutate individual chromosomes of this individual with certain probability
* In case of knapsack, particular thing is just inserted/taken out of the knapsack
* @see Individual#mutate()
protected void mutate()
//probability of mutation (in percents)
int intMutationProbability = this.evolution.getMutationProbability();
int intChromosomeCount = this.arrChromosomes.length;
//iterate through all chromosomes, mutating them with certain (set) probability
for (int i = 0; i < intChromosomeCount; i++)
//mutation probability passed => mutate this chromosome
if (this.randomizer.nextInt(100) < intMutationProbability)
this.arrChromosomes[i] = !this.arrChromosomes[i];
//when mutation finished, we must check if this individual still suits the assignment;
//if not, repait it
this.check();
* Check if this individual still suits the assignment; if not, repair it
* In case of knapsack it means that sum of weights of things currently in knapsack
* will not exceed capacity of backpack; if exceeds, take out as many things as necessary
* to not to exceed again; choose things to be taken out according to worst weight to price ratio
* @see Individual#check()
protected void check()
int intSumOfWeights = 0;
//list of things in the knapsack sorted by weight to price ratio
//key: index of thing in knapsack
//value: weight/price ratio
TreeMap<Integer, Float> things = new TreeMap<Integer, Float>();
for (int i = 0; i < this.arrChromosomes.length; i++)
//thing in the knapsack
if (this.arrChromosomes[i] == true)
//add its weight to sum of weights
intSumOfWeights += this.assignment.arrWeights[i];
//add it to the list of things sorted by weight to price ratio
things.put(i, (((float) this.assignment.arrWeights[i]) / ((float) this.assignment.arrPrices[i])));
//sum of weights exceeds knapsack capacity => take out as many things as necessary
while (intSumOfWeights > this.assignment.getKnapsackCapacity())
//take out thing with worst weight/price ratio from all things currently in knapsack
this.arrChromosomes[things.lastKey()] = false;
//update sum of weights of things currently in knapsack
intSumOfWeights -= things.get(things.lastKey());
//also remove this thing from list of things
things.remove(things.lastKey());
And another class, where i need this feature (tried to use generics for that, but they can't be used in this way):
* Evolution.java
* Created on 21. leden 2007, 2:47
package genetics;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
* Class for algorithms using simulated evolution to deal with a problem
* Tried to be designed general enough to allow to be used for every genetic algotihm.
* If true, only class Individual must be implemented according to problem to be solved,
* the rest of genetic algorithm stays the same.
* @author Richard V�tek
* @version
public class Evolution<Problem, IndividualClass extends Individual>
   * Number of generations of evolution to finish
protected int intGenerationCount;
   * Number of individuals in each generation
protected int intGenerationSize;
   * Elite individual count
   * All elite individuals are just copied from one generation to another with no change
protected int intGenerationEliteCount;
   * Number of individuals participating a tournament
   * To select an good individual for next generation, tournaments are hold.
   * This affects number of individuals which one good individual is selected
   * from in one tournament.
   * @see <a href="http://cs.felk.cvut.cz/%7Exobitko/ga/example_f.html">Genetic Algorithm Example Applet</a>
protected int intGenerationTournamentSize;
   * Probability of mutation (in percents)
protected int intMutationProbability;
   * Current generation of individuals in evolution
protected Generation<IndividualClass> thisGeneration;
   * Next generation of individuals in evolution
protected Generation<IndividualClass> nextGeneration;
   * Fitness of best individual in this generation
private int intIndividualBestFitness;
   * Sum of fitnesses of all individuals in this generation
private int intIndividualsSumFitness;
   * Fitness of worst individual in this generation
private int intIndividualWorstFitness;
   * Fitness of best elite individual in (every) generation
   * Auxilliary variable to not to count statistics for elite individuals
   * in each generation as well (not needed - elite individuals don't change themselves)
private int intIndividualEliteBestFitness;
   * Sum of fitnesses of all elite individuals in (every) generation
   * Auxilliary variable to not to count statistics for elite individuals
   * in each generation as well (not needed - elite individuals don't change themselves)
private int intIndividualElitesSumFitness;
   * Fitness of worst elite individual in (every) generation
   * Auxilliary variable to not to count statistics for elite individuals
   * in each generation as well (not needed - elite individuals don't change themselves)
private int intIndividualEliteWorstFitness;
   * Create a new instance of Evolution (settings passed through parameters)
   * @param   intGenerationCount            Number of generation of evolution to finish
   * @param   intGenerationSize             Number of individuals in each generation
   * @param   intGenerationEliteRatio       Elite individuals to generation size ratio (in percents)
   * @param   intGenerationTournamentRatio Members of tournament to generation size ratio (in percents)
   * @param   intMutationProbability        Probability of mutation of each chromosome of each individual of generation (in percents)
   * @see     #intGenerationEliteCount
   * @see     #intGenerationTournamentSize
public Evolution(
    int intGenerationCount, int intGenerationSize,
    int intGenerationEliteRatio, int intGenerationTournamentRatio,
    int intMutationProbability)
    this.intGenerationCount = intGenerationCount;
    this.intGenerationSize = intGenerationSize;
    this.intGenerationEliteCount = (int) (intGenerationSize * (intGenerationEliteRatio / 100.0));
    this.intGenerationTournamentSize = (int) (intGenerationSize * (intGenerationTournamentRatio / 100.0));
    this.intMutationProbability = intMutationProbability;
   * Create a new instance of Evolution (settings loaded from settings file)
   * @param   strSettingFile Name of file containing settings for evolution
   * @throws IOException     File does not exist, cannot be read, etc.
   * @throws Exception       Another exception occured during loading of file
public Evolution(String strSettingFile)
    BufferedReader settings;
    String settingsLine;
    int intLineCounter = 0;
    int intSetting;
    try
      settings = new BufferedReader(new FileReader(strSettingFile));
      while ((settingsLine = settings.readLine()) != null)
        intLineCounter++;
        settingsLine = settingsLine.substring(0, settingsLine.indexOf("\t"));
        intSetting = Integer.parseInt(settingsLine);
        switch (intLineCounter)
          case 1:
            this.intGenerationCount = intSetting;
            break;
          case 2:
            this.intGenerationSize = intSetting;
            break;
          case 3:
            this.intGenerationEliteCount = (int) (this.intGenerationSize * (intSetting / 100.0));
            break;
          case 4:
            this.intGenerationTournamentSize = (int) (this.intGenerationSize * (intSetting / 100.0));
            break;
          case 5:
            this.intMutationProbability = intSetting;
            break;
        } //switch
      } //while
      //after reading has been completed, let's close the stream
      settings.close();
    } //try
    //IO exception - file not found, cannot be read, etc.
    catch (IOException ioe)
      System.out.println("Vyskytl se I/O probl�m při nač�t�n� zad�n� ze souboru " + strSettingFile);
    //Exception - another problem during reading of file
    catch (Exception e)
      System.out.printf("Vyskytl se nějak� divn� probl�m při nač�t�n� zad�n� ze souboru %s. V�pis vyj�mky:\n", strSettingFile);
      e.printStackTrace();
   * Vivify first generation for evolution
   * Necessary number of individuals is created with random chromosomes.
   * Their chromosomes must then be checked if they suit the assignment
   * and if not so, repaired.
private Generation<IndividualClass> vivifyFirstGeneration()
    //create a brand-new generation
    Generation generation = new Generation<IndividualClass>(this);
    int intTemp;
    //for all individual of this generation
    for (int i = 0; i < this.intGenerationSize; i++)
//create an individual with no chromosomes
generation.arrIndividuals[i] = new IndividualClass(this, Problem);
      //create a set of random chromosomes
      neration.arrIndividuals.createRandomChromosomes();
//if these chromosomes does not suit assignment, repair them
generation.arrIndividuals[i].check();
//sort Individuals by fitness so elite individuals get to first positions of array
Arrays.sort(generation.arrIndividuals);
//now count statistics for elite individuals (it is enough to count them once,
//elite don't get changed so their statistics don't get changed either)
this.intIndividualEliteBestFitness = Integer.MIN_VALUE;
this.intIndividualElitesSumFitness = 0;
this.intIndividualEliteWorstFitness = Integer.MAX_VALUE;
//count statistics for elite individuals
for (int i = 0; i < this.intGenerationEliteCount; i++)
intTemp = generation.arrIndividuals[i].getFitness();
//better fitness than best fitness so far
if (intTemp > this.intIndividualEliteBestFitness)
this.intIndividualEliteBestFitness = intTemp;
//worse fitness than worst fitness so far
else if (intTemp < this.intIndividualEliteWorstFitness)
this.intIndividualEliteWorstFitness = intTemp;
this.intIndividualElitesSumFitness += intTemp;
//reset generation's statistics
this.intIndividualBestFitness = this.intIndividualEliteBestFitness;
this.intIndividualsSumFitness = this.intIndividualElitesSumFitness;
this.intIndividualWorstFitness = this.intIndividualEliteWorstFitness;
//count generation's statistics also from rest of individuals
for (int i = this.intGenerationEliteCount; i < this.intGenerationSize; i++)
updateGenerationStatistics(generation.arrIndividuals[i].getFitness());
return generation;
* Get next generation in evolution
* Core method for all evolution; Through this method, new generation is obtained.
* Every next generation should contain better individuals than the previous one
* (till certain point) so with growing number of iterations in evolution, we
* get better results (till certain point).
* Everytime all elite individuals are copied to next generation, then hold needed number of
* tournaments to choose a pair of good-looking individuals, cross-breed individuals in these
* pairs, mutate them (and repair if necessary) and finally add to next generation.
* @return Generation Next generation in evolution
* @see Generation#tournament()
* @see Generation#crossbreed()
* @see Generation#mutate()
private Generation getNextGeneration()
Generation nextGeneration = new Generation(this);
//number of pairs of individuals to select for next generation
int intIndividualPairsToSelect = (this.intGenerationSize - this.intGenerationEliteCount) / 2;
int intTemp;
//reset generation's statistics
this.intIndividualBestFitness = this.intIndividualEliteBestFitness;
this.intIndividualsSumFitness = this.intIndividualElitesSumFitness;
this.intIndividualWorstFitness = this.intIndividualEliteWorstFitness;
//just copy all elite individuals from this generation to another
//(they are on first positions of array of individuals)
for (int i = 0; i < this.intGenerationEliteCount; i++)
nextGeneration.arrIndividuals[i] = this.thisGeneration.arrIndividuals[i];
//hold as many tournaments as necessary to select remaining number of pairs
//of good-looking individuals for next generation (apart from the elite ones)
for (int i = 0; i < intIndividualPairsToSelect; i++)
this.thisGeneration.tournament();
this.thisGeneration.crossbreed();
this.thisGeneration.mutate();
//add this individual in next generation
nextGeneration.arrIndividuals[2 * i] = this.thisGeneration.nextGenerationIndividual01;
//update statistics of generation
updateGenerationStatistics(this.thisGeneration.nextGenerationIndividual01.getFitness());
//add this individual in next generation
nextGeneration.arrIndividuals[2 * i + 1] = this.thisGeneration.nextGenerationIndividual02;
//update statistics of generation
updateGenerationStatistics(this.thisGeneration.nextGenerationIndividual02.getFitness());
//next generation is complete => return it
return nextGeneration;
* Update statistics of current generations
* @param intFitness Fitness that may possibly update generation's statistics
* (best fitness, worst fitness, sum of fitnesses)
private void updateGenerationStatistics(int intFitness)
//better fitness than best fitness so far
if (intFitness > this.intIndividualBestFitness)
this.intIndividualBestFitness = intFitness;
//worse fitness than worst fitness so far
else if (intFitness < this.intIndividualWorstFitness)
this.intIndividualWorstFitness = intFitness;
//update sum of fitnesses as well (for average fitness)
this.intIndividualsSumFitness += intFitness;
* Execute evolution process
* Vivify first generation and then as many next generations as set in settings of evolution
public void evolution()
this.thisGeneration = vivifyFirstGeneration();
//output generation's statistics
System.out.printf("Generace 0:\t%d\t%d\t%d", this.getIndividualBestFitness(), this.getIndividualAverageFitness(), this.getIndividualWorstFitness());
for (int i = 0; i < this.intGenerationCount; i++)
this.nextGeneration = getNextGeneration();
this.thisGeneration = this.nextGeneration;
//output generation's statistics
System.out.printf("Generace %d:\t%d\t%d\t%d", i, this.getIndividualBestFitness(), this.getIndividualAverageFitness(), this.getIndividualWorstFitness());
* Get best fitness of all individuals in this generation
public int getIndividualBestFitness()
return intIndividualBestFitness;
* Get average fitness of all individuals in this generation
public float getIndividualAverageFitness()
return (this.intIndividualsSumFitness / (float) this.intGenerationSize);
* Get worst fitness of all individuals in this generation
public int getIndividualWorstFitness()
return intIndividualWorstFitness;
* Get probability of mutation
* @return Probability of mutation of each chromosome of every individual in generation (in percents)
public int getMutationProbability()
return intMutationProbability;

Overriding default implementation of TrustManager class

Similar Messages

Maybe you are looking for