Runnable and Thead Class

what is the Advantages of using Runnable Interface and the Thread Class?
Please let me know this....and when to use which one..
Thanks
satish

It should be explained in any decent tutorial or Book:
http://java.sun.com/docs/books/tutorial/
http://java.sun.com/learning/new2java/index.html
http://javaalmanac.com
http://www.jguru.com
http://www.javaranch.com
Bruce Eckel's Thinking in Java
Joshua Bloch's Effective Java
Bert Bates and Kathy Sierra's Head First Java
But in case none of the above explains it the short version is that unless you actually need to change Threads behavior (i.e., override one or more of its methods, or add new methods) then you should use Runnable.

Similar Messages

Runnable Vs Thread Class

Hello All,
I have a doubt regarding Runnable and Thread class. As we all know Java provides two ways to run Threads. One way is to extend Thread class and the other way is to implement Runnable Interface.
Apart from the OOPS funda, does java have any other concept in providing two ways to run threads ?. I mean, we very well know that if we extend Thread class, we may not be able to extend any other class in Java . So if we implement Runnable interface,we can extend or implement any other Interface or class. Apart from this reason, does Java has any other concept in providing two ways to run threads ??
Please share your knowledge
Thanks and Have a Nice Day,
Regds,
Sai

As far as I know, that's the only reason for the two options--one gives you flexibility in your class hierarchy, the other saves you a few lines of code. Personally, I always implement Runnable. The few lines of code saved seem trivial to me compared to "cleaner" OO (IMHO), but maybe somebody else has a better reason to extend Thread.

Runnable JAR, Main-Class, Class-Path and INDEX.LST

Some funky finding, don't know whether this is a bug or a feature...
I'm using
java version "1.4.2_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
Java HotSpot(TM) Client VM (build 1.4.2_06-b03, mixed mode)
I observed follwing weired behaviour:
If you have a JAR packed with your classes and define in the Manifest a Main-Class and a Class-path pointing to JARs in the same directory than the main JAR, example:
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.6.2
Created-By: 1.4.2_06-b03 (Sun Microsystems Inc.)
Main-Class: main.Main
Class-Path: activation.jar axis.jar commons-discovery.jar
commons-logging.jar jaxrpc.jar log4j-1.2.8.jar mail.jar saaj.jar wsd
l4j.jar junit.jarTHEN you should NOT have a META-INF/INDEX.LST file. This file is created for instance by ant jar when setting attribute index="true". Itt complies to the JAR standard and is used to find classes faster.
If you have such a file then none of the classes of the "Class-Path" JARs will be found. At least that was true for me...
Hope, I haven't bothered you with something commonly knwown. Just wanted to let you know, to avoid fighting againt JARs like I did for the last 3 hours..damn.
Cheers,
Peter

Does anyone know if having a Class-Path in the manifest would ignore the system environment variable CLASSPATH?
I'm seeing this in my set-up. I have an external jar file that can be seen if copied to <jre dir>/lib/ext, but when it's in another dir with the CLASSPATH pointing to it can't be found.
My applet uses a number of jar files and I reference them in the manifest using the Class-Path entry. Does this supercede the environment variable??

Trouble with keyboad events and thead

hi ,
i am havin a poblem with keyboad events and thead.
i have used t.start() in the keyreleased event but the thread runs only for 1st keyreleased event then when i again release any key it gives me a run time error as follows.
Exception in thread "AWT-EventQueue-0" java.lang.IllegalThreadStateException
at java.lang.Thread.start(Unknown Source)
at snake.key(snake.java:67)
at snake.keyReleased(snake.java:34)
at java.awt.Component.processKeyEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Window.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Sour
ce)
please help me out .

You might want to reschedule a timer task instead of trying to start a thread again. Or you could modify your thread class in a way that you
- check whether it's already running
- if so, stop it
- initialize the countdown or whatever you do
- start it

Using Timer and TimerTask classes in EJB's(J2EE)

Does J2EE allow us to use Timer and TimerTask classes from java.util package in SessionBean EJB's ( Statless or Statefull )?.
If J2EE does allow, I am not sure how things work in practical, Lets take simple example where a stateless SessionBean creates a Timer class
and schedules a task to be executed after 5 hours and returns. Assuming
GC kicks in many times in 5 hours, I wonder if the Timer object created by survives the GC run's so that it can execute the scheduled tasks.
My gut feeling says that the Timer Object will not survive.. Just
want to confirm that.
I will be interested to know If there are any techiniques that can make
the usage of Timer and TimeTask classes in EJB's possible as well as reliable with minmum impact on over all performance.

Have a look at J2EE 1.4. I think they add a timer service for EJBs there...
Kai

Whats the difference between an INTERFACE and a CLASS?

Whats the difference between an INTERFACE and a CLASS?
Please help.
Thanx.

http://search.java.sun.com/search/java/index.jsp?col=javaforums&qp=%2Bforum%3A31&qt=Difference+between+interface+and+class

Page Attributes and Application Class Attributes

Hi, everyone,
I am quite new to BSP.
I have a question here:
what is the difference between page attributes and application class attributes of a bsp application? As they are both global attributes, there seems to be no big difference when we use them.
thanks a lot.
Fan

Hi Fan,
a BSP application can be made up of many pages.
A page attribute is visible only in the page it is associated with.
Attributes of the application class are visible from every page in that application.
Cheers
Graham Robbo

What is the difference between document class and normal class

Hi,
Please let me know what is the difference between document class and normal class.
And I have no idea which class should call as document class or call as an object.
Thanks
-Actionscript Developer

the document class is invoked immediately when your swf opens. the document class must subclass the sprite or movieclip class.
all other classes are invoked explicitly with code and need not subclass any other class.

How to get the jar file without knowing its name and any class inside it?

Hello, everybody!
I would like to know if there's a way to get a reference programatically to the initial jar without knowing its name and any class contained in it. By "initial jar" I mean the jar that was called in the prompt, like this:
java -jar jarfile.jaror in another way, in a graphical system. To be sincere what I really want is to get a reference to the jar's manifest, but I know if I can get a reference to the jar I can get a reference to its manifest file. Or if you know a way to get the manifest directly, it would also help. So, is there a way to do this?
Thank you.
Marcos

jverd wrote:
marcos_aps wrote:
abillconsl wrote:
Can you be more specific - IOW, can you cite a specific case?Absolutely. I want to access the jar in source code with the java.util.zip.JarFile class, for example.But why? You still haven't provided a use case or explained what you're trying to accomplish. As already pointed out, whatever you're trying to do, this is a brittle solution. If you explain what you're trying to accomplish with this, somebody may be able to suggest a better approach.jverd, I explained for baftos. Anyway, I will try to be more specific. I start my sytem like this, from, say, for example, jar1.jar:
import br.product.System;
public static void main(String[] args)
System.start("NameOfTheSystem");
}The System class is in util.jar, for example. This jar is used by all systems. I wouldn't like to pass in the name of the system, as above. I would like that the System class could read it from jar1.jar's manifest file. I just would like to have this:
import br.product.System;
public static void main(String[] args)
System.start();
}It is more elegant and I don't have the name of the system in two places: code and manifest file.
Marcos

Problem in generic value copier class / reflection and generic classes

Hello experts,
I try to archive the following and am struggling for quite some time now. Can someone please give an assessment if this is possible:
I am trying to write a generic data copy method. It searches for all (parameterless) getter methods in the source object that have a corresponding setter method (with same name but prefixed by "set" instead of "get" and with exactly one parameter) in the destination object.
For each pair I found I do the following: If the param of the setter type (T2) is assignable from the return type of the getter (T1), I just assign the value. If the types are not compatible, I want to instantiate a new instance of T2, assign it via the setter, and invoke copyData recursively on the object I get from the getter (as source) and the newly created instance (as destination). The assumption is here, that the occurring source and destination objects are incompatible but have matching getter and setter names and at the leaves of the object tree, the types of the getters and setters are compatible so that the recursion ends.
The core of the problem I am struggling with is the step where I instantiate the new destination object. If T2 is a non-generic type, this is straightforward. However, imagine T1 and T2 are parametrized collections: T1 is List<T3> and T2 is List<T4>. Then I need special handling of the collection. I can easily iterate over the elements of the source List and get the types of the elements, but I can not instantiate only a generic version of the destinatino List. Further I cannot create elements of T4 and add it to the list of T2 and go into recursion, since the information that the inner type of the destination list is T4 is not available at run-time.
public class Source {
   T1 getA();
   setA(T1 x);
public class Dest {
   T2 getA();
   setA(T2 x);
public class BeanDataCopier {
   public static void copyData(Object source, Object destination) {
      for (Method getterMethod : sourceGetterMethods) {
         ... // find matching getter and setter names
         Class sourceParamT = [class of return value of the getter];
         Class destParamT = [class of single param of the setter];
         // special handling for collections - I could use some help here
         // if types are not compatible
         Object destParam = destination.getClass().newInstance();
         Object sourceParam = source.[invoke getter method];
         copyData(sourceParam, destParam);
// usage of the method
Souce s = new Source(); // this is an example, I do not know the type of s at copying time
Dest d = new Dest(); // the same is true for d
// initialize s in a complicated way (actually JAX-B does this)
// copy values of s to d
BeanDataCopier.copyData(s, d);
// now d should have copied values from s Can you provide me with any alternative approaches to implement this "duck typing" behaviour on copying properties?
Best regards,
Patrik
PS: You might have guessed my overall use case: I am sending an object tree over a web service. On the server side, the web service operation has a deeply nested object structure as the return type. On the client side, these resulting object tree has instances not of the original classes, but of client classes generated by axis. The original and generated classes are of different types but have the identically named getter and setter methods (which again have incompatible parameter types that however have consistent names). On the client side, I want to simply create an object of the original class and have the values of the client object (including the whole object tree) copied into it.
Edited by: Patrik_Spiess on Sep 3, 2008 5:09 AM

As I understand your use case this is already supported by Axis with beanMapping [http://ws.apache.org/axis/java/user-guide.html#EncodingYourBeansTheBeanSerializer]
- Roy

Problems using different tables for base class and derived class

I have a class named SuperProject and another class Project derived from
it. If I let SchemaTool generate the tables without specifying a "table"
extension, I get a single TABLE with all the columns from both classes and
everything works fine. But if I specify a "table" for the derived class,
SchemaTool generates the derived class with just one column (corresponds
to the attribute in derived class). Also it causes problems in using the
Project class in collection attributes.
JDO file:
<jdo>
<package name="jdo">
<class name="Project" identity-type="application"
persistence-capable-superclass="SuperProject">
<extension vendor-name="kodo" key="table" value="PROJECT"/>
</class>
<class name="SuperProject" identity-type="application"
objectid-class="ProjectId">
<field name="id" primary-key="true"/>
</class>
</package>
</jdo>
java classes:
public class Project extends SuperProject
String projectSpecific
public class SuperProject
BigDecimal id;
String name;
tables generated by SchemaTool:
TABLE SUPERPROJECTSX (IDX, JDOCLASSX, JDOLOCKX, NAMEX);
TABLE PROJECT(PROJECTSPECIFICX)
Thanks,
Justine Thomas

Justine,
This will be resolved in 2.3.4, to be released later this evening.
-Patrick
In article <aofo2q$mih$[email protected]>, Justine Thomas wrote:
I have a class named SuperProject and another class Project derived from
it. If I let SchemaTool generate the tables without specifying a "table"
extension, I get a single TABLE with all the columns from both classes and
everything works fine. But if I specify a "table" for the derived class,
SchemaTool generates the derived class with just one column (corresponds
to the attribute in derived class). Also it causes problems in using the
Project class in collection attributes.
JDO file:
<jdo>
<package name="jdo">
<class name="Project" identity-type="application"
persistence-capable-superclass="SuperProject">
<extension vendor-name="kodo" key="table" value="PROJECT"/>
</class>
<class name="SuperProject" identity-type="application"
objectid-class="ProjectId">
<field name="id" primary-key="true"/>
</class>
</package>
</jdo>
java classes:
public class Project extends SuperProject
String projectSpecific
public class SuperProject
BigDecimal id;
String name;
tables generated by SchemaTool:
TABLE SUPERPROJECTSX (IDX, JDOCLASSX, JDOLOCKX, NAMEX);
TABLE PROJECT(PROJECTSPECIFICX)
Thanks,
Justine Thomas
Patrick Linskey [email protected]
SolarMetric Inc. http://www.solarmetric.com

Data class and Delivery class in ABAP Dictionary

Hi all,
I want to know the exact information about Data class and Delivery class in ABAP Dictionary
Moderator message : Search for available information. Thread locked.
Edited by: Vinod Kumar on Aug 3, 2011 1:35 PM

As your name Suggests, there were exactly 21 rajapandian already who wanted exact information about Data class and Delivery class. Fortunately some has found the information by own and some were dumped by SAP Police.
Cheers
Amit

BOR Object and ABAP Class

Hi,
Can anybody say when to use BOR object and Abap class in the task with an example.
Thanks,
Mugundhan

There is no any specific condition or rule that for this purpose you need to use BOR and Class , it depends on your requirement. not only the requirement but also the new techniques to make classes not just as simple way to create objects but when you use classes in the Workflows they are not simple classes but they are BUSINESS CLASSES which makes a lot of difference.
Check the blogs of [Jocelyn Dart|https://www.sdn.sap.com/irj/scn/wiki?path=/pages/viewpage.action%3fpageid=55566]

Difference between narrow() method usage and simple class cast for EJB

Hi,
I have a very simple question:
what is the difference between PortableRemoteObject.narrow(fromObj,
toClass) method usage and simple class cast for EJB.
For example,
1)
EJBObject ejbObj;
// somewhere in the code the home.create() called for bean ...
ABean a = (ABean)PortableRemoteObject.narrow(ejbObj,ABean.class);
OR
2)
EJBObject bean;
// somewhere in the code the home.create() called for bean ...
ABean a = (ABean)ejbObj;
Which one is better?
P.S. I'm working with WL 6.1 sp2
Any help would be appreciated.
Thanks in advance,
Orly

[email protected] (Orly) writes:
Hi,
I have a very simple question:
what is the difference between PortableRemoteObject.narrow(fromObj,
toClass) method usage and simple class cast for EJB.
For example,
1)
EJBObject ejbObj;
// somewhere in the code the home.create() called for bean ...
ABean a = (ABean)PortableRemoteObject.narrow(ejbObj,ABean.class);
OR
2)
EJBObject bean;
// somewhere in the code the home.create() called for bean ...
ABean a = (ABean)ejbObj;
Which one is better?(1) is mandated by the spec. It is required because CORBA systems may
not have sufficient type information available to do a simple case.
P.S. I'm working with WL 6.1 sp2 You should always use PRO.narrow()
andy

[svn:bz-trunk] 22429: Adding the default fallback of serializer and deserializer classes to amf deserializer and amf serializer

Revision: 22429
Revision: 22429
Author:   [email protected]
Date:     2011-09-07 08:04:46 -0700 (Wed, 07 Sep 2011)
Log Message:
Adding the default fallback of serializer and deserializer classes to amf deserializer and amf serializer
Modified Paths:
    blazeds/trunk/modules/core/src/flex/messaging/io/SerializationContext.java

Runnable and Thead Class

Similar Messages

Maybe you are looking for