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how to invoke java class name given in xml tag.?  RSS feed

 
tarun sapra
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Hi everyone,

i was curious to know how can we invoke a java class , whose name is given with in an xml tag
like,
<class>com.example.HelloWorld</class>
this thing is also used in web.xml by the web containers , is it implemented using JAXB???
 
Bear Bibeault
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It's pretty easy if the class has a nullary constructor.

Check out the methods to the Class class.

For more complex objects, check out the reflection API.
 
tarun sapra
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hi..thanks for the reply..but can you please share some code example?..as it's still not clear to me ...how exactly like the container or other softwares are able to invoke java classes written as data inside xml tags..
 
Bear Bibeault
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You're going to have to show some effort on your own. Did you look at the javadoc for the Class class?

Hints:
  • Find a method that can create a Class instance out of the string name of the class
  • Find a method that can create instances


  • You won't get anywhere if you have to depend on others to do your work for you.
     
    Ulf Dittmer
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    Class.forName(...).newInstance() will create an object from a fully-qualified class name, provided the class has a no-argument constructor. To do much useful with it (without using reflection) you'll need to cast it to some interface that it implements, though.
     
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