org.extex.unit.dynamic.java
Class JavaLoad

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.unit.dynamic.java.JavaLoad

All Implemented Interfaces:

java.io.Serializable, Code, Loader

public class JavaLoad
extends AbstractCode
implements Loader

This primitive initiates the loading of Java code and implements the primitive \javaload.

The Primitive \javaload

The primitive \javaload loads a java class and invokes its init() method. With this method it is possible to load larger extensions of ExTeX in one junk. There is no need to declare each single macro with \javadef.

Syntax

The general form of this primitive is

   ⟨javaload⟩
       → \javaload ⟨tokens⟩  

The ⟨tokens⟩ is any specification of a list of tokens like a constant list enclosed in braces or a token register. The value of these tokens are taken and interpreted as the name of a Java class. This class is loaded if needed, instantiated, and its method init() is invoked. The instantiation requires the empty constructor to be visible.

Examples

The following example illustrates the use of this primitive:

   \javaload{org.extex.extensions.Basic} 

For the loading of the Java class it is necessary that this Java class implements the interface Loadable.

   package my.package;

   import org.extex.interpreter.contect.Context;
   import org.extex.interpreter.primitives.dynamic.java.Loadable;
   import org.extex.typesetter.Typesetter;
   import org.extex.util.exception.GeneralException;

   class MyModule implements Loadable {

     public MyModule() {
       super();
       // initialization code – if required
     }

     public void init(final Context context,
                      final Typesetter typesetter
                     ) throws GeneralException {
       // implement the initialization code here
     }
   } 

Version:

$Revision: 6447 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

JavaLoad()
Creates a new object.

JavaLoad(CodeToken token)
Creates a new object.

Method Summary

void	execute(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.
void	load(Context context, TokenSource source, Typesetter typesetter) Perform a load operation.

Methods inherited from class org.extex.interpreter.type.AbstractCode

getLocalizer, getName, getToken, isIf, isOuter, readResolve, toString, toText, toText

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

serialVersionUID

protected static final long serialVersionUID

The constant serialVersionUID contains the id for serialization.

See Also:

Constant Field Values

Constructor Detail

JavaLoad

public JavaLoad()

Creates a new object. This method is needed for the nativeload wrapper.

JavaLoad

public JavaLoad(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

execute

public void execute(Flags prefix,
                    Context context,
                    TokenSource source,
                    Typesetter typesetter)
             throws HelpingException,
                    TypesetterException

This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.

Specified by:

execute in interface Code

Overrides:

execute in class AbstractCode

Parameters:

prefix - the prefix controlling the execution

context - the interpreter context

source - the token source

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

AbstractCode.execute( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

load

public void load(Context context,
                 TokenSource source,
                 Typesetter typesetter)
          throws HelpingException,
                 TypesetterException

Perform a load operation.

Specified by:

load in interface Loader

Parameters:

context - the interpreter context

source - the source for new tokens

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

Loader.load( org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)