Class EngineUtils

java.lang.Object
org.apache.bsf.util.EngineUtils

public class EngineUtils extends Object
This class contains utilities that language integrators can use when implementing the BSFEngine interface.
Author:
Sanjiva Weerawarana, Sam Ruby, Rony G. Flatscher (added addEventListenerReturningEventInfos)
  • Constructor Details

    • EngineUtils

      public EngineUtils()
  • Method Details

    • addEventListener

      public static void addEventListener(Object bean, String eventSetName, String filter, BSFEngine engine, BSFManager manager, String source, int lineNo, int columnNo, Object script) throws BSFException
      Add a script as a listener to some event coming out of an object. The first two args identify the src of the event and the event set and the rest identify the script which should be run when the event fires.
      Parameters:
      bean - event source
      eventSetName - name of event set from event src to bind to
      filter - filter for events
      engine - BSFEngine which can run this script
      manager - BSFManager of the above engine
      source - (context info) the source of this expression (e.g., filename)
      lineNo - (context info) the line number in source for expr
      columnNo - (context info) the column number in source for expr
      script - the script to execute when the event occurs
      Throws:
      BSFException - if anything goes wrong while running the script
    • addEventListenerReturningEventInfos

      public static void addEventListenerReturningEventInfos(Object bean, String eventSetName, String filter, BSFEngine engine, BSFManager manager, String source, int lineNo, int columnNo, Object script, Object dataFromScriptingEngine) throws BSFException
      Add a script as a listener to some event coming out of an object. The first two args identify the src of the event and the event set and the rest identify the script which should be run when the event fires. The processing will use the engine's apply() method.
      Parameters:
      bean - event source
      eventSetName - name of event set from event src to bind to
      filter - filter for events
      engine - BSFEngine which can run this script
      manager - BSFManager of the above engine
      source - (context info) the source of this expression (e.g., filename)
      lineNo - (context info) the line number in source for expr
      columnNo - (context info) the column number in source for expr
      script - the script to execute when the event occurs
      dataFromScriptingEngine - this contains any object supplied by the scripting engine and gets sent back with the supplied script, if the event occurs. This could be used e.g. for indicating to the scripting engine which scripting engine object/routine/function/procedure should be ultimately informed of the event occurrence.
      Throws:
      BSFException - if anything goes wrong while running the script
    • callBeanMethod

      public static Object callBeanMethod(Object bean, String methodName, Object[] args) throws BSFException
      Finds and invokes a method with the given signature on the given bean. The signature of the method that's invoked is first taken as the types of the args, but if that fails, this tries to convert any primitive wrapper type args to their primitive counterparts to see whether a method exists that way. If it does, done.
      Parameters:
      bean - the object on which to invoke the method
      methodName - name of the method
      args - arguments to be given to the method
      Returns:
      the result of invoking the method, if any
      Throws:
      BSFException - if something goes wrong
    • createBean

      public static Object createBean(String className, Object[] args) throws BSFException
      Creates a new bean. The signature of the constructor that's invoked is first taken as the types of the args, but if that fails, this tries to convert any primitive wrapper type args to their primitive counterparts to see whether a method exists that way. If it does, done.
      Parameters:
      className - fully qualified name of class to instantiate
      args - array of constructor args (or null if none)
      Returns:
      the created bean
      Throws:
      BSFException - if something goes wrong (@see org.apache.cs.util.MethodUtils for the real exceptions that can occur).
    • getTypeSignatureString

      public static String getTypeSignatureString(Class cl)
      Given a class return the type signature string fragment for it. That is, return "I" for int, "J" for long, ... etc..
      Parameters:
      cl - class object for whom the signature fragment is needed.
      Returns:
      the string representing the type signature
    • loadClass

      public static Class loadClass(BSFManager mgr, String name) throws BSFException
      Load a class using the class loader of given manager. If that fails try using a class loader that loads from the tempdir of the manager.
      Parameters:
      mgr - BSFManager who's classLoader and tempDir props are consulted
      name - name of the class to load
      Returns:
      the loaded class
      Throws:
      BSFException - if something goes wrong.