Package org.objectweb.asm

Class Handler

  • final class Handler
extends java.lang.Object
    Information about an exception handler. Corresponds to an element of the exception_table array of a Code attribute, as defined in the Java Virtual Machine Specification (JVMS). Handler instances can be chained together, with their nextHandler field, to describe a full JVMS exception_table array.
    See Also:
    JVMS 4.7.3

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) int catchType
      The catch_type field of this JVMS exception_table entry.
      (package private) java.lang.String catchTypeDescriptor
      The internal name of the type of exceptions handled by this handler, or null to catch any exceptions.
      (package private) Label endPc
      The end_pc field of this JVMS exception_table entry.
      (package private) Label handlerPc
      The handler_pc field of this JVMS exception_table entry.
      (package private) Handler nextHandler
      The next exception handler.
      (package private) Label startPc
      The start_pc field of this JVMS exception_table entry.

    • Constructor Summary

      Constructors 
      Constructor Description
      Handler​(Handler handler, Label startPc, Label endPc)
      Constructs a new Handler from the given one, with a different scope.
      Handler​(Label startPc, Label endPc, Label handlerPc, int catchType, java.lang.String catchTypeDescriptor)
      Constructs a new Handler.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      (package private) static int getExceptionTableLength​(Handler firstHandler)
      Returns the number of elements of the Handler list that begins with the given element.
      (package private) static int getExceptionTableSize​(Handler firstHandler)
      Returns the size in bytes of the JVMS exception_table corresponding to the Handler list that begins with the given element.
      (package private) static void putExceptionTable​(Handler firstHandler, ByteVector output)
      Puts the JVMS exception_table corresponding to the Handler list that begins with the given element.
      (package private) static Handler removeRange​(Handler firstHandler, Label start, Label end)
      Removes the range between start and end from the Handler list that begins with the given element.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • startPc

        final Label startPc
        The start_pc field of this JVMS exception_table entry. Corresponds to the beginning of the exception handler's scope (inclusive).

      • endPc

        final Label endPc
        The end_pc field of this JVMS exception_table entry. Corresponds to the end of the exception handler's scope (exclusive).

      • handlerPc

        final Label handlerPc
        The handler_pc field of this JVMS exception_table entry. Corresponding to the beginning of the exception handler's code.

      • catchType

        final int catchType
        The catch_type field of this JVMS exception_table entry. This is the constant pool index of the internal name of the type of exceptions handled by this handler, or 0 to catch any exceptions.

      • catchTypeDescriptor

        final java.lang.String catchTypeDescriptor
        The internal name of the type of exceptions handled by this handler, or null to catch any exceptions.

      • nextHandler

        Handler nextHandler
        The next exception handler.

    • Constructor Detail

      • Handler

        Handler​(Label startPc,
        Label endPc,
        Label handlerPc,
        int catchType,
        java.lang.String catchTypeDescriptor)
        Constructs a new Handler.
        Parameters:
        startPc - the start_pc field of this JVMS exception_table entry.
        endPc - the end_pc field of this JVMS exception_table entry.
        handlerPc - the handler_pc field of this JVMS exception_table entry.
        catchType - The catch_type field of this JVMS exception_table entry.
        catchTypeDescriptor - The internal name of the type of exceptions handled by this handler, or null to catch any exceptions.

      • Handler

        Handler​(Handler handler,
        Label startPc,
        Label endPc)
        Constructs a new Handler from the given one, with a different scope.
        Parameters:
        handler - an existing Handler.
        startPc - the start_pc field of this JVMS exception_table entry.
        endPc - the end_pc field of this JVMS exception_table entry.

    • Method Detail

      • removeRange

        static Handler removeRange​(Handler firstHandler,
                           Label start,
                           Label end)
        Removes the range between start and end from the Handler list that begins with the given element.
        Parameters:
        firstHandler - the beginning of a Handler list. May be null.
        start - the start of the range to be removed.
        end - the end of the range to be removed. Maybe null.
        Returns:
        the exception handler list with the start-end range removed.

      • getExceptionTableLength

        static int getExceptionTableLength​(Handler firstHandler)
        Returns the number of elements of the Handler list that begins with the given element.
        Parameters:
        firstHandler - the beginning of a Handler list. May be null.
        Returns:
        the number of elements of the Handler list that begins with 'handler'.

      • getExceptionTableSize

        static int getExceptionTableSize​(Handler firstHandler)
        Returns the size in bytes of the JVMS exception_table corresponding to the Handler list that begins with the given element. This includes the exception_table_length field.
        Parameters:
        firstHandler - the beginning of a Handler list. May be null.
        Returns:
        the size in bytes of the exception_table_length and exception_table structures.

      • putExceptionTable

        static void putExceptionTable​(Handler firstHandler,
                              ByteVector output)
        Puts the JVMS exception_table corresponding to the Handler list that begins with the given element. This includes the exception_table_length field.
        Parameters:
        firstHandler - the beginning of a Handler list. May be null.
        output - where the exception_table_length and exception_table structures must be put.