Package org.apache.bcel.generic

This package contains the "generic" part of the Byte Code Engineering Library, i.e., classes to dynamically modify class objects and byte code instructions.

See:
Description

Interface Summary

AllocationInstruction	Denote family of instructions that allocates space in the heap.
ClassObserver	Implement this interface if you're interested in changes to a ClassGen object and register yourself with addObserver().
CompoundInstruction	Wrapper class for `compound' operations, virtual instructions that don't exist as byte code, but give a useful meaning.
ConstantPushInstruction	Denotes a push instruction that produces a literal on the stack such as SIPUSH, BIPUSH, ICONST, etc.
ExceptionThrower	Denote an instruction that may throw a run-time or a linking exception (or both) during execution.
FieldObserver	Imnplement this interface if you're interested in changes to a FieldGen object and register yourself with addObserver().
IndexedInstruction	Denote entity that refers to an index, e.g.
InstructionConstants	This interface contains shareable instruction objects.
InstructionListObserver	Implement this interface if you're interested in changes to an InstructionList object and register yourself with addObserver().
InstructionTargeter	Denote that a class targets InstructionHandles within an InstructionList.
LoadClass	Denotes that an instruction may start the process of loading and resolving the referenced class in the Virtual Machine.
MethodObserver	Implement this interface if you're interested in changes to a MethodGen object and register yourself with addObserver().
NamedAndTyped	Denote entity that has both name and type.
PopInstruction	Denotes an unparameterized instruction to pop a value on top from the stack, such as ISTORE, POP, PUTSTATIC.
PushInstruction	Denotes an unparameterized instruction to produce a value on top of the stack, such as ILOAD, LDC, SIPUSH, DUP, ICONST, etc.
StackConsumer	Denote an instruction that may consume a value from the stack.
StackProducer	Denote an instruction that may produce a value on top of the stack (this excludes DUP_X1, e.g.)
TypedInstruction	Get the type associated with an instruction, int for ILOAD, or the type of the field of a PUTFIELD instruction, e.g..
UnconditionalBranch	Denotes an instruction to perform an unconditional branch, i.e., GOTO, JSR.
VariableLengthInstruction	Denotes an instruction to be a variable length instruction, such as GOTO, JSR, LOOKUPSWITCH and TABLESWITCH.
Visitor	Interface implementing the Visitor pattern programming style.

Class Summary

AALOAD	AALOAD - Load reference from array
AASTORE	AASTORE - Store into reference array
ACONST_NULL	ACONST_NULL - Push null reference
ALOAD	ALOAD - Load reference from local variable
ANEWARRAY	ANEWARRAY - Create new array of references
ARETURN	ARETURN - Return reference from method
ArithmeticInstruction	Super class for the family of arithmetic instructions.
ArrayInstruction	Super class for instructions dealing with array access such as IALOAD.
ARRAYLENGTH	ARRAYLENGTH - Get length of array
ArrayType	Denotes array type, such as int[][]
ASTORE	ASTORE - Store reference into local variable
ATHROW	ATHROW - Throw exception
BALOAD	BALOAD - Load byte or boolean from array
BasicType	Denotes basic type such as int.
BASTORE	BASTORE - Store into byte or boolean array
BIPUSH	BIPUSH - Push byte on stack
BranchHandle	BranchHandle is returned by specialized InstructionList.append() whenever a BranchInstruction is appended.
BranchInstruction	Abstract super class for branching instructions like GOTO, IFEQ, etc..
BREAKPOINT	BREAKPOINT
CALOAD	CALOAD - Load char from array
CASTORE	CASTORE - Store into char array
CHECKCAST	CHECKCAST - Check whether object is of given type
ClassGen	Template class for building up a java class.
CodeExceptionGen	This class represents an exception handler, i.e., specifies the region where a handler is active and an instruction where the actual handling is done.
ConstantPoolGen	This class is used to build up a constant pool.
ConversionInstruction	Super class for the x2y family of instructions.
CPInstruction	Abstract super class for instructions that use an index into the constant pool such as LDC, INVOKEVIRTUAL, etc.
D2F	D2F - Convert double to float
D2I	D2I - Convert double to int
D2L	D2L - Convert double to long
DADD	DADD - Add doubles
DALOAD	DALOAD - Load double from array
DASTORE	DASTORE - Store into double array
DCMPG	DCMPG - Compare doubles: value1 > value2
DCMPL	DCMPL - Compare doubles: value1 < value2
DCONST	DCONST - Push 0.0 or 1.0, other values cause an exception
DDIV	DDIV - Divide doubles
DLOAD	DLOAD - Load double from local variable
DMUL	DMUL - Multiply doubles
DNEG	DNEG - Negate double
DREM	DREM - Remainder of doubles
DRETURN	DRETURN - Return double from method
DSTORE	DSTORE - Store double into local variable
DSUB	DSUB - Substract doubles
DUP	DUP - Duplicate top operand stack word
DUP_X1	DUP_X1 - Duplicate top operand stack word and put two down
DUP_X2	DUP_X2 - Duplicate top operand stack word and put three down
DUP2	DUP2 - Duplicate two top operand stack words
DUP2_X1	DUP2_X1 - Duplicate two top operand stack words and put three down
DUP2_X2	DUP2_X2 - Duplicate two top operand stack words and put four down
EmptyVisitor	Supplies empty method bodies to be overridden by subclasses.
F2D	F2D - Convert float to double
F2I	F2I - Convert float to int
F2L	F2L - Convert float to long
FADD	FADD - Add floats
FALOAD	FALOAD - Load float from array
FASTORE	FASTORE - Store into float array
FCMPG	FCMPG - Compare floats: value1 > value2
FCMPL	FCMPL - Compare floats: value1 < value2
FCONST	FCONST - Push 0.0, 1.0 or 2.0, other values cause an exception
FDIV	FDIV - Divide floats
FieldGen	Template class for building up a field.
FieldGenOrMethodGen	Super class for FieldGen and MethodGen objects, since they have some methods in common!
FieldInstruction	Super class for the GET/PUTxxx family of instructions.
FieldOrMethod	Super class for InvokeInstruction and FieldInstruction, since they have some methods in common!
FLOAD	FLOAD - Load float from local variable
FMUL	FMUL - Multiply floats
FNEG	FNEG - Negate float
FREM	FREM - Remainder of floats
FRETURN	FRETURN - Return float from method
FSTORE	FSTORE - Store float into local variable
FSUB	FSUB - Substract floats
GETFIELD	GETFIELD - Fetch field from object
GETSTATIC	GETSTATIC - Fetch static field from class
GOTO	GOTO - Branch always (to relative offset, not absolute address)
GOTO_W	GOTO_W - Branch always (to relative offset, not absolute address)
GotoInstruction	Super class for GOTO
I2B	I2B - Convert int to byte
I2C	I2C - Convert int to char
I2D	I2D - Convert int to double
I2F	I2F - Convert int to float
I2L	I2L - Convert int to long
I2S	I2S - Convert int to short
IADD	IADD - Add ints
IALOAD	IALOAD - Load int from array
IAND	IAND - Bitwise AND int
IASTORE	IASTORE - Store into int array
ICONST	ICONST - Push value between -1, ..., 5, other values cause an exception
IDIV	IDIV - Divide ints
IF_ACMPEQ	IF_ACMPEQ - Branch if reference comparison succeeds
IF_ACMPNE	IF_ACMPNE - Branch if reference comparison doesn't succeed
IF_ICMPEQ	IF_ICMPEQ - Branch if int comparison succeeds
IF_ICMPGE	IF_ICMPGE - Branch if int comparison succeeds
IF_ICMPGT	IF_ICMPGT - Branch if int comparison succeeds
IF_ICMPLE	IF_ICMPLE - Branch if int comparison succeeds
IF_ICMPLT	IF_ICMPLT - Branch if int comparison succeeds
IF_ICMPNE	IF_ICMPNE - Branch if int comparison doesn't succeed
IFEQ	IFEQ - Branch if int comparison with zero succeeds
IFGE	IFGE - Branch if int comparison with zero succeeds
IFGT	IFGT - Branch if int comparison with zero succeeds
IfInstruction	Super class for the IFxxx family of instructions.
IFLE	IFLE - Branch if int comparison with zero succeeds
IFLT	IFLT - Branch if int comparison with zero succeeds
IFNE	IFNE - Branch if int comparison with zero succeeds
IFNONNULL	IFNONNULL - Branch if reference is not null
IFNULL	IFNULL - Branch if reference is not null
IINC	IINC - Increment local variable by constant
ILOAD	ILOAD - Load int from local variable onto stack
IMPDEP1	IMPDEP1 - Implementation dependent
IMPDEP2	IMPDEP2 - Implementation dependent
IMUL	IMUL - Multiply ints
INEG	INEG - Negate int
INSTANCEOF	INSTANCEOF - Determine if object is of given type
Instruction	Abstract super class for all Java byte codes.
InstructionConstants.Clinit
InstructionFactory	Instances of this class may be used, e.g., to generate typed versions of instructions.
InstructionHandle	Instances of this class give users a handle to the instructions contained in an InstructionList.
InstructionList	This class is a container for a list of Instruction objects.
InvokeInstruction	Super class for the INVOKExxx family of instructions.
INVOKEINTERFACE	INVOKEINTERFACE - Invoke interface method
INVOKESPECIAL	INVOKESPECIAL - Invoke instance method; special handling for superclass, private and instance initialization method invocations
INVOKESTATIC	INVOKESTATIC - Invoke a class (static) method
INVOKEVIRTUAL	INVOKEVIRTUAL - Invoke instance method; dispatch based on class
IOR	IOR - Bitwise OR int
IREM	IREM - Remainder of int
IRETURN	IRETURN - Return int from method
ISHL	ISHL - Arithmetic shift left int
ISHR	ISHR - Arithmetic shift right int
ISTORE	ISTORE - Store int from stack into local variable
ISUB	ISUB - Substract ints
IUSHR	IUSHR - Logical shift right int
IXOR	IXOR - Bitwise XOR int
JSR	JSR - Jump to subroutine
JSR_W	JSR_W - Jump to subroutine
JsrInstruction	Super class for JSR - Jump to subroutine
L2D	L2D - Convert long to double
L2F	L2F - Convert long to float
L2I	L2I - Convert long to int
LADD	LADD - Add longs
LALOAD	LALOAD - Load long from array
LAND	LAND - Bitwise AND longs
LASTORE	LASTORE - Store into long array
LCMP	LCMP - Compare longs:
LCONST	LCONST - Push 0 or 1, other values cause an exception
LDC	LDC - Push item from constant pool.
LDC_W	LDC_W - Push item from constant pool (wide index)
LDC2_W	LDC2_W - Push long or double from constant pool
LDIV	LDIV - Divide longs
LineNumberGen	This class represents a line number within a method, i.e., give an instruction a line number corresponding to the source code line.
LLOAD	LLOAD - Load long from local variable
LMUL	LMUL - Multiply longs
LNEG	LNEG - Negate long
LoadInstruction	Denotes an unparameterized instruction to load a value from a local variable, e.g.
LocalVariableGen	This class represents a local variable within a method.
LocalVariableInstruction	Abstract super class for instructions dealing with local variables.
LOOKUPSWITCH	LOOKUPSWITCH - Switch with unordered set of values
LOR	LOR - Bitwise OR long
LREM	LREM - Remainder of long
LRETURN	LRETURN - Return long from method
LSHL	LSHL - Arithmetic shift left long
LSHR	LSHR - Arithmetic shift right long
LSTORE	LSTORE - Store long into local variable
LSUB	LSUB - Substract longs
LUSHR	LUSHR - Logical shift right long
LXOR	LXOR - Bitwise XOR long
MethodGen	Template class for building up a method.
MONITORENTER	MONITORENTER - Enter monitor for object
MONITOREXIT	MONITOREXIT - Exit monitor for object
MULTIANEWARRAY	MULTIANEWARRAY - Create new mutidimensional array of references
NEW	NEW - Create new object
NEWARRAY	NEWARRAY - Create new array of basic type (int, short, ...)
NOP	NOP - Do nothing
ObjectType	Denotes reference such as java.lang.String.
POP	POP - Pop top operand stack word
POP2	POP2 - Pop two top operand stack words
PUSH	Wrapper class for push operations, which are implemented either as BIPUSH, LDC or xCONST_n instructions.
PUTFIELD	PUTFIELD - Put field in object
PUTSTATIC	PUTSTATIC - Put static field in class
ReferenceType	Super class for objects and arrays.
RET	RET - Return from subroutine
RETURN	RETURN - Return from void method
ReturnaddressType	Returnaddress, the type JSR or JSR_W instructions push upon the stack.
ReturnInstruction	Super class for the xRETURN family of instructions.
SALOAD	SALOAD - Load short from array
SASTORE	SASTORE - Store into short array
Select	Select - Abstract super class for LOOKUPSWITCH and TABLESWITCH instructions.
SIPUSH	SIPUSH - Push short
StackInstruction	Super class for stack operations like DUP and POP.
StoreInstruction	Denotes an unparameterized instruction to store a value into a local variable, e.g.
SWAP	SWAP - Swa top operand stack word
SWITCH	SWITCH - Branch depending on int value, generates either LOOKUPSWITCH or TABLESWITCH instruction, depending on whether the match values (int[]) can be sorted with no gaps between the numbers.
TABLESWITCH	TABLESWITCH - Switch within given range of values, i.e., low..high
Type	Abstract super class for all possible java types, namely basic types such as int, object types like String and array types, e.g.

Exception Summary

ClassGenException	Thrown on internal errors.
TargetLostException	Thrown by InstructionList.remove() when one or multiple disposed instruction are still being referenced by a InstructionTargeter object.

Package org.apache.bcel.generic Description

This package contains the "generic" part of the Byte Code Engineering Library, i.e., classes to dynamically modify class objects and byte code instructions.