# Class InstructionFactory

java.lang.Object
org.apache.bcel.generic.InstructionFactory

All Implemented Interfaces:
  `InstructionConstants`

public class InstructionFactory extends Object implements InstructionConstants
Instances of this class may be used, for example, to generate typed versions of instructions. Its main purpose is to be used as the byte code generating backend of a compiler. You can subclass it to add your own create methods.

Note: The static createXXX methods return singleton instances from the `InstructionConst` class.

See Also:
  - `Const`
  - `InstructionConst`

- ## Nested Class Summary

  ### Nested classes/interfaces inherited from interface InstructionConstants

  `InstructionConstants.Clinit`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected ClassGen`
  `cg`
  Deprecated.
  (since 6.0) will be made private; do not access directly, use getter/setter
  `protected ConstantPoolGen`
  `cp`
  Deprecated.
  (since 6.0) will be made private; do not access directly, use getter/setter

  ### Fields inherited from interface InstructionConstants

  `AALOAD, AASTORE, ACONST_NULL, ALOAD_0, ALOAD_1, ALOAD_2, ARETURN, ARRAYLENGTH, ASTORE_0, ASTORE_1, ASTORE_2, ATHROW, BALOAD, BASTORE, bla, CALOAD, CASTORE, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DMUL, DNEG, DREM, DRETURN, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FMUL, FNEG, FREM, FRETURN, FSUB, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, ILOAD_0, ILOAD_1, ILOAD_2, IMUL, INEG, INSTRUCTIONS, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE_0, ISTORE_1, ISTORE_2, ISUB, IUSHR, IXOR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDIV, LMUL, LNEG, LOR, LREM, LRETURN, LSHL, LSHR, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, NOP, POP, POP2, RETURN, SALOAD, SASTORE, SWAP, THIS`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `InstructionFactory(ClassGen cg)`
  Initialize with ClassGen object
  `InstructionFactory(ClassGen cg, ConstantPoolGen cp)`
  `InstructionFactory(ConstantPoolGen cp)`
  Initialize just with ConstantPoolGen object

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Instruction`
  `createAppend(Type type)`
  `static ArrayInstruction`
  `createArrayLoad(Type type)`
  `static ArrayInstruction`
  `createArrayStore(Type type)`
  `static ArithmeticInstruction`
  `createBinaryOperation(String op, Type type)`
  Create binary operation for simple basic types, such as int and float.
  `static BranchInstruction`
  `createBranchInstruction(short opcode, InstructionHandle target)`
  Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH.
  `Instruction`
  `createCast(Type srcType, Type destType)`
  Create conversion operation for two stack operands, this may be an I2C, instruction, for example, if the operands are basic types and CHECKCAST if they are reference types.
  `CHECKCAST`
  `createCheckCast(ReferenceType t)`
  `Instruction`
  `createConstant(Object value)`
  Uses PUSH to push a constant value onto the stack.
  `static StackInstruction`
  `createDup(int size)`
  `static StackInstruction`
  `createDup_1(int size)`
  `static StackInstruction`
  `createDup_2(int size)`
  `FieldInstruction`
  `createFieldAccess(String className, String name, Type type, short kind)`
  Create a field instruction.
  `GETFIELD`
  `createGetField(String className, String name, Type t)`
  `GETSTATIC`
  `createGetStatic(String className, String name, Type t)`
  `INSTANCEOF`
  `createInstanceOf(ReferenceType t)`
  `InvokeInstruction`
  `createInvoke(String className, String name, Type retType, Type[] argTypes, short kind)`
  Create an invoke instruction.
  `InvokeInstruction`
  `createInvoke(String className, String name, Type retType, Type[] argTypes, short kind, boolean useInterface)`
  Create an invoke instruction.
  `static LocalVariableInstruction`
  `createLoad(Type type, int index)`
  `NEW`
  `createNew(String s)`
  `NEW`
  `createNew(ObjectType t)`
  `Instruction`
  `createNewArray(Type t, short dim)`
  Create new array of given size and type.
  `static Instruction`
  `createNull(Type type)`
  Create "null" value for reference types, 0 for basic types like int
  `static StackInstruction`
  `createPop(int size)`
  `InstructionList`
  `createPrintln(String s)`
  Create a call to the most popular System.out.println() method.
  `PUTFIELD`
  `createPutField(String className, String name, Type t)`
  `PUTSTATIC`
  `createPutStatic(String className, String name, Type t)`
  `static ReturnInstruction`
  `createReturn(Type type)`
  Create typed return
  `static LocalVariableInstruction`
  `createStore(Type type, int index)`
  `static Instruction`
  `createThis()`
  Create reference to 'this'
  `ClassGen`
  `getClassGen()`
  `ConstantPoolGen`
  `getConstantPool()`
  `void`
  `setClassGen(ClassGen c)`
  `void`
  `setConstantPool(ConstantPoolGen c)`

  ### Methods inherited from class Object

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

- ## Field Details

  - ### cg

    @Deprecated protected ClassGen cg
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getter/setter

  - ### cp

    @Deprecated protected ConstantPoolGen cp
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getter/setter

- ## Constructor Details

  - ### InstructionFactory

    public InstructionFactory(ClassGen cg)
    Initialize with ClassGen object

  - ### InstructionFactory

    public InstructionFactory(ClassGen cg, ConstantPoolGen cp)

  - ### InstructionFactory

    public InstructionFactory(ConstantPoolGen cp)
    Initialize just with ConstantPoolGen object

- ## Method Details

  - ### createArrayLoad

    public static ArrayInstruction createArrayLoad(Type type)
    Parameters:
      `type` - type of elements of array, i.e., array.getElementType()

  - ### createArrayStore

    public static ArrayInstruction createArrayStore(Type type)
    Parameters:
      `type` - type of elements of array, i.e., array.getElementType()

  - ### createBinaryOperation

    public static ArithmeticInstruction createBinaryOperation(String op, Type type)
    Create binary operation for simple basic types, such as int and float.
    Parameters:
      `op` - operation, such as "+", "*", "<<", etc.

  - ### createBranchInstruction

    public static BranchInstruction createBranchInstruction(short opcode, InstructionHandle target)
    Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH. For those you should use the SWITCH compound instruction.

  - ### createDup

    public static StackInstruction createDup(int size)
    Parameters:
      `size` - size of operand, either 1 (int, for example) or 2 (double)

  - ### createDup_1

    public static StackInstruction createDup_1(int size)
    Parameters:
      `size` - size of operand, either 1 (int, for example) or 2 (double)

  - ### createDup_2

    public static StackInstruction createDup_2(int size)
    Parameters:
      `size` - size of operand, either 1 (int, for example) or 2 (double)

  - ### createLoad

    public static LocalVariableInstruction createLoad(Type type, int index)
    Parameters:
      `index` - index of local variable

  - ### createNull

    public static Instruction createNull(Type type)
    Create "null" value for reference types, 0 for basic types like int

  - ### createPop

    public static StackInstruction createPop(int size)
    Parameters:
      `size` - size of operand, either 1 (int, for example) or 2 (double)

  - ### createReturn

    public static ReturnInstruction createReturn(Type type)
    Create typed return

  - ### createStore

    public static LocalVariableInstruction createStore(Type type, int index)
    Parameters:
      `index` - index of local variable

  - ### createThis

    public static Instruction createThis()
    Create reference to 'this'

  - ### createAppend

    public Instruction createAppend(Type type)

  - ### createCast

    public Instruction createCast(Type srcType, Type destType)
    Create conversion operation for two stack operands, this may be an I2C, instruction, for example, if the operands are basic types and CHECKCAST if they are reference types.

  - ### createCheckCast

    public CHECKCAST createCheckCast(ReferenceType t)

  - ### createConstant

    public Instruction createConstant(Object value)
    Uses PUSH to push a constant value onto the stack.
    Parameters:
      `value` - must be of type Number, Boolean, Character or String

  - ### createFieldAccess

    public FieldInstruction createFieldAccess(String className, String name, Type type, short kind)
    Create a field instruction.
    Parameters:
      `className` - name of the accessed class
      `name` - name of the referenced field
      `type` - type of field
      `kind` - how to access, i.e., GETFIELD, PUTFIELD, GETSTATIC, PUTSTATIC
    See Also:
      - `Const`

  - ### createGetField

    public GETFIELD createGetField(String className, String name, Type t)

  - ### createGetStatic

    public GETSTATIC createGetStatic(String className, String name, Type t)

  - ### createInstanceOf

    public INSTANCEOF createInstanceOf(ReferenceType t)

  - ### createInvoke

    public InvokeInstruction createInvoke(String className, String name, Type retType, Type[] argTypes, short kind)
    Create an invoke instruction. (Except for invokedynamic.)
    Parameters:
      `className` - name of the called class
      `name` - name of the called method
      `retType` - return type of method
      `argTypes` - argument types of method
      `kind` - how to invoke, i.e., INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL, or INVOKESPECIAL
    See Also:
      - `Const`

  - ### createInvoke

    public InvokeInstruction createInvoke(String className, String name, Type retType, Type[] argTypes, short kind, boolean useInterface)
    Create an invoke instruction. (Except for invokedynamic.)
    Parameters:
      `className` - name of the called class
      `name` - name of the called method
      `retType` - return type of method
      `argTypes` - argument types of method
      `kind` - how to invoke: INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL, or INVOKESPECIAL
      `useInterface` - force use of InterfaceMethodref
    Returns:
      A new InvokeInstruction.
    Since:
      6.5.0

  - ### createNew

    public NEW createNew(ObjectType t)

  - ### createNew

    public NEW createNew(String s)

  - ### createNewArray

    public Instruction createNewArray(Type t, short dim)
    Create new array of given size and type.
    Returns:
      an instruction that creates the corresponding array at runtime, i.e. is an AllocationInstruction

  - ### createPrintln

    public InstructionList createPrintln(String s)
    Create a call to the most popular System.out.println() method.
    Parameters:
      `s` - the string to print

  - ### createPutField

    public PUTFIELD createPutField(String className, String name, Type t)

  - ### createPutStatic

    public PUTSTATIC createPutStatic(String className, String name, Type t)

  - ### getClassGen

    public ClassGen getClassGen()

  - ### getConstantPool

    public ConstantPoolGen getConstantPool()

  - ### setClassGen

    public void setClassGen(ClassGen c)

  - ### setConstantPool

    public void setConstantPool(ConstantPoolGen c)