fr.umlv.corosol.classfile.bytecode.impl
Class DefaultJBytecodeParser

java.lang.Object
  fr.umlv.corosol.classfile.bytecode.impl.DefaultJBytecodeParser

All Implemented Interfaces:

JBytecodeParser

public class DefaultJBytecodeParser
extends java.lang.Object
implements JBytecodeParser

The default implementation of the bytecode parser JBytecodeParser.

Author:

Christophe Deleray

Field Summary

Fields inherited from interface fr.umlv.corosol.classfile.bytecode.JBytecodeParser

AALOAD, AASTORE, ACONST_NULL, ALOAD, ALOAD_0, ALOAD_1, ALOAD_2, ALOAD_3, ANEWARRAY, ARETURN, ARRAYLENGTH, ASTORE, ASTORE_0, ASTORE_1, ASTORE_2, ASTORE_3, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DLOAD_0, DLOAD_1, DLOAD_2, DLOAD_3, DMUL, DNEG, DREM, DRETURN, DSTORE, DSTORE_0, DSTORE_1, DSTORE_2, DSTORE_3, 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, FLOAD, FLOAD_0, FLOAD_1, FLOAD_2, FLOAD_3, FMUL, FNEG, FREM, FRETURN, FSTORE, FSTORE_0, FSTORE_1, FSTORE_2, FSTORE_3, FSUB, GETFIELD, GETSTATIC, GOTO, GOTO_W, 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, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, ILOAD_0, ILOAD_1, ILOAD_2, ILOAD_3, IMUL, INEG, INSTANCEOF, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISTORE_0, ISTORE_1, ISTORE_2, ISTORE_3, ISUB, IUSHR, IXOR, JSR, JSR_W, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDC_W, LDC2_W, LDIV, LLOAD, LLOAD_0, LLOAD_1, LLOAD_2, LLOAD_3, LMUL, LNEG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSTORE_0, LSTORE_1, LSTORE_2, LSTORE_3, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, TABLESWITCH, WIDE

Constructor Summary

DefaultJBytecodeParser()
Creates a new bytecode parser not initialized with a bytecode array.

Method Summary

void	fillInput(byte[] b, int off, int len) Resets the bytecode parsing and initializes it with the len bytes of the specified bytes array, starting at the off position.
java.lang.String	getMnemonic() Returns the mnemonic of the next instruction opcode read from this bytecode parser.
int	getOpcodeCount() Calculates the number of times that this bytecode parser's nextOpcode method can be called before it generates an exception.
int	getOperandCount() Returns the number of operands of the current instruction read with the nextOpcode method.
int	getPosition() Returns the current opcode position in the bytecodes flow.
boolean	hasMoreOpcode() Tests if there are more instruction opcode available from this bytecode parser.
int	nextOpcode() Returns the next instruction opcode from this bytecode parser.
int	readOperands(byte[] b, int off, int len) Reads up to len operand of the current instruction, read with the nextOpcode method, into an array of bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultJBytecodeParser

public DefaultJBytecodeParser()

Creates a new bytecode parser not initialized with a bytecode array.

Method Detail

hasMoreOpcode

public boolean hasMoreOpcode()

Tests if there are more instruction opcode available from this bytecode parser. If this method returns true, then a subsequent call to nextOpcode with no argument will successfully return an instruction opcode.

Specified by:

hasMoreOpcode in interface JBytecodeParser

Returns:

true if and only if there is at least one opcode in the bytecode after the current position; false otherwise.

nextOpcode

public int nextOpcode()

Returns the next instruction opcode from this bytecode parser. If this instruction has operands, they can be read with the readOperands method.

Specified by:

nextOpcode in interface JBytecodeParser

Returns:

the next instruction opcode from this bytecode parser

Throws:

java.util.NoSuchElementException - if there are no more instruction opcode in this bytecode parser

See Also:

readOperands(byte[], int, int)

getMnemonic

public java.lang.String getMnemonic()

Returns the mnemonic of the next instruction opcode read from this bytecode parser. This instructions does not change the instruction opcodes flow.

Specified by:

getMnemonic in interface JBytecodeParser

Returns:

the mnemonic of the instruction opcode read from this bytecode parser

getPosition

public int getPosition()

Returns the current opcode position in the bytecodes flow.

Specified by:

getPosition in interface JBytecodeParser

readOperands

public int readOperands(byte[] b,
                        int off,
                        int len)

Reads up to len operand of the current instruction, read with the nextOpcode method, into an array of bytes. An attempt is made to read as many as len operand bytes, but a smaller number may be read, possibly zero if the current instruction is without operand. The number of operands actually read is returned as an integer.

Specified by:

readOperands in interface JBytecodeParser

Parameters:

b - the buffer into which the operands are read.

off - the start offset in array b at which the operands are written

len - the maximum number of operands to read

Returns:

the total number of bytes read into the buffer, or

getOpcodeCount

public int getOpcodeCount()

Calculates the number of times that this bytecode parser's nextOpcode method can be called before it generates an exception. The current position is not advanced.

Specified by:

getOpcodeCount in interface JBytecodeParser

Returns:

the number of instructions opcode remaining in the bytecode

getOperandCount

public int getOperandCount()

Returns the number of operands of the current instruction read with the nextOpcode method.

Specified by:

getOperandCount in interface JBytecodeParser

Returns:

the number of operands of the current instruction or -1 if there

fillInput

public void fillInput(byte[] b,
                      int off,
                      int len)

Resets the bytecode parsing and initializes it with the len bytes of the specified bytes array, starting at the off position.

Specified by:

fillInput in interface JBytecodeParser

Parameters:

b - the bytecode of a method

off - the start offset in array b at which the parsing is processed

len - the maximum number of bytes to analyse