class MethodWriter extends MethodVisitor
MethodVisitor
that generates methods in bytecode form. Each visit
method of this class appends the bytecode corresponding to the visited
instruction to a byte vector, in the order these methods are called.Modifier and Type | Field and Description |
---|---|
(package private) static int |
ACC_CONSTRUCTOR
Pseudo access flag used to denote constructors.
|
(package private) static int |
APPEND_FRAME
Frame where current locals are the same as the locals in the previous
frame, except that k additional locals are defined.
|
(package private) static int |
CHOP_FRAME
Frame where current locals are the same as the locals in the previous
frame, except that the k last locals are absent.
|
(package private) int |
classReaderLength
If not zero, indicates that the code of this method must be copied from
the ClassReader associated to this writer in
cw.cr . |
(package private) int |
classReaderOffset
If not zero, indicates that the code of this method must be copied from
the ClassReader associated to this writer in
cw.cr . |
(package private) ClassWriter |
cw
The class writer to which this method must be added.
|
(package private) int |
exceptionCount
Number of exceptions that can be thrown by this method.
|
(package private) int[] |
exceptions
The exceptions that can be thrown by this method.
|
(package private) static int |
FULL_FRAME
Full frame
|
(package private) static int |
RESERVED
Reserved for future use
|
(package private) static int |
SAME_FRAME
Frame has exactly the same locals as the previous stack map frame and
number of stack items is zero.
|
(package private) static int |
SAME_FRAME_EXTENDED
Frame has exactly the same locals as the previous stack map frame and
number of stack items is zero.
|
(package private) static int |
SAME_LOCALS_1_STACK_ITEM_FRAME
Frame has exactly the same locals as the previous stack map frame and
number of stack items is 1
|
(package private) static int |
SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED
Frame has exactly the same locals as the previous stack map frame and
number of stack items is 1.
|
(package private) java.lang.String |
signature
The signature of this method.
|
api, mv
Constructor and Description |
---|
MethodWriter(ClassWriter cw,
int access,
java.lang.String name,
java.lang.String desc,
java.lang.String signature,
java.lang.String[] exceptions,
boolean computeMaxs,
boolean computeFrames)
Constructs a new
MethodWriter . |
Modifier and Type | Method and Description |
---|---|
(package private) static int |
getNewOffset(int[] indexes,
int[] sizes,
int begin,
int end)
Computes the future value of a bytecode offset.
|
(package private) static void |
getNewOffset(int[] indexes,
int[] sizes,
Label label)
Updates the offset of the given label.
|
(package private) int |
getSize()
Returns the size of the bytecode of this method.
|
(package private) void |
put(ByteVector out)
Puts the bytecode of this method in the given byte vector.
|
(package private) static int |
readInt(byte[] b,
int index)
Reads a signed int value in the given byte array.
|
(package private) static short |
readShort(byte[] b,
int index)
Reads a signed short value in the given byte array.
|
(package private) static int |
readUnsignedShort(byte[] b,
int index)
Reads an unsigned short value in the given byte array.
|
AnnotationVisitor |
visitAnnotation(java.lang.String desc,
boolean visible)
Visits an annotation of this method.
|
AnnotationVisitor |
visitAnnotationDefault()
Visits the default value of this annotation interface method.
|
void |
visitAttribute(Attribute attr)
Visits a non standard attribute of this method.
|
void |
visitCode()
Starts the visit of the method's code, if any (i.e.
|
void |
visitEnd()
Visits the end of the method.
|
void |
visitFieldInsn(int opcode,
java.lang.String owner,
java.lang.String name,
java.lang.String desc)
Visits a field instruction.
|
void |
visitFrame(int type,
int nLocal,
java.lang.Object[] local,
int nStack,
java.lang.Object[] stack)
Visits the current state of the local variables and operand stack
elements.
|
void |
visitIincInsn(int var,
int increment)
Visits an IINC instruction.
|
void |
visitInsn(int opcode)
Visits a zero operand instruction.
|
void |
visitIntInsn(int opcode,
int operand)
Visits an instruction with a single int operand.
|
void |
visitInvokeDynamicInsn(java.lang.String name,
java.lang.String desc,
Handle bsm,
java.lang.Object... bsmArgs)
Visits an invokedynamic instruction.
|
void |
visitJumpInsn(int opcode,
Label label)
Visits a jump instruction.
|
void |
visitLabel(Label label)
Visits a label.
|
void |
visitLdcInsn(java.lang.Object cst)
Visits a LDC instruction.
|
void |
visitLineNumber(int line,
Label start)
Visits a line number declaration.
|
void |
visitLocalVariable(java.lang.String name,
java.lang.String desc,
java.lang.String signature,
Label start,
Label end,
int index)
Visits a local variable declaration.
|
void |
visitLookupSwitchInsn(Label dflt,
int[] keys,
Label[] labels)
Visits a LOOKUPSWITCH instruction.
|
void |
visitMaxs(int maxStack,
int maxLocals)
Visits the maximum stack size and the maximum number of local variables
of the method.
|
void |
visitMethodInsn(int opcode,
java.lang.String owner,
java.lang.String name,
java.lang.String desc)
Visits a method instruction.
|
void |
visitMultiANewArrayInsn(java.lang.String desc,
int dims)
Visits a MULTIANEWARRAY instruction.
|
AnnotationVisitor |
visitParameterAnnotation(int parameter,
java.lang.String desc,
boolean visible)
Visits an annotation of a parameter this method.
|
void |
visitTableSwitchInsn(int min,
int max,
Label dflt,
Label... labels)
Visits a TABLESWITCH instruction.
|
void |
visitTryCatchBlock(Label start,
Label end,
Label handler,
java.lang.String type)
Visits a try catch block.
|
void |
visitTypeInsn(int opcode,
java.lang.String type)
Visits a type instruction.
|
void |
visitVarInsn(int opcode,
int var)
Visits a local variable instruction.
|
(package private) static void |
writeShort(byte[] b,
int index,
int s)
Writes a short value in the given byte array.
|
static final int ACC_CONSTRUCTOR
static final int SAME_FRAME
static final int SAME_LOCALS_1_STACK_ITEM_FRAME
static final int RESERVED
static final int SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED
static final int CHOP_FRAME
static final int SAME_FRAME_EXTENDED
static final int APPEND_FRAME
static final int FULL_FRAME
final ClassWriter cw
java.lang.String signature
int classReaderOffset
cw.cr
. More
precisely, this field gives the index of the first byte to copied from
cw.cr.b
.int classReaderLength
cw.cr
. More
precisely, this field gives the number of bytes to copied from
cw.cr.b
.int exceptionCount
int[] exceptions
MethodWriter(ClassWriter cw, int access, java.lang.String name, java.lang.String desc, java.lang.String signature, java.lang.String[] exceptions, boolean computeMaxs, boolean computeFrames)
MethodWriter
.cw
- the class writer in which the method must be added.access
- the method's access flags (see Opcodes
).name
- the method's name.desc
- the method's descriptor (see Type
).signature
- the method's signature. May be null.exceptions
- the internal names of the method's exceptions. May be
null.computeMaxs
- true if the maximum stack size and number
of local variables must be automatically computed.computeFrames
- true if the stack map tables must be
recomputed from scratch.public AnnotationVisitor visitAnnotationDefault()
MethodVisitor
visitAnnotationDefault
in class MethodVisitor
public AnnotationVisitor visitAnnotation(java.lang.String desc, boolean visible)
MethodVisitor
visitAnnotation
in class MethodVisitor
desc
- the class descriptor of the annotation class.visible
- true if the annotation is visible at runtime.public AnnotationVisitor visitParameterAnnotation(int parameter, java.lang.String desc, boolean visible)
MethodVisitor
visitParameterAnnotation
in class MethodVisitor
parameter
- the parameter index.desc
- the class descriptor of the annotation class.visible
- true if the annotation is visible at runtime.public void visitAttribute(Attribute attr)
MethodVisitor
visitAttribute
in class MethodVisitor
attr
- an attribute.public void visitCode()
MethodVisitor
visitCode
in class MethodVisitor
public void visitFrame(int type, int nLocal, java.lang.Object[] local, int nStack, java.lang.Object[] stack)
MethodVisitor
V1_6
. Opcodes.F_SAME
representing frame with exactly the same
locals as the previous frame and with the empty stack.Opcodes.F_SAME1
representing frame with exactly the same locals as the previous frame and
with single value on the stack (nStack
is 1 and
stack[0]
contains value for the type of the stack item).Opcodes.F_APPEND
representing frame with current locals are
the same as the locals in the previous frame, except that additional
locals are defined (nLocal
is 1, 2 or 3 and
local
elements contains values representing added types).Opcodes.F_CHOP
representing frame with current locals are
the same as the locals in the previous frame, except that the last 1-3
locals are absent and with the empty stack (nLocals
is 1,
2 or 3). Opcodes.F_FULL
representing complete frame
data.visitFrame
in class MethodVisitor
type
- the type of this stack map frame. Must be
Opcodes.F_NEW
for expanded frames, or
Opcodes.F_FULL
, Opcodes.F_APPEND
,
Opcodes.F_CHOP
, Opcodes.F_SAME
or
Opcodes.F_APPEND
, Opcodes.F_SAME1
for compressed
frames.nLocal
- the number of local variables in the visited frame.local
- the local variable types in this frame. This array must not
be modified. Primitive types are represented by
Opcodes.TOP
, Opcodes.INTEGER
,
Opcodes.FLOAT
, Opcodes.LONG
,
Opcodes.DOUBLE
,Opcodes.NULL
or
Opcodes.UNINITIALIZED_THIS
(long and double are
represented by a single element). Reference types are represented
by String objects (representing internal names), and uninitialized
types by Label objects (this label designates the NEW instruction
that created this uninitialized value).nStack
- the number of operand stack elements in the visited frame.stack
- the operand stack types in this frame. This array must not
be modified. Its content has the same format as the "local" array.public void visitInsn(int opcode)
MethodVisitor
visitInsn
in class MethodVisitor
opcode
- the opcode of the instruction to be visited. This opcode is
either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2,
ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0,
FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD,
DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE,
DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP,
DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD,
DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV,
FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL,
LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR,
I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B,
I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN,
FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW,
MONITORENTER, or MONITOREXIT.public void visitIntInsn(int opcode, int operand)
MethodVisitor
visitIntInsn
in class MethodVisitor
opcode
- the opcode of the instruction to be visited. This opcode is
either BIPUSH, SIPUSH or NEWARRAY.operand
- the operand of the instruction to be visited.Opcodes.T_BOOLEAN
, Opcodes.T_CHAR
,
Opcodes.T_FLOAT
, Opcodes.T_DOUBLE
,
Opcodes.T_BYTE
, Opcodes.T_SHORT
,
Opcodes.T_INT
or Opcodes.T_LONG
.public void visitVarInsn(int opcode, int var)
MethodVisitor
visitVarInsn
in class MethodVisitor
opcode
- the opcode of the local variable instruction to be visited.
This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE,
LSTORE, FSTORE, DSTORE, ASTORE or RET.var
- the operand of the instruction to be visited. This operand is
the index of a local variable.public void visitTypeInsn(int opcode, java.lang.String type)
MethodVisitor
visitTypeInsn
in class MethodVisitor
opcode
- the opcode of the type instruction to be visited. This
opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.type
- the operand of the instruction to be visited. This operand
must be the internal name of an object or array class (see getInternalName
).public void visitFieldInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc)
MethodVisitor
visitFieldInsn
in class MethodVisitor
opcode
- the opcode of the type instruction to be visited. This
opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.owner
- the internal name of the field's owner class (see getInternalName
).name
- the field's name.desc
- the field's descriptor (see Type
).public void visitMethodInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc)
MethodVisitor
visitMethodInsn
in class MethodVisitor
opcode
- the opcode of the type instruction to be visited. This
opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC
or INVOKEINTERFACE.owner
- the internal name of the method's owner class (see getInternalName
).name
- the method's name.desc
- the method's descriptor (see Type
).public void visitInvokeDynamicInsn(java.lang.String name, java.lang.String desc, Handle bsm, java.lang.Object... bsmArgs)
MethodVisitor
visitInvokeDynamicInsn
in class MethodVisitor
name
- the method's name.desc
- the method's descriptor (see Type
).bsm
- the bootstrap method.bsmArgs
- the bootstrap method constant arguments. Each argument
must be an Integer
, Float
, Long
,
Double
, String
, Type
or Handle
value. This method is allowed to modify the content of the array
so a caller should expect that this array may change.public void visitJumpInsn(int opcode, Label label)
MethodVisitor
visitJumpInsn
in class MethodVisitor
opcode
- the opcode of the type instruction to be visited. This
opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ,
IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.label
- the operand of the instruction to be visited. This operand
is a label that designates the instruction to which the jump
instruction may jump.public void visitLabel(Label label)
MethodVisitor
visitLabel
in class MethodVisitor
label
- a Label
object.public void visitLdcInsn(java.lang.Object cst)
MethodVisitor
if (cst instanceof Integer) { // ... } else if (cst instanceof Float) { // ... } else if (cst instanceof Long) { // ... } else if (cst instanceof Double) { // ... } else if (cst instanceof String) { // ... } else if (cst instanceof Type) { int sort = ((Type) cst).getSort(); if (sort == Type.OBJECT) { // ... } else if (sort == Type.ARRAY) { // ... } else if (sort == Type.METHOD) { // ... } else { // throw an exception } } else if (cst instanceof Handle) { // ... } else { // throw an exception }
visitLdcInsn
in class MethodVisitor
cst
- the constant to be loaded on the stack. This parameter must be
a non null Integer
, a Float
, a Long
, a
Double
, a String
, a Type
of OBJECT or ARRAY
sort for .class constants, for classes whose version is
49.0, a Type
of METHOD sort or a Handle
for
MethodType and MethodHandle constants, for classes whose version
is 51.0.public void visitIincInsn(int var, int increment)
MethodVisitor
visitIincInsn
in class MethodVisitor
var
- index of the local variable to be incremented.increment
- amount to increment the local variable by.public void visitTableSwitchInsn(int min, int max, Label dflt, Label... labels)
MethodVisitor
visitTableSwitchInsn
in class MethodVisitor
min
- the minimum key value.max
- the maximum key value.dflt
- beginning of the default handler block.labels
- beginnings of the handler blocks. labels[i] is
the beginning of the handler block for the min + i key.public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels)
MethodVisitor
visitLookupSwitchInsn
in class MethodVisitor
dflt
- beginning of the default handler block.keys
- the values of the keys.labels
- beginnings of the handler blocks. labels[i] is
the beginning of the handler block for the keys[i] key.public void visitMultiANewArrayInsn(java.lang.String desc, int dims)
MethodVisitor
visitMultiANewArrayInsn
in class MethodVisitor
desc
- an array type descriptor (see Type
).dims
- number of dimensions of the array to allocate.public void visitTryCatchBlock(Label start, Label end, Label handler, java.lang.String type)
MethodVisitor
visitTryCatchBlock
in class MethodVisitor
start
- beginning of the exception handler's scope (inclusive).end
- end of the exception handler's scope (exclusive).handler
- beginning of the exception handler's code.type
- internal name of the type of exceptions handled by the
handler, or null to catch any exceptions (for "finally"
blocks).public void visitLocalVariable(java.lang.String name, java.lang.String desc, java.lang.String signature, Label start, Label end, int index)
MethodVisitor
visitLocalVariable
in class MethodVisitor
name
- the name of a local variable.desc
- the type descriptor of this local variable.signature
- the type signature of this local variable. May be
null if the local variable type does not use generic
types.start
- the first instruction corresponding to the scope of this
local variable (inclusive).end
- the last instruction corresponding to the scope of this local
variable (exclusive).index
- the local variable's index.public void visitLineNumber(int line, Label start)
MethodVisitor
visitLineNumber
in class MethodVisitor
line
- a line number. This number refers to the source file from
which the class was compiled.start
- the first instruction corresponding to this line number.public void visitMaxs(int maxStack, int maxLocals)
MethodVisitor
visitMaxs
in class MethodVisitor
maxStack
- maximum stack size of the method.maxLocals
- maximum number of local variables for the method.public void visitEnd()
MethodVisitor
visitEnd
in class MethodVisitor
final int getSize()
final void put(ByteVector out)
out
- the byte vector into which the bytecode of this method must be
copied.static int readUnsignedShort(byte[] b, int index)
b
- a byte array.index
- the start index of the value to be read.static short readShort(byte[] b, int index)
b
- a byte array.index
- the start index of the value to be read.static int readInt(byte[] b, int index)
b
- a byte array.index
- the start index of the value to be read.static void writeShort(byte[] b, int index, int s)
b
- a byte array.index
- where the first byte of the short value must be written.s
- the value to be written in the given byte array.static int getNewOffset(int[] indexes, int[] sizes, int begin, int end)
Note: it is possible to have several entries for the same instruction in the indexes and sizes: two entries (index=a,size=b) and (index=a,size=b') are equivalent to a single entry (index=a,size=b+b').
indexes
- current positions of the instructions to be resized. Each
instruction must be designated by the index of its last
byte, plus one (or, in other words, by the index of the first
byte of the next instruction).sizes
- the number of bytes to be added to the above
instructions. More precisely, for each i < len,
sizes[i] bytes will be added at the end of the
instruction designated by indexes[i] or, if
sizes[i] is negative, the last |sizes[i]|
bytes of the instruction will be removed (the instruction size
must not become negative or null).begin
- index of the first byte of the source instruction.end
- index of the first byte of the target instruction.static void getNewOffset(int[] indexes, int[] sizes, Label label)
indexes
- current positions of the instructions to be resized. Each
instruction must be designated by the index of its last
byte, plus one (or, in other words, by the index of the first
byte of the next instruction).sizes
- the number of bytes to be added to the above
instructions. More precisely, for each i < len,
sizes[i] bytes will be added at the end of the
instruction designated by indexes[i] or, if
sizes[i] is negative, the last |sizes[i]|
bytes of the instruction will be removed (the instruction size
must not become negative or null).label
- the label whose offset must be updated.Copyright (c) 2004-2012 Oracle. All rights reserved.