MethodWriter

java.lang.Object
- org.springframework.asm.MethodVisitor
- - org.springframework.asm.MethodWriter

```
 class MethodWriter
extends MethodVisitor
```
A 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.

Author:

Eric Bruneton, Eugene Kuleshov

Field Summary

Fields
Modifier and Type	Field and Description
`(package private) static int`	`ACC_CONSTRUCTOR` Pseudo access flag used to denote constructors.
`private int`	`access` Access flags of this method.
`private ByteVector`	`annd` The annotation default attribute of this method.
`private AnnotationWriter`	`anns` The runtime visible annotations of this method.
`(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.
`private Attribute`	`attrs` The non standard attributes of the method.
`private Attribute`	`cattrs` The non standard attributes of the method's code.
`(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`.
`private ByteVector`	`code` The bytecode of this method.
`private int`	`compute` Indicates what must be automatically computed.
`private Label`	`currentBlock` The current basic block.
`private int`	`currentLocals` Number of local variables in the current stack map frame.
`(package private) ClassWriter`	`cw` The class writer to which this method must be added.
`private int`	`desc` The index of the constant pool item that contains the descriptor of this method.
`private java.lang.String`	`descriptor` The descriptor of this method.
`(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.
`private Handler`	`firstHandler` The first element in the exception handler list.
`private int[]`	`frame` The current stack map frame.
`private int`	`frameCount` Number of stack map frames in the StackMapTable attribute.
`private static int`	`FRAMES` Indicates that the stack map frames must be recomputed from scratch.
`(package private) static int`	`FULL_FRAME` Full frame
`private int`	`handlerCount` Number of elements in the exception handler list.
`private AnnotationWriter`	`ianns` The runtime invisible annotations of this method.
`private AnnotationWriter[]`	`ipanns` The runtime invisible parameter annotations of this method.
`private Label`	`labels` A list of labels.
`private Handler`	`lastHandler` The last element in the exception handler list.
`private ByteVector`	`lineNumber` The LineNumberTable attribute.
`private int`	`lineNumberCount` Number of entries in the LineNumberTable attribute.
`private ByteVector`	`localVar` The LocalVariableTable attribute.
`private int`	`localVarCount` Number of entries in the LocalVariableTable attribute.
`private ByteVector`	`localVarType` The LocalVariableTypeTable attribute.
`private int`	`localVarTypeCount` Number of entries in the LocalVariableTypeTable attribute.
`private int`	`maxLocals` Maximum number of local variables for this method.
`private static int`	`MAXS` Indicates that the maximum stack size and number of local variables must be automatically computed.
`private int`	`maxStack` Maximum stack size of this method.
`private int`	`maxStackSize` The (relative) maximum stack size after the last visited instruction.
`private int`	`name` The index of the constant pool item that contains the name of this method.
`private static int`	`NOTHING` Indicates that nothing must be automatically computed.
`private AnnotationWriter[]`	`panns` The runtime visible parameter annotations of this method.
`private Label`	`previousBlock` The previous basic block.
`private int[]`	`previousFrame` The last frame that was written in the StackMapTable attribute.
`private int`	`previousFrameOffset` The offset of the last frame that was written in the StackMapTable attribute.
`(package private) static int`	`RESERVED` Reserved for future use
`private boolean`	`resize` Indicates if some jump instructions are too small and need to be resized.
`(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.
`private ByteVector`	`stackMap` The StackMapTable attribute.
`private int`	`stackSize` The (relative) stack size after the last visited instruction.
`private int`	`subroutines` The number of subroutines in this method.
`private int`	`synthetics` The number of synthetic parameters of this method.

Fields inherited from class org.springframework.asm.MethodVisitor
api, mv

Constructor Summary

Constructors
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`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private void`	`addSuccessor(int info, Label successor)` Adds a successor to the `currentBlock` block.
`private void`	`endFrame()` Checks if the visit of the current frame `frame` is finished, and if yes, write it in the StackMapTable attribute.
`(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.
`private void`	`noSuccessor()` Ends the current basic block.
`(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.
`private void`	`resizeInstructions()` Resizes and replaces the temporary instructions inserted by `Label.resolve(org.springframework.asm.MethodWriter, int, byte[])` for wide forward jumps, while keeping jump offsets and instruction addresses consistent.
`private int`	`startFrame(int offset, int nLocal, int nStack)` Starts the visit of a stack map frame.
`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.
`private void`	`visitFrame(Frame f)` Visits a frame that has been computed from scratch.
`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.
`private void`	`visitImplicitFirstFrame()` Visit the implicit first frame of this method.
`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.
`private void`	`visitSwitchInsn(Label dflt, Label[] labels)`
`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.
`private void`	`writeFrame()` Compress and writes the current frame `frame` in the StackMapTable attribute.
`private void`	`writeFrameType(java.lang.Object type)`
`private void`	`writeFrameTypes(int start, int end)` Writes some types of the current frame `frame` into the StackMapTableAttribute.
`(package private) static void`	`writeShort(byte[] b, int index, int s)` Writes a short value in the given byte array.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ACC_CONSTRUCTOR
```
static final int ACC_CONSTRUCTOR
```
    Pseudo access flag used to denote constructors.
    
    See Also:
    Constant Field Values
  - SAME_FRAME
```
static final int SAME_FRAME
```
    Frame has exactly the same locals as the previous stack map frame and number of stack items is zero.
    
    See Also:
    Constant Field Values
  - SAME_LOCALS_1_STACK_ITEM_FRAME
```
static final 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
    
    See Also:
    Constant Field Values
  - RESERVED
```
static final int RESERVED
```
    Reserved for future use
    
    See Also:
    Constant Field Values
  - SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED
```
static final 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. Offset is bigger then 63;
    
    See Also:
    Constant Field Values
  - CHOP_FRAME
```
static final 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. The value of k is given by the formula 251-frame_type.
    
    See Also:
    Constant Field Values
  - SAME_FRAME_EXTENDED
```
static final int SAME_FRAME_EXTENDED
```
    Frame has exactly the same locals as the previous stack map frame and number of stack items is zero. Offset is bigger then 63;
    
    See Also:
    Constant Field Values
  - APPEND_FRAME
```
static final int APPEND_FRAME
```
    Frame where current locals are the same as the locals in the previous frame, except that k additional locals are defined. The value of k is given by the formula frame_type-251.
    
    See Also:
    Constant Field Values
  - FULL_FRAME
```
static final int FULL_FRAME
```
    Full frame
    
    See Also:
    Constant Field Values
  - FRAMES
```
private static final int FRAMES
```
    Indicates that the stack map frames must be recomputed from scratch. In this case the maximum stack size and number of local variables is also recomputed from scratch.
    
    See Also:
    compute, Constant Field Values
  - MAXS
```
private static final int MAXS
```
    Indicates that the maximum stack size and number of local variables must be automatically computed.
    
    See Also:
    compute, Constant Field Values
  - NOTHING
```
private static final int NOTHING
```
    Indicates that nothing must be automatically computed.
    
    See Also:
    compute, Constant Field Values
  - cw
```
final ClassWriter cw
```
    The class writer to which this method must be added.
  - access
```
private int access
```
    Access flags of this method.
  - name
```
private final int name
```
    The index of the constant pool item that contains the name of this method.
  - desc
```
private final int desc
```
    The index of the constant pool item that contains the descriptor of this method.
  - descriptor
```
private final java.lang.String descriptor
```
    The descriptor of this method.
  - signature
```
java.lang.String signature
```
    The signature of this method.
  - classReaderOffset
```
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. More precisely, this field gives the index of the first byte to copied from cw.cr.b.
  - classReaderLength
```
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. More precisely, this field gives the number of bytes to copied from cw.cr.b.
  - exceptionCount
```
int exceptionCount
```
    Number of exceptions that can be thrown by this method.
  - exceptions
```
int[] exceptions
```
    The exceptions that can be thrown by this method. More precisely, this array contains the indexes of the constant pool items that contain the internal names of these exception classes.
  - annd
```
private ByteVector annd
```
    The annotation default attribute of this method. May be null.
  - anns
```
private AnnotationWriter anns
```
    The runtime visible annotations of this method. May be null.
  - ianns
```
private AnnotationWriter ianns
```
    The runtime invisible annotations of this method. May be null.
  - panns
```
private AnnotationWriter[] panns
```
    The runtime visible parameter annotations of this method. May be null.
  - ipanns
```
private AnnotationWriter[] ipanns
```
    The runtime invisible parameter annotations of this method. May be null.
  - synthetics
```
private int synthetics
```
    The number of synthetic parameters of this method.
  - attrs
```
private Attribute attrs
```
    The non standard attributes of the method.
  - code
```
private ByteVector code
```
    The bytecode of this method.
  - maxStack
```
private int maxStack
```
    Maximum stack size of this method.
  - maxLocals
```
private int maxLocals
```
    Maximum number of local variables for this method.
  - currentLocals
```
private int currentLocals
```
    Number of local variables in the current stack map frame.
  - frameCount
```
private int frameCount
```
    Number of stack map frames in the StackMapTable attribute.
  - stackMap
```
private ByteVector stackMap
```
    The StackMapTable attribute.
  - previousFrameOffset
```
private int previousFrameOffset
```
    The offset of the last frame that was written in the StackMapTable attribute.
  - previousFrame
```
private int[] previousFrame
```
    The last frame that was written in the StackMapTable attribute.
    
    See Also:
    frame
  - frame
```
private int[] frame
```
    The current stack map frame. The first element contains the offset of the instruction to which the frame corresponds, the second element is the number of locals and the third one is the number of stack elements. The local variables start at index 3 and are followed by the operand stack values. In summary frame[0] = offset, frame[1] = nLocal, frame[2] = nStack, frame[3] = nLocal. All types are encoded as integers, with the same format as the one used in Label, but limited to BASE types.
  - handlerCount
```
private int handlerCount
```
    Number of elements in the exception handler list.
  - firstHandler
```
private Handler firstHandler
```
    The first element in the exception handler list.
  - lastHandler
```
private Handler lastHandler
```
    The last element in the exception handler list.
  - localVarCount
```
private int localVarCount
```
    Number of entries in the LocalVariableTable attribute.
  - localVar
```
private ByteVector localVar
```
    The LocalVariableTable attribute.
  - localVarTypeCount
```
private int localVarTypeCount
```
    Number of entries in the LocalVariableTypeTable attribute.
  - localVarType
```
private ByteVector localVarType
```
    The LocalVariableTypeTable attribute.
  - lineNumberCount
```
private int lineNumberCount
```
    Number of entries in the LineNumberTable attribute.
  - lineNumber
```
private ByteVector lineNumber
```
    The LineNumberTable attribute.
  - cattrs
```
private Attribute cattrs
```
    The non standard attributes of the method's code.
  - resize
```
private boolean resize
```
    Indicates if some jump instructions are too small and need to be resized.
  - subroutines
```
private int subroutines
```
    The number of subroutines in this method.
  - compute
```
private final int compute
```
    Indicates what must be automatically computed.
    
    See Also:
    FRAMES, MAXS, NOTHING
  - labels
```
private Label labels
```
    A list of labels. This list is the list of basic blocks in the method, i.e. a list of Label objects linked to each other by their Label.successor field, in the order they are visited by MethodVisitor.visitLabel(org.springframework.asm.Label), and starting with the first basic block.
  - previousBlock
```
private Label previousBlock
```
    The previous basic block.
  - currentBlock
```
private Label currentBlock
```
    The current basic block.
  - stackSize
```
private int stackSize
```
    The (relative) stack size after the last visited instruction. This size is relative to the beginning of the current basic block, i.e., the true stack size after the last visited instruction is equal to the beginStackSize of the current basic block plus stackSize.
  - maxStackSize
```
private int maxStackSize
```
    The (relative) maximum stack size after the last visited instruction. This size is relative to the beginning of the current basic block, i.e., the true maximum stack size after the last visited instruction is equal to the beginStackSize of the current basic block plus stackSize.
- Constructor Detail
  - MethodWriter
```
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.
    
    Parameters:
    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.
- Method Detail
  - visitAnnotationDefault
```
public AnnotationVisitor visitAnnotationDefault()
```
    Description copied from class: MethodVisitor
    
    Visits the default value of this annotation interface method.
    
    Overrides:
    
    visitAnnotationDefault in class MethodVisitor
    
    Returns:
    a visitor to the visit the actual default value of this annotation interface method, or null if this visitor is not interested in visiting this default value. The 'name' parameters passed to the methods of this annotation visitor are ignored. Moreover, exacly one visit method must be called on this annotation visitor, followed by visitEnd.
  - visitAnnotation
```
public AnnotationVisitor visitAnnotation(java.lang.String desc,
                                boolean visible)
```
    Description copied from class: MethodVisitor
    
    Visits an annotation of this method.
    
    Overrides:
    
    visitAnnotation in class MethodVisitor
    
    Parameters:
    desc - the class descriptor of the annotation class.
    visible - true if the annotation is visible at runtime.
    
    Returns:
    a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
  - visitParameterAnnotation
```
public AnnotationVisitor visitParameterAnnotation(int parameter,
                                         java.lang.String desc,
                                         boolean visible)
```
    Description copied from class: MethodVisitor
    
    Visits an annotation of a parameter this method.
    
    Overrides:
    
    visitParameterAnnotation in class MethodVisitor
    
    Parameters:
    parameter - the parameter index.
    desc - the class descriptor of the annotation class.
    visible - true if the annotation is visible at runtime.
    
    Returns:
    a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
  - visitAttribute
```
public void visitAttribute(Attribute attr)
```
    Description copied from class: MethodVisitor
    
    Visits a non standard attribute of this method.
    
    Overrides:
    
    visitAttribute in class MethodVisitor
    
    Parameters:
    attr - an attribute.
  - visitCode
```
public void visitCode()
```
    Description copied from class: MethodVisitor
    
    Starts the visit of the method's code, if any (i.e. non abstract method).
    
    Overrides:
    
    visitCode in class MethodVisitor
  - visitFrame
```
public void visitFrame(int type,
              int nLocal,
              java.lang.Object[] local,
              int nStack,
              java.lang.Object[] stack)
```
    Description copied from class: MethodVisitor
    Visits the current state of the local variables and operand stack elements. This method must(*) be called just before any instruction i that follows an unconditional branch instruction such as GOTO or THROW, that is the target of a jump instruction, or that starts an exception handler block. The visited types must describe the values of the local variables and of the operand stack elements just before i is executed.
    
    (*) this is mandatory only for classes whose version is greater than or equal to V1_6.
    
    The frames of a method must be given either in expanded form, or in compressed form (all frames must use the same format, i.e. you must not mix expanded and compressed frames within a single method):
    - In expanded form, all frames must have the F_NEW type.
    - In compressed form, frames are basically "deltas" from the state of the previous frame:
      
      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.
    In both cases the first frame, corresponding to the method's parameters and access flags, is implicit and must not be visited. Also, it is illegal to visit two or more frames for the same code location (i.e., at least one instruction must be visited between two calls to visitFrame).
    Overrides:
    
    visitFrame in class MethodVisitor
    
    Parameters:
    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.
  - visitInsn
```
public void visitInsn(int opcode)
```
    Description copied from class: MethodVisitor
    
    Visits a zero operand instruction.
    
    Overrides:
    
    visitInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitIntInsn
```
public void visitIntInsn(int opcode,
                int operand)
```
    Description copied from class: MethodVisitor
    
    Visits an instruction with a single int operand.
    
    Overrides:
    
    visitIntInsn in class MethodVisitor
    
    Parameters:
    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.
    When opcode is BIPUSH, operand value should be between Byte.MIN_VALUE and Byte.MAX_VALUE.
    When opcode is SIPUSH, operand value should be between Short.MIN_VALUE and Short.MAX_VALUE.
    When opcode is NEWARRAY, operand value should be one of 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.
  - visitVarInsn
```
public void visitVarInsn(int opcode,
                int var)
```
    Description copied from class: MethodVisitor
    
    Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.
    
    Overrides:
    
    visitVarInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitTypeInsn
```
public void visitTypeInsn(int opcode,
                 java.lang.String type)
```
    Description copied from class: MethodVisitor
    
    Visits a type instruction. A type instruction is an instruction that takes the internal name of a class as parameter.
    
    Overrides:
    
    visitTypeInsn in class MethodVisitor
    
    Parameters:
    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).
  - visitFieldInsn
```
public void visitFieldInsn(int opcode,
                  java.lang.String owner,
                  java.lang.String name,
                  java.lang.String desc)
```
    Description copied from class: MethodVisitor
    
    Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.
    
    Overrides:
    
    visitFieldInsn in class MethodVisitor
    
    Parameters:
    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).
  - visitMethodInsn
```
public void visitMethodInsn(int opcode,
                   java.lang.String owner,
                   java.lang.String name,
                   java.lang.String desc)
```
    Description copied from class: MethodVisitor
    
    Visits a method instruction. A method instruction is an instruction that invokes a method.
    
    Overrides:
    
    visitMethodInsn in class MethodVisitor
    
    Parameters:
    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).
  - visitInvokeDynamicInsn
```
public void visitInvokeDynamicInsn(java.lang.String name,
                          java.lang.String desc,
                          Handle bsm,
                          java.lang.Object... bsmArgs)
```
    Description copied from class: MethodVisitor
    
    Visits an invokedynamic instruction.
    
    Overrides:
    
    visitInvokeDynamicInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitJumpInsn
```
public void visitJumpInsn(int opcode,
                 Label label)
```
    Description copied from class: MethodVisitor
    
    Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.
    
    Overrides:
    
    visitJumpInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitLabel
```
public void visitLabel(Label label)
```
    Description copied from class: MethodVisitor
    
    Visits a label. A label designates the instruction that will be visited just after it.
    
    Overrides:
    
    visitLabel in class MethodVisitor
    
    Parameters:
    label - a Label object.
  - visitLdcInsn
```
public void visitLdcInsn(java.lang.Object cst)
```
    Description copied from class: MethodVisitor
    Visits a LDC instruction. Note that new constant types may be added in future versions of the Java Virtual Machine. To easily detect new constant types, implementations of this method should check for unexpected constant types, like this:
```
 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
 }
 
```
    Overrides:
    
    visitLdcInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitIincInsn
```
public void visitIincInsn(int var,
                 int increment)
```
    Description copied from class: MethodVisitor
    
    Visits an IINC instruction.
    
    Overrides:
    
    visitIincInsn in class MethodVisitor
    
    Parameters:
    var - index of the local variable to be incremented.
    increment - amount to increment the local variable by.
  - visitTableSwitchInsn
```
public void visitTableSwitchInsn(int min,
                        int max,
                        Label dflt,
                        Label... labels)
```
    Description copied from class: MethodVisitor
    
    Visits a TABLESWITCH instruction.
    
    Overrides:
    
    visitTableSwitchInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitLookupSwitchInsn
```
public void visitLookupSwitchInsn(Label dflt,
                         int[] keys,
                         Label[] labels)
```
    Description copied from class: MethodVisitor
    
    Visits a LOOKUPSWITCH instruction.
    
    Overrides:
    
    visitLookupSwitchInsn in class MethodVisitor
    
    Parameters:
    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.
  - visitSwitchInsn
```
private void visitSwitchInsn(Label dflt,
                   Label[] labels)
```
  - visitMultiANewArrayInsn
```
public void visitMultiANewArrayInsn(java.lang.String desc,
                           int dims)
```
    Description copied from class: MethodVisitor
    
    Visits a MULTIANEWARRAY instruction.
    
    Overrides:
    
    visitMultiANewArrayInsn in class MethodVisitor
    
    Parameters:
    desc - an array type descriptor (see Type).
    dims - number of dimensions of the array to allocate.
  - visitTryCatchBlock
```
public void visitTryCatchBlock(Label start,
                      Label end,
                      Label handler,
                      java.lang.String type)
```
    Description copied from class: MethodVisitor
    
    Visits a try catch block.
    
    Overrides:
    
    visitTryCatchBlock in class MethodVisitor
    
    Parameters:
    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).
  - visitLocalVariable
```
public void visitLocalVariable(java.lang.String name,
                      java.lang.String desc,
                      java.lang.String signature,
                      Label start,
                      Label end,
                      int index)
```
    Description copied from class: MethodVisitor
    
    Visits a local variable declaration.
    
    Overrides:
    
    visitLocalVariable in class MethodVisitor
    
    Parameters:
    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.
  - visitLineNumber
```
public void visitLineNumber(int line,
                   Label start)
```
    Description copied from class: MethodVisitor
    
    Visits a line number declaration.
    
    Overrides:
    
    visitLineNumber in class MethodVisitor
    
    Parameters:
    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.
  - visitMaxs
```
public void visitMaxs(int maxStack,
             int maxLocals)
```
    Description copied from class: MethodVisitor
    
    Visits the maximum stack size and the maximum number of local variables of the method.
    
    Overrides:
    
    visitMaxs in class MethodVisitor
    
    Parameters:
    maxStack - maximum stack size of the method.
    maxLocals - maximum number of local variables for the method.
  - visitEnd
```
public void visitEnd()
```
    Description copied from class: MethodVisitor
    
    Visits the end of the method. This method, which is the last one to be called, is used to inform the visitor that all the annotations and attributes of the method have been visited.
    
    Overrides:
    
    visitEnd in class MethodVisitor
  - addSuccessor
```
private void addSuccessor(int info,
                Label successor)
```
    Adds a successor to the currentBlock block.
    
    Parameters:
    info - information about the control flow edge to be added.
    successor - the successor block to be added to the current block.
  - noSuccessor
```
private void noSuccessor()
```
    Ends the current basic block. This method must be used in the case where the current basic block does not have any successor.
  - visitFrame
```
private void visitFrame(Frame f)
```
    Visits a frame that has been computed from scratch.
    
    Parameters:
    f - the frame that must be visited.
  - visitImplicitFirstFrame
```
private void visitImplicitFirstFrame()
```
    Visit the implicit first frame of this method.
  - startFrame
```
private int startFrame(int offset,
             int nLocal,
             int nStack)
```
    Starts the visit of a stack map frame.
    
    Parameters:
    offset - the offset of the instruction to which the frame corresponds.
    nLocal - the number of local variables in the frame.
    nStack - the number of stack elements in the frame.
    
    Returns:
    the index of the next element to be written in this frame.
  - endFrame
```
private void endFrame()
```
    Checks if the visit of the current frame frame is finished, and if yes, write it in the StackMapTable attribute.
  - writeFrame
```
private void writeFrame()
```
    Compress and writes the current frame frame in the StackMapTable attribute.
  - writeFrameTypes
```
private void writeFrameTypes(int start,
                   int end)
```
    Writes some types of the current frame frame into the StackMapTableAttribute. This method converts types from the format used in Label to the format used in StackMapTable attributes. In particular, it converts type table indexes to constant pool indexes.
    
    Parameters:
    start - index of the first type in frame to write.
    end - index of last type in frame to write (exclusive).
  - writeFrameType
```
private void writeFrameType(java.lang.Object type)
```
  - getSize
```
final int getSize()
```
    Returns the size of the bytecode of this method.
    
    Returns:
    the size of the bytecode of this method.
  - put
```
final void put(ByteVector out)
```
    Puts the bytecode of this method in the given byte vector.
    
    Parameters:
    out - the byte vector into which the bytecode of this method must be copied.
  - resizeInstructions
```
private void resizeInstructions()
```
    Resizes and replaces the temporary instructions inserted by Label.resolve(org.springframework.asm.MethodWriter, int, byte[]) for wide forward jumps, while keeping jump offsets and instruction addresses consistent. This may require to resize other existing instructions, or even to introduce new instructions: for example, increasing the size of an instruction by 2 at the middle of a method can increases the offset of an IFEQ instruction from 32766 to 32768, in which case IFEQ 32766 must be replaced with IFNEQ 8 GOTO_W 32765. This, in turn, may require to increase the size of another jump instruction, and so on... All these operations are handled automatically by this method.
    This method must be called after all the method that is being built has been visited. In particular, the Label objects used to construct the method are no longer valid after this method has been called.
  - readUnsignedShort
```
static int readUnsignedShort(byte[] b,
                    int index)
```
    Reads an unsigned short value in the given byte array.
    
    Parameters:
    b - a byte array.
    index - the start index of the value to be read.
    
    Returns:
    the read value.
  - readShort
```
static short readShort(byte[] b,
              int index)
```
    Reads a signed short value in the given byte array.
    
    Parameters:
    b - a byte array.
    index - the start index of the value to be read.
    
    Returns:
    the read value.
  - readInt
```
static int readInt(byte[] b,
          int index)
```
    Reads a signed int value in the given byte array.
    
    Parameters:
    b - a byte array.
    index - the start index of the value to be read.
    
    Returns:
    the read value.
  - writeShort
```
static void writeShort(byte[] b,
              int index,
              int s)
```
    Writes a short value in the given byte array.
    
    Parameters:
    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.
  - getNewOffset
```
static int getNewOffset(int[] indexes,
               int[] sizes,
               int begin,
               int end)
```
    Computes the future value of a bytecode offset.
    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').
    
    Parameters:
    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.
    
    Returns:
    the future value of the given bytecode offset.
  - getNewOffset
```
static void getNewOffset(int[] indexes,
                int[] sizes,
                Label label)
```
    Updates the offset of the given label.
    
    Parameters:
    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.

Class MethodWriter

Field Summary

Fields inherited from class org.springframework.asm.MethodVisitor

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ACC_CONSTRUCTOR

SAME_FRAME

SAME_LOCALS_1_STACK_ITEM_FRAME

RESERVED

SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED

CHOP_FRAME

SAME_FRAME_EXTENDED

APPEND_FRAME

FULL_FRAME

FRAMES

MAXS

NOTHING

cw

access

name

desc

descriptor

signature

classReaderOffset

classReaderLength

exceptionCount

exceptions

annd

anns

ianns

panns

ipanns

synthetics

attrs

code

maxStack

maxLocals

currentLocals

frameCount

stackMap

previousFrameOffset

previousFrame

frame

handlerCount

firstHandler

lastHandler

localVarCount

localVar

localVarTypeCount

localVarType

lineNumberCount

lineNumber

cattrs

resize

subroutines

compute

labels

previousBlock

currentBlock

stackSize

maxStackSize

Constructor Detail

MethodWriter

Method Detail

visitAnnotationDefault

visitAnnotation

visitParameterAnnotation

visitAttribute

visitCode

visitFrame

visitInsn

visitIntInsn

visitVarInsn

visitTypeInsn

visitFieldInsn

visitMethodInsn

visitInvokeDynamicInsn

visitJumpInsn