Class AdviceAdapter

java.lang.Object
org.objectweb.asm.MethodAdapter
org.objectweb.asm.commons.LocalVariablesSorter
org.objectweb.asm.commons.GeneratorAdapter
org.objectweb.asm.commons.AdviceAdapter
All Implemented Interfaces:
MethodVisitor, Opcodes
public abstract class AdviceAdapter extends GeneratorAdapter implements Opcodes
A MethodAdapter to insert before, after and around advices in methods and constructors.

The behavior for constructors is like this:

  1. as long as the INVOKESPECIAL for the object initialization has not been reached, every bytecode instruction is dispatched in the ctor code visitor
  2. when this one is reached, it is only added in the ctor code visitor and a JP invoke is added
  3. after that, only the other code visitor receives the instructions
Author:
Eugene Kuleshov, Eric Bruneton

  • Field Details

    • methodAccess

      protected int methodAccess

    • methodDesc

      protected String methodDesc

  • Constructor Details

    • AdviceAdapter

      protected AdviceAdapter(MethodVisitor mv, int access, String name, String desc)
      Creates a new AdviceAdapter.
      Parameters:
      mv - the method visitor to which this adapter delegates calls.
      access - the method's access flags (see Opcodes).
      name - the method's name.
      desc - the method's descriptor (see Type).

  • Method Details

    • visitCode

      public void visitCode()
      Description copied from interface: MethodVisitor
      Starts the visit of the method's code, if any (i.e. non abstract method).
      Specified by:
      visitCode in interface MethodVisitor
      Overrides:
      visitCode in class MethodAdapter

    • visitLabel

      public void visitLabel(Label label)
      Description copied from interface: MethodVisitor
      Visits a label. A label designates the instruction that will be visited just after it.
      Specified by:
      visitLabel in interface MethodVisitor
      Overrides:
      visitLabel in class MethodAdapter
      Parameters:
      label - a Label object.

    • visitInsn

      public void visitInsn(int opcode)
      Description copied from interface: MethodVisitor
      Visits a zero operand instruction.
      Specified by:
      visitInsn in interface MethodVisitor
      Overrides:
      visitInsn in class MethodAdapter
      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.

    • visitVarInsn

      public void visitVarInsn(int opcode, int var)
      Description copied from interface: MethodVisitor
      Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.
      Specified by:
      visitVarInsn in interface MethodVisitor
      Overrides:
      visitVarInsn in class LocalVariablesSorter
      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.

    • visitFieldInsn

      public void visitFieldInsn(int opcode, String owner, String name, String desc)
      Description copied from interface: MethodVisitor
      Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.
      Specified by:
      visitFieldInsn in interface MethodVisitor
      Overrides:
      visitFieldInsn in class MethodAdapter
      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).

    • visitIntInsn

      public void visitIntInsn(int opcode, int operand)
      Description copied from interface: MethodVisitor
      Visits an instruction with a single int operand.
      Specified by:
      visitIntInsn in interface MethodVisitor
      Overrides:
      visitIntInsn in class MethodAdapter
      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.

    • visitLdcInsn

      public void visitLdcInsn(Object cst)
      Description copied from interface: MethodVisitor
      Visits a LDC instruction.
      Specified by:
      visitLdcInsn in interface MethodVisitor
      Overrides:
      visitLdcInsn in class MethodAdapter
      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 (or a Type for .class constants, for classes whose version is 49.0 or more).

    • visitMultiANewArrayInsn

      public void visitMultiANewArrayInsn(String desc, int dims)
      Description copied from interface: MethodVisitor
      Visits a MULTIANEWARRAY instruction.
      Specified by:
      visitMultiANewArrayInsn in interface MethodVisitor
      Overrides:
      visitMultiANewArrayInsn in class MethodAdapter
      Parameters:
      desc - an array type descriptor (see Type).
      dims - number of dimensions of the array to allocate.

    • visitTypeInsn

      public void visitTypeInsn(int opcode, String type)
      Description copied from interface: MethodVisitor
      Visits a type instruction. A type instruction is an instruction that takes the internal name of a class as parameter.
      Specified by:
      visitTypeInsn in interface MethodVisitor
      Overrides:
      visitTypeInsn in class MethodAdapter
      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).

    • visitMethodInsn

      public void visitMethodInsn(int opcode, String owner, String name, String desc)
      Description copied from interface: MethodVisitor
      Visits a method instruction. A method instruction is an instruction that invokes a method.
      Specified by:
      visitMethodInsn in interface MethodVisitor
      Overrides:
      visitMethodInsn in class MethodAdapter
      Parameters:
      opcode - the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE or INVOKEDYNAMIC.
      owner - the internal name of the method's owner class (see getInternalName) or Opcodes.INVOKEDYNAMIC_OWNER.
      name - the method's name.
      desc - the method's descriptor (see Type).

    • visitJumpInsn

      public void visitJumpInsn(int opcode, Label label)
      Description copied from interface: MethodVisitor
      Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.
      Specified by:
      visitJumpInsn in interface MethodVisitor
      Overrides:
      visitJumpInsn in class MethodAdapter
      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.

    • visitLookupSwitchInsn

      public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels)
      Description copied from interface: MethodVisitor
      Visits a LOOKUPSWITCH instruction.
      Specified by:
      visitLookupSwitchInsn in interface MethodVisitor
      Overrides:
      visitLookupSwitchInsn in class MethodAdapter
      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.

    • visitTableSwitchInsn

      public void visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels)
      Description copied from interface: MethodVisitor
      Visits a TABLESWITCH instruction.
      Specified by:
      visitTableSwitchInsn in interface MethodVisitor
      Overrides:
      visitTableSwitchInsn in class MethodAdapter
      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.

    • onMethodEnter

      protected void onMethodEnter()
      Called at the beginning of the method or after super class class call in the constructor.

      Custom code can use or change all the local variables, but should not change state of the stack.

    • onMethodExit

      protected void onMethodExit(int opcode)
      Called before explicit exit from the method using either return or throw. Top element on the stack contains the return value or exception instance. For example: 
        public void onMethodExit(int opcode) {
    if(opcode==RETURN) {
        visitInsn(ACONST_NULL);
    } else if(opcode==ARETURN || opcode==ATHROW) {
        dup();
    } else {
        if(opcode==LRETURN || opcode==DRETURN) {
            dup2();
        } else {
            dup();
        }
        box(Type.getReturnType(this.methodDesc));
    }
    visitIntInsn(SIPUSH, opcode);
    visitMethodInsn(INVOKESTATIC, owner, "onExit", "(Ljava/lang/Object;I)V");
  }

  // an actual call back method
  public static void onExit(Object param, int opcode) {
    ...


      Custom code can use or change all the local variables, but should not change state of the stack.
      Parameters:
      opcode - one of the RETURN, IRETURN, FRETURN, ARETURN, LRETURN, DRETURN or ATHROW