LocalVariableInstruction (Apache Commons BCEL 6.6.1 API)

org.apache.bcel.generic

## Class LocalVariableInstruction

- java.lang.Object
- - org.apache.bcel.generic.Instruction
  - - org.apache.bcel.generic.LocalVariableInstruction

- All Implemented Interfaces:
    Cloneable, IndexedInstruction, TypedInstruction
  Direct Known Subclasses:
    IINC, LoadInstruction, StoreInstruction

      public abstract class LocalVariableInstruction
      extends Instruction
      implements TypedInstruction, IndexedInstruction

  Abstract super class for instructions dealing with local variables.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected int` | `n` Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter

    - ### Fields inherited from class org.apache.bcel.generic.Instruction

      `length, opcode`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `LocalVariableInstruction(short opcode, short cTag, int n)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `dump(DataOutputStream out)` Dump instruction as byte code to stream out.
    `short` | `getCanonicalTag()`
    `int` | `getIndex()`
    `Type` | `getType(ConstantPoolGen cp)` Returns the type associated with the instruction - in case of ALOAD or ASTORE Type.OBJECT is returned.
    `protected void` | `initFromFile(ByteSequence bytes, boolean wide)` Read needed data (e.g.
    `void` | `setIndex(int n)` Set the local variable index.
    `String` | `toString(boolean verbose)` Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"

    - ### Methods inherited from class org.apache.bcel.generic.Instruction

      `accept, consumeStack, copy, equals, getComparator, getLength, getName, getOpcode, hashCode, isValidByte, isValidShort, produceStack, readInstruction, setComparator, toString, toString`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### n

          @Deprecated
          protected int n

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

  - ### Constructor Detail

    - #### LocalVariableInstruction

          protected LocalVariableInstruction(short opcode,
                                             short cTag,
                                             int n)

      Parameters:
        `opcode` - Instruction opcode
        `cTag` - Instruction number for compact version, ALOAD_0, e.g.
        `n` - local variable index (unsigned short)

  - ### Method Detail

    - #### dump

          public void dump(DataOutputStream out)
                    throws IOException

      Dump instruction as byte code to stream out.
      Overrides:
        `dump` in class `Instruction`
      Parameters:
        `out` - Output stream
      Throws:
        `IOException`

    - #### getCanonicalTag

          public short getCanonicalTag()

      Returns:
        canonical tag for instruction, e.g., ALOAD for ALOAD_0

    - #### getIndex

          public final int getIndex()

      Specified by:
        `getIndex` in interface `IndexedInstruction`
      Returns:
        local variable index (n) referred by this instruction.

    - #### getType

          public Type getType(ConstantPoolGen cp)

      Returns the type associated with the instruction - in case of ALOAD or ASTORE Type.OBJECT is returned. This is just a bit incorrect, because ALOAD and ASTORE may work on every ReferenceType (including Type.NULL) and ASTORE may even work on a ReturnaddressType .
      Specified by:
        `getType` in interface `TypedInstruction`
      Returns:
        type associated with the instruction

    - #### initFromFile

          protected void initFromFile(ByteSequence bytes,
                                      boolean wide)
                               throws IOException

      Read needed data (e.g. index) from file.

           (ILOAD <= tag <= ALOAD_3) || (ISTORE <= tag <= ASTORE_3)

      Overrides:
        `initFromFile` in class `Instruction`
      Parameters:
        `bytes` - byte sequence to read from
        `wide` - "wide" instruction flag
      Throws:
        `IOException` - may be thrown if the implementation needs to read data from the file

    - #### setIndex

          public void setIndex(int n)

      Set the local variable index. also updates opcode and length TODO Why?
      Specified by:
        `setIndex` in interface `IndexedInstruction`
      See Also:
        `setIndexOnly(int)`

    - #### toString

          public String toString(boolean verbose)

      Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"
      Overrides:
        `toString` in class `Instruction`
      Parameters:
        `verbose` - long/short format switch
      Returns:
        mnemonic for instruction

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