Source code: com/techtrader/modules/tools/bytecode/FieldInstruction.java

   package com.techtrader.modules.tools.bytecode;
   
   
   import java.lang.reflect.Field;
   import java.io.IOException;
   import java.io.DataInput;
   import java.io.DataOutput;
   
   import com.techtrader.modules.tools.bytecode.lowlevel.FieldEntry;
  import com.techtrader.modules.tools.bytecode.visitor.BCVisitor;
  
  
  /**
   *  Represents an instruction that takes as an argument a field to operate on.
   *  Examples include GETFIELD, GETSTATIC, SETFIELD, SETSTATIC.
   *
   *  @author    Abe White
   */
  public abstract class FieldInstruction
    extends Instruction
  {
    private int _index = 0;
  
  
    protected FieldInstruction (Code owner, int opcode)
    {
      super (owner);
      _opcode = opcode;  
    }
  
  
    /**
     *  Get the index of the ComplexEntry in the constant pool describing
      *  the field to operate on.
     */
    public int getFieldIndex ()
    {
      return _index;
    }
  
  
    /**
     *  Set the index of the ComplexEntry in the constant pool describing
      *  the field to operate on.
     */
    public void setFieldIndex (int index)
    {
      _index = index;
    }
  
  
    /**
      *  Set the field to operate on.
     *  
     *  @return    this Instruction, for method chaining
     */
    public FieldInstruction setField (BCField field)
    {
      BCClass ownerType = field.getOwner ();
      return setField (field.getName (), field.getTypeName (), 
        ownerType.getName ());
    }
  
  
    /**
     *  Set the field to operate on.
     *  
     *  @return    this Instruction, for method chaining
     */
    public FieldInstruction setField (Field field)
    {
      return setField (field.getName (), field.getType ().getName (),
        field.getDeclaringClass ().getName ());
    }
  
  
    /**
     *  Set the field to operate on.
     *  
     *  @return    this Instruction, for method chaining
     */
    public FieldInstruction setField (String name, String type, 
      String ownerType)
    {
      String internalType = BCHelper.getInternalForm (type, true);
      String internalOwner = BCHelper.getInternalForm(ownerType, false);
  
      _index = _owner.getPool ().setComplex (0, name, internalType, 
        internalOwner, FieldEntry.class);
  
      return this;
    }
  
    
    /**
     *  Set the field to operate on.
     *  
     *  @return    this Instruction, for method chaining
     */
   public FieldInstruction setField (String name, Class type, String ownerType)
   {
     String typeName = (type == null) ? null : type.getName ();
     return setField (name, typeName, ownerType);
   }
 
 
   /**
    *  Set the field to operate on.
    *  
    *  @return    this Instruction, for method chaining
    */
   public FieldInstruction setField (String name, Class type, Class ownerType)
   {
     String typeName = (type == null) ? null : type.getName ();
     String ownerName = (ownerType == null) ? null : ownerType.getName ();
     return setField (name, typeName, ownerName);
   }
 
 
   /**
    *  Change the field name.
    *  
    *  @return    this Instruction, for method chaining
    */
   public FieldInstruction setFieldName (String name)
   {
     return setField (name, getFieldTypeName (), getFieldOwnerTypeName ());
   }
 
 
   /**
    *  Return true if the field is a member of the current class.
    */
   public boolean isFieldInCurrentClass ()
   {
     BCClass type = ((BCMethod) _owner.getOwner ()).getOwner ();
     return type.getName ().equals (getFieldOwnerTypeName ());
   }
 
 
   /**
    *  If the field is a member of the current class, then this method will
    *  retrieve the BCField object for it; otherwise it will return null.
    */
   public BCField getField ()
   {
     if (!isFieldInCurrentClass ())
       return null;
 
     return ((BCMethod) _owner.getOwner ()).getOwner ().
       getField (getFieldName ());
   }
 
 
   /**
     *  Get the nam of the field to operate on.
    */
   public String getFieldName ()
   {
     return _owner.getPool ().getComplexName (_index);
   }  
 
 
   /**
    *  Get the type of the field.
    */
   public String getFieldTypeName ()
   {
     return BCHelper.getExternalForm 
       (_owner.getPool ().getComplexTypeName (_index), true);
   }
 
 
   /**
    *  Get the type of the field.
    */
   public Class getFieldType ()
     throws ClassNotFoundException
   {
     return BCHelper.classForName 
       (_owner.getPool ().getComplexTypeName (_index));
   }
 
 
   /**
    *  Get the type of the field.
    */
   public String getFieldOwnerTypeName ()
   {
     return BCHelper.getExternalForm 
       (_owner.getPool ().getComplexOwnerTypeName (_index), true);
   }
 
 
   /**
    *  Get the type of the field.
    */
   public Class getFieldOwnerType ()
     throws ClassNotFoundException
   {
     return BCHelper.classForName
       (_owner.getPool ().getComplexOwnerTypeName (_index));
   }
 
 
   /**
    *  FieldInstructions are equal if the field they reference is the same, 
    *  or if the field of either is unset.
    */
   public boolean equals (Object other)
   {
     if (other == this)
       return true;
     if (!(other instanceof FieldInstruction))
       return false;
     if (!super.equals (other))
       return false;
 
     FieldInstruction ins = (FieldInstruction) other;
 
     String s1 = getFieldName ();
     String s2 = ins.getFieldName ();
     if (!(s1.length () == 0 || s2.length () == 0 || s1.equals (s2)))
       return false;
 
     s1 = getFieldTypeName ();
     s2 = ins.getFieldTypeName ();
     if (!(s1.length () == 0 || s2.length () == 0 || s1.equals (s2)))
       return false;
     
     s1 = getFieldOwnerTypeName ();
     s2 = ins.getFieldOwnerTypeName ();
     if (!(s1.length () == 0 || s2.length () == 0 || s1.equals (s2)))
       return false;
 
     return true;
   }
 
 
   public int getLength ()
   {
     return super.getLength () + 2;
   }
 
 
   protected void copy (Instruction orig)
   {
     super.copy (orig);
     FieldInstruction origFI = (FieldInstruction) orig;
 
     setField (origFI.getFieldName (), origFI.getFieldTypeName (), 
       origFI.getFieldOwnerTypeName ());
   }
 
 
   protected void readData (DataInput in)
     throws IOException
   {
     _index = in.readUnsignedShort ();
   }
 
 
   protected void writeData (DataOutput out)
     throws IOException
   {
     out.writeShort (_index);
   }
 }