http://www.aspectj.org: The AspectJ weaver introduces advices to java classes
  • Andy Clement 
package org.aspectj.apache.bcel.classfile;

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import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;


This class represents a stack map entry recording the types of
local variables and the the of stack items at a given byte code offset.
See CLDC specification 5.3.1.2

Author: M. Dahm
See Also:
Version:$Id: StackMapEntry.java,v 1.5 2008/05/28 23:53:02 aclement Exp $
/**
 * This class represents a stack map entry recording the types of
 * local variables and the the of stack items at a given byte code offset.
 * See CLDC specification 5.3.1.2
 *
 * @version $Id: StackMapEntry.java,v 1.5 2008/05/28 23:53:02 aclement Exp $
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     StackMap
 * @see     StackMapType
 */
public final class StackMapEntry implements Cloneable {
  private int            byte_code_offset;
  private int            number_of_locals;
  private StackMapType[] types_of_locals;
  private int            number_of_stack_items;
  private StackMapType[] types_of_stack_items;
  private ConstantPool   constant_pool;

  
Construct object from file stream.

Params:
  • file – Input stream
Throws:
/**
   * Construct object from file stream.
   * @param file Input stream
   * @throws IOException
   */
  StackMapEntry(DataInputStream file, ConstantPool constant_pool) throws IOException
  {
    this(file.readShort(), file.readShort(), null, -1, null, constant_pool);

    types_of_locals = new StackMapType[number_of_locals];
    for(int i=0; i < number_of_locals; i++)
      types_of_locals[i] = new StackMapType(file, constant_pool);

    number_of_stack_items = file.readShort();
    types_of_stack_items = new StackMapType[number_of_stack_items];
    for(int i=0; i < number_of_stack_items; i++)
      types_of_stack_items[i] = new StackMapType(file, constant_pool);
  }

  public StackMapEntry(int byte_code_offset, int number_of_locals,
		       StackMapType[] types_of_locals,
		       int number_of_stack_items,
		       StackMapType[] types_of_stack_items,
		       ConstantPool constant_pool) {
    this.byte_code_offset = byte_code_offset;
    this.number_of_locals = number_of_locals;
    this.types_of_locals = types_of_locals;
    this.number_of_stack_items = number_of_stack_items;
    this.types_of_stack_items = types_of_stack_items;
    this.constant_pool = constant_pool;
  }

  
Dump stack map entry

Params:
  • file – Output file stream
Throws:
/**
   * Dump stack map entry
   *
   * @param file Output file stream
   * @throws IOException
   */ 
  public final void dump(DataOutputStream file) throws IOException
  {
    file.writeShort(byte_code_offset);

    file.writeShort(number_of_locals);
    for(int i=0; i < number_of_locals; i++)
      types_of_locals[i].dump(file);

    file.writeShort(number_of_stack_items);
    for(int i=0; i < number_of_stack_items; i++)
      types_of_stack_items[i].dump(file);
  }

  
Returns:String representation.
/**
   * @return String representation.
   */ 
  public final String toString() {
    StringBuffer buf = new StringBuffer("(offset=" + byte_code_offset);

    if(number_of_locals > 0) {
      buf.append(", locals={");

      for(int i=0; i < number_of_locals; i++) {
	buf.append(types_of_locals[i]);
	if(i < number_of_locals - 1)
	  buf.append(", ");
      }

      buf.append("}");
    }

    if(number_of_stack_items > 0) {
      buf.append(", stack items={");

      for(int i=0; i < number_of_stack_items; i++) {
	buf.append(types_of_stack_items[i]);
	if(i < number_of_stack_items - 1)
	  buf.append(", ");
      }

      buf.append("}");
    }

    buf.append(")");

    return buf.toString();    
  }


  public void           setByteCodeOffset(int b)               { byte_code_offset = b; }
  public int            getByteCodeOffset()                    { return byte_code_offset; }
  public void           setNumberOfLocals(int n)               { number_of_locals = n; }
  public int            getNumberOfLocals()                    { return number_of_locals; }
  public void           setTypesOfLocals(StackMapType[] t)     { types_of_locals = t; }
  public StackMapType[] getTypesOfLocals()                     { return types_of_locals; }
  public void           setNumberOfStackItems(int n)           { number_of_stack_items = n; }
  public int            getNumberOfStackItems()                { return number_of_stack_items; }
  public void           setTypesOfStackItems(StackMapType[] t) { types_of_stack_items = t; }
  public StackMapType[] getTypesOfStackItems()                 { return types_of_stack_items; }

  
Returns:deep copy of this object
/**
   * @return deep copy of this object
   */
  public StackMapEntry copy() {
    try {
      return (StackMapEntry)clone();
    } catch(CloneNotSupportedException e) {}

    return null;
  }

  
Called by objects that are traversing the nodes of the tree implicitely
defined by the contents of a Java class. I.e., the hierarchy of methods,
fields, attributes, etc. spawns a tree of objects.

Params:
  • v – Visitor object
/**
   * Called by objects that are traversing the nodes of the tree implicitely
   * defined by the contents of a Java class. I.e., the hierarchy of methods,
   * fields, attributes, etc. spawns a tree of objects.
   *
   * @param v Visitor object
   */
  public void accept(ClassVisitor v) {
    v.visitStackMapEntry(this);
  }

  
Returns:Constant pool used by this object.
/**
   * @return Constant pool used by this object.
   */   
  public final ConstantPool getConstantPool() { return constant_pool; }

  
Params:
  • constant_pool – Constant pool to be used for this object.
/**
   * @param constant_pool Constant pool to be used for this object.
   */   
  public final void setConstantPool(ConstantPool constant_pool) {
    this.constant_pool = constant_pool;
  }
}