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package com.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

This class represents a stack map attribute used for preverification of Java classes for the Java 2 Micro Edition (J2ME). This attribute is used by the KVM and contained within the Code attribute of a method. See CLDC specification 5.3.1.2
See Also:
Version:$Id: StackMap.java 1749603 2016-06-21 20:50:19Z ggregory $
/** * This class represents a stack map attribute used for * preverification of Java classes for the <a * href="http://java.sun.com/j2me/"> Java 2 Micro Edition</a> * (J2ME). This attribute is used by the <a * href="http://java.sun.com/products/cldc/">KVM</a> and contained * within the Code attribute of a method. See CLDC specification * 5.3.1.2 * * @version $Id: StackMap.java 1749603 2016-06-21 20:50:19Z ggregory $ * @see Code * @see StackMapEntry * @see StackMapType */
public final class StackMap extends Attribute { private StackMapEntry[] map; // Table of stack map entries /* * @param name_index Index of name * @param length Content length in bytes * @param map Table of stack map entries * @param constant_pool Array of constants */ public StackMap(final int name_index, final int length, final StackMapEntry[] map, final ConstantPool constant_pool) { super(Const.ATTR_STACK_MAP, name_index, length, constant_pool); this.map = map; }
Construct object from input stream.
Params:
  • name_index – Index of name
  • length – Content length in bytes
  • input – Input stream
  • constant_pool – Array of constants
Throws:
/** * Construct object from input stream. * * @param name_index Index of name * @param length Content length in bytes * @param input Input stream * @param constant_pool Array of constants * @throws IOException */
StackMap(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException { this(name_index, length, (StackMapEntry[]) null, constant_pool); final int map_length = input.readUnsignedShort(); map = new StackMapEntry[map_length]; for (int i = 0; i < map_length; i++) { map[i] = new StackMapEntry(input, constant_pool); } }
Dump line number table attribute to file stream in binary format.
Params:
  • file – Output file stream
Throws:
/** * Dump line number table attribute to file stream in binary format. * * @param file Output file stream * @throws IOException */
@Override public final void dump( final DataOutputStream file ) throws IOException { super.dump(file); file.writeShort(map.length); for (final StackMapEntry entry : map) { entry.dump(file); } }
Returns:Array of stack map entries
/** * @return Array of stack map entries */
public final StackMapEntry[] getStackMap() { return map; }
Params:
  • map – Array of stack map entries
/** * @param map Array of stack map entries */
public final void setStackMap( final StackMapEntry[] map ) { this.map = map; int len = 2; // Length of 'number_of_entries' field prior to the array of stack maps for (final StackMapEntry element : map) { len += element.getMapEntrySize(); } setLength(len); }
Returns:String representation.
/** * @return String representation. */
@Override public final String toString() { final StringBuilder buf = new StringBuilder("StackMap("); for (int i = 0; i < map.length; i++) { buf.append(map[i]); if (i < map.length - 1) { buf.append(", "); } } buf.append(')'); return buf.toString(); }
Returns:deep copy of this attribute
/** * @return deep copy of this attribute */
@Override public Attribute copy( final ConstantPool _constant_pool ) { final StackMap c = (StackMap) clone(); c.map = new StackMapEntry[map.length]; for (int i = 0; i < map.length; i++) { c.map[i] = map[i].copy(); } c.setConstantPool(_constant_pool); return c; }
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 */
@Override public void accept( final Visitor v ) { v.visitStackMap(this); } public final int getMapLength() { return map == null ? 0 : map.length; } }