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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 colection of local variables in a method. This attribute is contained in the Code attribute.
See Also:
Version:$Id: LocalVariableTable.java 1749603 2016-06-21 20:50:19Z ggregory $
/** * This class represents colection of local variables in a * method. This attribute is contained in the <em>Code</em> attribute. * * @version $Id: LocalVariableTable.java 1749603 2016-06-21 20:50:19Z ggregory $ * @see Code * @see LocalVariable */
public class LocalVariableTable extends Attribute { private LocalVariable[] local_variable_table; // variables
Initialize from another object. Note that both objects use the same references (shallow copy). Use copy() for a physical copy.
/** * Initialize from another object. Note that both objects use the same * references (shallow copy). Use copy() for a physical copy. */
public LocalVariableTable(final LocalVariableTable c) { this(c.getNameIndex(), c.getLength(), c.getLocalVariableTable(), c.getConstantPool()); }
Params:
  • name_index – Index in constant pool to `LocalVariableTable'
  • length – Content length in bytes
  • local_variable_table – Table of local variables
  • constant_pool – Array of constants
/** * @param name_index Index in constant pool to `LocalVariableTable' * @param length Content length in bytes * @param local_variable_table Table of local variables * @param constant_pool Array of constants */
public LocalVariableTable(final int name_index, final int length, final LocalVariable[] local_variable_table, final ConstantPool constant_pool) { super(Const.ATTR_LOCAL_VARIABLE_TABLE, name_index, length, constant_pool); this.local_variable_table = local_variable_table; }
Construct object from input stream.
Params:
  • name_index – Index in constant pool
  • length – Content length in bytes
  • input – Input stream
  • constant_pool – Array of constants
Throws:
/** * Construct object from input stream. * @param name_index Index in constant pool * @param length Content length in bytes * @param input Input stream * @param constant_pool Array of constants * @throws IOException */
LocalVariableTable(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException { this(name_index, length, (LocalVariable[]) null, constant_pool); final int local_variable_table_length = input.readUnsignedShort(); local_variable_table = new LocalVariable[local_variable_table_length]; for (int i = 0; i < local_variable_table_length; i++) { local_variable_table[i] = new LocalVariable(input, constant_pool); } }
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.visitLocalVariableTable(this); }
Dump local variable table attribute to file stream in binary format.
Params:
  • file – Output file stream
Throws:
/** * Dump local variable 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(local_variable_table.length); for (final LocalVariable variable : local_variable_table) { variable.dump(file); } }
Returns:Array of local variables of method.
/** * @return Array of local variables of method. */
public final LocalVariable[] getLocalVariableTable() { return local_variable_table; }
Params:
  • index – the variable slot
Returns:the first LocalVariable that matches the slot or null if not found
Deprecated:since 5.2 because multiple variables can share the same slot, use getLocalVariable(int index, int pc) instead.
/** * * @param index the variable slot * * @return the first LocalVariable that matches the slot or null if not found * * @deprecated since 5.2 because multiple variables can share the * same slot, use getLocalVariable(int index, int pc) instead. */
@java.lang.Deprecated public final LocalVariable getLocalVariable( final int index ) { for (final LocalVariable variable : local_variable_table) { if (variable.getIndex() == index) { return variable; } } return null; }
Params:
  • index – the variable slot
  • pc – the current pc that this variable is alive
Returns:the LocalVariable that matches or null if not found
/** * * @param index the variable slot * @param pc the current pc that this variable is alive * * @return the LocalVariable that matches or null if not found */
public final LocalVariable getLocalVariable( final int index, final int pc ) { for (final LocalVariable variable : local_variable_table) { if (variable.getIndex() == index) { final int start_pc = variable.getStartPC(); final int end_pc = start_pc + variable.getLength(); if ((pc >= start_pc) && (pc <= end_pc)) { return variable; } } } return null; } public final void setLocalVariableTable( final LocalVariable[] local_variable_table ) { this.local_variable_table = local_variable_table; }
Returns:String representation.
/** * @return String representation. */
@Override public final String toString() { final StringBuilder buf = new StringBuilder(); for (int i = 0; i < local_variable_table.length; i++) { buf.append(local_variable_table[i]); if (i < local_variable_table.length - 1) { buf.append('\n'); } } return buf.toString(); }
Returns:deep copy of this attribute
/** * @return deep copy of this attribute */
@Override public Attribute copy( final ConstantPool _constant_pool ) { final LocalVariableTable c = (LocalVariableTable) clone(); c.local_variable_table = new LocalVariable[local_variable_table.length]; for (int i = 0; i < local_variable_table.length; i++) { c.local_variable_table[i] = local_variable_table[i].copy(); } c.setConstantPool(_constant_pool); return c; } public final int getTableLength() { return local_variable_table == null ? 0 : local_variable_table.length; } }