LocalVariableTableAttribute.java

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package com.sun.jdo.api.persistence.enhancer.classfile;

import java.io.*;
import java.util.Vector;
import java.util.Enumeration;

/**
 * Represents the LocalVariableTable attribute within a
 * method in a class file.
 */

public class LocalVariableTableAttribute extends ClassAttribute {
  /* The expected attribute name */
    public static final String expectedAttrName = "LocalVariableTable";//NOI18N

  /* The list of local variables */
  private Vector localTable;

  /* public accessors */

  /**
   * Returns an enumeration of the local variables in the table
   * Each element is a LocalVariable
   */
  Enumeration variables() {
    return localTable.elements();
  }

  /**
   * Constructor for a local variable table
   */
  public LocalVariableTableAttribute(
	ConstUtf8 nameAttr, Vector lvarTable) {
    super(nameAttr);
    localTable = lvarTable;
  }

  /* package local methods */

  static LocalVariableTableAttribute read(
	ConstUtf8 attrName, DataInputStream data, CodeEnv env)
    throws IOException {
    int nVars = data.readUnsignedShort();
    Vector lvarTable = new Vector();
    while (nVars-- > 0) {
      lvarTable.addElement(LocalVariable.read(data, env));
    }
        
    return new LocalVariableTableAttribute(attrName, lvarTable);
  }

  void write(DataOutputStream out) throws IOException {
    out.writeShort(attrName().getIndex());
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    DataOutputStream tmp_out = new DataOutputStream(baos);
    tmp_out.writeShort(localTable.size());
    for (int i=0; i<localTable.size(); i++)
      ((LocalVariable) localTable.elementAt(i)).write(tmp_out);

    tmp_out.flush();
    byte tmp_bytes[] = baos.toByteArray();
    out.writeInt(tmp_bytes.length);
    out.write(tmp_bytes, 0, tmp_bytes.length);
  }

  void print(PrintStream out, int indent) {
    ClassPrint.spaces(out, indent);
    out.println("LocalVariables: ");//NOI18N
    for (int i=0; i<localTable.size(); i++) {
      ((LocalVariable) localTable.elementAt(i)).print(out, indent+2);
    }
  }
}