package de.fub.bytecode.classfile; import de.fub.bytecode.Constants; import java.io.*; /** * This class is derived from the abstract * Constant class * and represents a reference to a (external) class. * * @version $Id: ConstantClass.java,v 1.4 2001/08/08 14:01:11 dahm Exp $ * @author M. Dahm * @see Constant */ public final class ConstantClass extends Constant implements ConstantObject { private int name_index; // Identical to ConstantString except for the name /** * Initialize from another object. */ public ConstantClass(ConstantClass c) { this(c.getNameIndex()); } /** * Initialize instance from file data. * * @param file Input stream * @throw IOException */ ConstantClass(DataInputStream file) throws IOException { this(file.readUnsignedShort()); } /** * @param name_index Name index in constant pool */ public ConstantClass(int name_index) { super(Constants.CONSTANT_Class); this.name_index = name_index; } /** * 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(Visitor v) { v.visitConstantClass(this); } /** * Dump constant class to file stream in binary format. * * @param file Output file stream * @throw IOException */ public final void dump(DataOutputStream file) throws IOException { file.writeByte(tag); file.writeShort(name_index); } /** * @return Name index in constant pool of class name. */ public final int getNameIndex() { return name_index; } /** * @param name_index. */ public final void setNameIndex(int name_index) { this.name_index = name_index; } /** @return String object */ public Object getConstantValue(ConstantPool cp) { Constant c = cp.getConstant(name_index, Constants.CONSTANT_Utf8); return ((ConstantUtf8)c).getBytes(); } /** @return dereferenced string */ public String getBytes(ConstantPool cp) { return (String)getConstantValue(cp); } /** * @return String representation. */ public final String toString() { return super.toString() + "(name_index = " + name_index + ")"; } }
