/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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 is derived from Attribute and represents a constant value, i.e., a default value for initializing a class field. This class is instantiated by the Attribute.readAttribute() method.
See Also:
Version:$Id: ConstantValue.java 1749603 2016-06-21 20:50:19Z ggregory $
/** * This class is derived from <em>Attribute</em> and represents a constant * value, i.e., a default value for initializing a class field. * This class is instantiated by the <em>Attribute.readAttribute()</em> method. * * @version $Id: ConstantValue.java 1749603 2016-06-21 20:50:19Z ggregory $ * @see Attribute */
public final class ConstantValue extends Attribute { private int constantvalue_index;
Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a physical copy.
/** * Initialize from another object. Note that both objects use the same * references (shallow copy). Use clone() for a physical copy. */
public ConstantValue(final ConstantValue c) { this(c.getNameIndex(), c.getLength(), c.getConstantValueIndex(), c.getConstantPool()); }
Construct object from input stream.
Params:
  • name_index – Name 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 Name index in constant pool * @param length Content length in bytes * @param input Input stream * @param constant_pool Array of constants * @throws IOException */
ConstantValue(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException { this(name_index, length, input.readUnsignedShort(), constant_pool); }
Params:
  • name_index – Name index in constant pool
  • length – Content length in bytes
  • constantvalue_index – Index in constant pool
  • constant_pool – Array of constants
/** * @param name_index Name index in constant pool * @param length Content length in bytes * @param constantvalue_index Index in constant pool * @param constant_pool Array of constants */
public ConstantValue(final int name_index, final int length, final int constantvalue_index, final ConstantPool constant_pool) { super(Const.ATTR_CONSTANT_VALUE, name_index, length, constant_pool); this.constantvalue_index = constantvalue_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.
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.visitConstantValue(this); }
Dump constant value attribute to file stream on binary format.
Params:
  • file – Output file stream
Throws:
/** * Dump constant value attribute to file stream on binary format. * * @param file Output file stream * @throws IOException */
@Override public final void dump( final DataOutputStream file ) throws IOException { super.dump(file); file.writeShort(constantvalue_index); }
Returns:Index in constant pool of constant value.
/** * @return Index in constant pool of constant value. */
public final int getConstantValueIndex() { return constantvalue_index; }
Params:
  • constantvalue_index – the index info the constant pool of this constant value
/** * @param constantvalue_index the index info the constant pool of this constant value */
public final void setConstantValueIndex( final int constantvalue_index ) { this.constantvalue_index = constantvalue_index; }
Returns:String representation of constant value.
/** * @return String representation of constant value. */
@Override public final String toString() { Constant c = super.getConstantPool().getConstant(constantvalue_index); String buf; int i; // Print constant to string depending on its type switch (c.getTag()) { case Const.CONSTANT_Long: buf = String.valueOf(((ConstantLong) c).getBytes()); break; case Const.CONSTANT_Float: buf = String.valueOf(((ConstantFloat) c).getBytes()); break; case Const.CONSTANT_Double: buf = String.valueOf(((ConstantDouble) c).getBytes()); break; case Const.CONSTANT_Integer: buf = String.valueOf(((ConstantInteger) c).getBytes()); break; case Const.CONSTANT_String: i = ((ConstantString) c).getStringIndex(); c = super.getConstantPool().getConstant(i, Const.CONSTANT_Utf8); buf = "\"" + Utility.convertString(((ConstantUtf8) c).getBytes()) + "\""; break; default: throw new IllegalStateException("Type of ConstValue invalid: " + c); } return buf; }
Returns:deep copy of this attribute
/** * @return deep copy of this attribute */
@Override public Attribute copy( final ConstantPool _constant_pool ) { final ConstantValue c = (ConstantValue) clone(); c.setConstantPool(_constant_pool); return c; } }