Mercurial > hg > openjdk > jdk9 > jaxp
view src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/Constant.java @ 1113:2fdbfbde3bc0
8162572: Update License Header for all JAXP sources
Reviewed-by: lancea
author | joehw |
---|---|
date | Mon, 17 Apr 2017 16:24:10 -0700 |
parents | 2bfaf29cc90b |
children |
line wrap: on
line source
/* * 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 com.sun.org.apache.bcel.internal.Constants; import java.io.*; /** * Abstract superclass for classes to represent the different constant types * in the constant pool of a class file. The classes keep closely to * the JVM specification. * * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> */ public abstract class Constant implements Cloneable, Node, Serializable { /* In fact this tag is redundant since we can distinguish different * `Constant' objects by their type, i.e., via `instanceof'. In some * places we will use the tag for switch()es anyway. * * First, we want match the specification as closely as possible. Second we * need the tag as an index to select the corresponding class name from the * `CONSTANT_NAMES' array. */ protected byte tag; Constant(byte tag) { this.tag = tag; } /** * 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 abstract void accept(Visitor v); public abstract void dump(DataOutputStream file) throws IOException; /** * @return Tag of constant, i.e., its type. No setTag() method to avoid * confusion. */ public final byte getTag() { return tag; } /** * @return String representation. */ public String toString() { return Constants.CONSTANT_NAMES[tag] + "[" + tag + "]"; } /** * @return deep copy of this constant */ public Constant copy() { try { return (Constant)super.clone(); } catch(CloneNotSupportedException e) {} return null; } public Object clone() throws CloneNotSupportedException { return super.clone(); } /** * Read one constant from the given file, the type depends on a tag byte. * * @param file Input stream * @return Constant object */ static final Constant readConstant(DataInputStream file) throws IOException, ClassFormatException { byte b = file.readByte(); // Read tag byte switch(b) { case Constants.CONSTANT_Class: return new ConstantClass(file); case Constants.CONSTANT_Fieldref: return new ConstantFieldref(file); case Constants.CONSTANT_Methodref: return new ConstantMethodref(file); case Constants.CONSTANT_InterfaceMethodref: return new ConstantInterfaceMethodref(file); case Constants.CONSTANT_String: return new ConstantString(file); case Constants.CONSTANT_Integer: return new ConstantInteger(file); case Constants.CONSTANT_Float: return new ConstantFloat(file); case Constants.CONSTANT_Long: return new ConstantLong(file); case Constants.CONSTANT_Double: return new ConstantDouble(file); case Constants.CONSTANT_NameAndType: return new ConstantNameAndType(file); case Constants.CONSTANT_Utf8: return new ConstantUtf8(file); default: throw new ClassFormatException("Invalid byte tag in constant pool: " + b); } } }