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4a623a2b6d
8347163: Javadoc error in ConstantPoolBuilder after JDK-8342468 Reviewed-by: asotona Backport-of: bcefab5e55d4527a38dcab550581a734c1564608
83 lines
5.2 KiB
Java
83 lines
5.2 KiB
Java
/*
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* Copyright (c) 2023, 2025, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/**
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* <h2>Provides interfaces describing constant pool entries for the {@link java.lang.classfile} library.</h2>
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*
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* The {@code java.lang.classfile.constantpool} package contains interfaces describing constant pool entries in the
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* {@code class} file format. Constant pool entries are low-level models to faithfully represent the exact structure
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* of a {@code class} file.
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* <p>
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* Unless otherwise specified, passing {@code null} or an array or collection containing a {@code null} element as an
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* argument to a constructor or method of any Class-File API class or interface will cause a {@link NullPointerException}
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* to be thrown.
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*
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* <h2 id="reading">Reading the constant pool entries</h2>
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* When read from {@code class} files, the pool entries are lazily inflated; the contents of these entries, besides the
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* bare structure, are not evaluated to speed up parsing. Entries to users interest, usually accessed from other models
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* and elements, have their contents read on demand. For example, to search for methods, a user should filter first by
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* access flags and then by method name, and use {@link Utf8Entry#equalsString(String)} instead of checking equality
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* against {@link Utf8Entry#stringValue()}. This avoids inflation of UTF-8 entries as much as possible:
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* {@snippet lang="java" class="PackageSnippets" region="isStaticWorkMethod"}
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* <p>
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* The entries also define accessors to validated symbolic information with nominal descriptor abstractions from the
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* {@link java.lang.constant} package. These symbolic information accessors perform validation against the read
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* {@code class} files, and throw {@link IllegalArgumentException} when the accessed constant pool entry contains
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* invalid data. The nominal descriptors represent validated data, which saves users from extra validations in future
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* processing.
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* <p>
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* Due to the lazy nature of {@code class} file parsing, {@link IllegalArgumentException} indicating malformed
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* {@code class} file data can be thrown at any method invocation. For example, an exception may come from a {@link
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* ClassEntry} when it is first read from the constant pool (referring to an invalid index or wrong type of entry), when
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* its referred UTF-8 entry is expanded (malformed UTF-8 data), or when its symbolic information is accessed (the string
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* is not valid for a class entry).
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*
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* <h2 id="writing">Writing the constant pool entries</h2>
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* In general, users do not need to worry about working with the constant pool and its entries when writing {@code
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* class} files. Most Class-File API models and elements have two sets of factory methods: one that accepts symbolic
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* information representing the uses, and another that accepts constant pool entries. The constant pool builder
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* associated with {@code class} file builders, {@link ClassFileBuilder#constantPool}, automatically creates or reuses
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* pool entries from the symbolic information. Validated data in symbolic information helps {@code class} file
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* generation by avoiding extraneous parsing of raw constant pool entry data.
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* <p>
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* As always, users can use factories that accept constant pool entries if they already have them by hand, or if they
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* desire fine-grained control over {@code class} file generation.
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* <p>
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* If many models and elements are reused from another {@link ClassModel} in class building, the class building process
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* can use a constant pool builder that extends from the given {@code ClassModel}, available through {@link
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* ConstantPoolBuilder#of(ClassModel) ConstantPoolBuilder::of(ClassModel)}, so that byte data with constant pool
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* references can be copied in batch, speeding up class building. This is especially applicable to class transformations,
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* and {@link ClassFile.ConstantPoolSharingOption ConstantPoolSharingOption} exists to control this behavior.
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*
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* @jvms 4.4 The Constant Pool
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* @since 24
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*/
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package java.lang.classfile.constantpool;
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import java.lang.classfile.ClassFile;
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import java.lang.classfile.ClassFileBuilder;
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import java.lang.classfile.ClassModel;
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import java.lang.classfile.MethodModel;
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