/*
 * Copyright (c) 2009, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.internal.module;

import java.util.Set;

Utility class for checking module, package, and class names.
/** * Utility class for checking module, package, and class names. */
public final class Checks { private Checks() { }
Checks a name to ensure that it's a legal module name.
Throws:
  • IllegalArgumentException – if name is null or not a legal module name
/** * Checks a name to ensure that it's a legal module name. * * @throws IllegalArgumentException if name is null or not a legal * module name */
public static String requireModuleName(String name) { if (name == null) throw new IllegalArgumentException("Null module name"); int next; int off = 0; while ((next = name.indexOf('.', off)) != -1) { String id = name.substring(off, next); if (!isJavaIdentifier(id)) { throw new IllegalArgumentException(name + ": Invalid module name" + ": '" + id + "' is not a Java identifier"); } off = next+1; } String last = name.substring(off); if (!isJavaIdentifier(last)) { throw new IllegalArgumentException(name + ": Invalid module name" + ": '" + last + "' is not a Java identifier"); } return name; }
Returns true if the given name is a legal module name.
/** * Returns {@code true} if the given name is a legal module name. */
public static boolean isModuleName(String name) { int next; int off = 0; while ((next = name.indexOf('.', off)) != -1) { String id = name.substring(off, next); if (!isJavaIdentifier(id)) return false; off = next+1; } String last = name.substring(off); return isJavaIdentifier(last); }
Checks a name to ensure that it's a legal package name.
Throws:
  • IllegalArgumentException – if name is null or not a legal package name
/** * Checks a name to ensure that it's a legal package name. * * @throws IllegalArgumentException if name is null or not a legal * package name */
public static String requirePackageName(String name) { return requireTypeName("package name", name); }
Returns true if the given name is a legal package name.
/** * Returns {@code true} if the given name is a legal package name. */
public static boolean isPackageName(String name) { return isTypeName(name); }
Checks a name to ensure that it's a legal qualified class name
Throws:
  • IllegalArgumentException – if name is null or not a legal qualified class name
/** * Checks a name to ensure that it's a legal qualified class name * * @throws IllegalArgumentException if name is null or not a legal * qualified class name */
public static String requireServiceTypeName(String name) { return requireQualifiedClassName("service type name", name); }
Checks a name to ensure that it's a legal qualified class name.
Throws:
  • IllegalArgumentException – if name is null or not a legal qualified class name
/** * Checks a name to ensure that it's a legal qualified class name. * * @throws IllegalArgumentException if name is null or not a legal * qualified class name */
public static String requireServiceProviderName(String name) { return requireQualifiedClassName("service provider name", name); }
Checks a name to ensure that it's a legal qualified class name in a named package.
Throws:
  • IllegalArgumentException – if name is null or not a legal qualified class name in a named package
/** * Checks a name to ensure that it's a legal qualified class name in * a named package. * * @throws IllegalArgumentException if name is null or not a legal * qualified class name in a named package */
public static String requireQualifiedClassName(String what, String name) { requireTypeName(what, name); if (name.indexOf('.') == -1) throw new IllegalArgumentException(name + ": is not a qualified name of" + " a Java class in a named package"); return name; }
Returns true if the given name is a legal class name.
/** * Returns {@code true} if the given name is a legal class name. */
public static boolean isClassName(String name) { return isTypeName(name); }
Returns true if the given name is a legal type name.
/** * Returns {@code true} if the given name is a legal type name. */
private static boolean isTypeName(String name) { int next; int off = 0; while ((next = name.indexOf('.', off)) != -1) { String id = name.substring(off, next); if (!isJavaIdentifier(id)) return false; off = next+1; } String last = name.substring(off); return isJavaIdentifier(last); }
Checks if the given name is a legal type name.
Throws:
  • IllegalArgumentException – if name is null or not a legal type name
/** * Checks if the given name is a legal type name. * * @throws IllegalArgumentException if name is null or not a legal * type name */
private static String requireTypeName(String what, String name) { if (name == null) throw new IllegalArgumentException("Null " + what); int next; int off = 0; while ((next = name.indexOf('.', off)) != -1) { String id = name.substring(off, next); if (!isJavaIdentifier(id)) { throw new IllegalArgumentException(name + ": Invalid " + what + ": '" + id + "' is not a Java identifier"); } off = next + 1; } String last = name.substring(off); if (!isJavaIdentifier(last)) { throw new IllegalArgumentException(name + ": Invalid " + what + ": '" + last + "' is not a Java identifier"); } return name; }
Returns true if the given char sequence is a legal Java identifier, otherwise false.
/** * Returns true if the given char sequence is a legal Java identifier, * otherwise false. */
private static boolean isJavaIdentifier(CharSequence cs) { if (cs.length() == 0 || RESERVED.contains(cs)) return false; int first = Character.codePointAt(cs, 0); if (!Character.isJavaIdentifierStart(first)) return false; int i = Character.charCount(first); while (i < cs.length()) { int cp = Character.codePointAt(cs, i); if (!Character.isJavaIdentifierPart(cp)) return false; i += Character.charCount(cp); } return true; } // keywords, boolean and null literals, not allowed in identifiers private static final Set<String> RESERVED = Set.of( "abstract", "assert", "boolean", "break", "byte", "case", "catch", "char", "class", "const", "continue", "default", "do", "double", "else", "enum", "extends", "final", "finally", "float", "for", "goto", "if", "implements", "import", "instanceof", "int", "interface", "long", "native", "new", "package", "private", "protected", "public", "return", "short", "static", "strictfp", "super", "switch", "synchronized", "this", "throw", "throws", "transient", "try", "void", "volatile", "while", "true", "false", "null", "_" ); }