src/share/classes/java/lang/SafeVarargs.java

Print this page


   1 /*
   2  * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  68  * <blockquote><pre>
  69  * &#64;SafeVarargs // Not actually safe!
  70  * static void m(List&lt;String&gt;... stringLists) {
  71  *   Object[] array = stringLists;
  72  *   List&lt;Integer&gt; tmpList = Arrays.asList(42);
  73  *   array[0] = tmpList; // Semantically invalid, but compiles without warnings
  74  *   String s = stringLists[0].get(0); // Oh no, ClassCastException at runtime!
  75  * }
  76  * </pre></blockquote>
  77  *
  78  * leads to a {@code ClassCastException} at runtime.
  79  *
  80  * <p>Future versions of the platform may mandate compiler errors for
  81  * such unsafe operations.
  82  *
  83  * </ul>
  84  *
  85  * @since 1.7
  86  * @jls 4.7 Reifiable Types
  87  * @jls 8.4.1 Formal Parameters

  88  */
  89 @Documented
  90 @Retention(RetentionPolicy.RUNTIME)
  91 @Target({ElementType.CONSTRUCTOR, ElementType.METHOD})
  92 public @interface SafeVarargs {}
   1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  68  * <blockquote><pre>
  69  * &#64;SafeVarargs // Not actually safe!
  70  * static void m(List&lt;String&gt;... stringLists) {
  71  *   Object[] array = stringLists;
  72  *   List&lt;Integer&gt; tmpList = Arrays.asList(42);
  73  *   array[0] = tmpList; // Semantically invalid, but compiles without warnings
  74  *   String s = stringLists[0].get(0); // Oh no, ClassCastException at runtime!
  75  * }
  76  * </pre></blockquote>
  77  *
  78  * leads to a {@code ClassCastException} at runtime.
  79  *
  80  * <p>Future versions of the platform may mandate compiler errors for
  81  * such unsafe operations.
  82  *
  83  * </ul>
  84  *
  85  * @since 1.7
  86  * @jls 4.7 Reifiable Types
  87  * @jls 8.4.1 Formal Parameters
  88  * @jls 9.6.3.7 @SafeVarargs
  89  */
  90 @Documented
  91 @Retention(RetentionPolicy.RUNTIME)
  92 @Target({ElementType.CONSTRUCTOR, ElementType.METHOD})
  93 public @interface SafeVarargs {}