--- /dev/null 2017-11-09 09:38:01.297999907 +0100 +++ new/src/jdk.jfr/share/classes/jdk/jfr/MetadataDefinition.java 2018-04-09 15:39:25.274022009 +0200 @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2016, 2018, 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.jfr; + +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; +import java.lang.annotation.Target; + +/** + * Meta annotation for defining new types of event metadata. + *

+ * In the following example, a transaction event is defined with two + * user-defined annotations, {@code @Severity} and {@code @TransactionId}. + * + *

+ * 
+ *{@literal @}MetadataDefinition
+ *{@literal @}Label("Severity")
+ *{@literal @}Description("Value between 0 and 100 that indicates severity. 100 is most severe.")
+ *{@literal @}Retention(RetentionPolicy.RUNTIME)
+ *{@literal @}Target({ ElementType.TYPE })
+ * public {@literal @}interface {@literal @}Severity {
+ *   int value() default 50;
+ * }
+ *
+ *{@literal @}MetadataDefinition
+ *{@literal @}Label("Transaction Id")
+ *{@literal @}Relational
+ *{@literal @}Retention(RetentionPolicy.RUNTIME)
+ *{@literal @}Target({ ElementType.FIELD })
+ * public {@literal @}interface {@literal @}Severity {
+ * }
+ *
+ *{@literal @}Severity(80)
+ *{@literal @}Label("Transaction Blocked");
+ * class TransactionBlocked extends Event {
+ *  {@literal @}TransactionId
+ *  {@literal @}Label("Transaction");
+ *   long transactionId;
+ *
+ *  {@literal @}TransactionId
+ *  {@literal @}Label("Transaction Blocker");
+ *   long transactionId;
+ * }
+ *
+ * 
+ * 
+ * + * Adding {@code @MetadataDefinition} to the declaration of {@code @Severity} and {@code @TransactionId} + * ensures the information is saved by Flight Recorder. + * + * @since 9 + */ +@Retention(RetentionPolicy.RUNTIME) +@Target({ ElementType.TYPE }) +public @interface MetadataDefinition { +}