| /* |
| * Copyright (c) 2008, 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 com.sun.tracing; |
| |
| import java.util.HashSet; |
| import java.io.PrintStream; |
| import java.lang.reflect.Field; |
| import java.security.AccessController; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| import sun.security.action.GetPropertyAction; |
| |
| import sun.tracing.NullProviderFactory; |
| import sun.tracing.PrintStreamProviderFactory; |
| import sun.tracing.MultiplexProviderFactory; |
| import sun.tracing.dtrace.DTraceProviderFactory; |
| |
| /** |
| * {@code ProviderFactory} is a factory class used to create instances of |
| * providers. |
| * |
| * To enable tracing in an application, this class must be used to create |
| * instances of the provider interfaces defined by users. |
| * The system-defined factory is obtained by using the |
| * {@code getDefaultFactory()} static method. The resulting instance can be |
| * used to create any number of providers. |
| * |
| * @since 1.7 |
| */ |
| public abstract class ProviderFactory { |
| |
| protected ProviderFactory() {} |
| |
| /** |
| * Creates an implementation of a Provider interface. |
| * |
| * @param cls the provider interface to be defined. |
| * @return an implementation of {@code cls}, whose methods, when called, |
| * will trigger tracepoints in the application. |
| * @throws NullPointerException if cls is null |
| * @throws IllegalArgumentException if the class definition contains |
| * non-void methods |
| */ |
| public abstract <T extends Provider> T createProvider(Class<T> cls); |
| |
| /** |
| * Returns an implementation of a {@code ProviderFactory} which |
| * creates instances of Providers. |
| * |
| * The created Provider instances will be linked to all appropriate |
| * and enabled system-defined tracing mechanisms in the JDK. |
| * |
| * @return a {@code ProviderFactory} that is used to create Providers. |
| */ |
| public static ProviderFactory getDefaultFactory() { |
| HashSet<ProviderFactory> factories = new HashSet<ProviderFactory>(); |
| |
| // Try to instantiate a DTraceProviderFactory |
| String prop = AccessController.doPrivileged( |
| new GetPropertyAction("com.sun.tracing.dtrace")); |
| |
| if ( (prop == null || !prop.equals("disable")) && |
| DTraceProviderFactory.isSupported() ) { |
| factories.add(new DTraceProviderFactory()); |
| } |
| |
| // Try to instantiate an output stream factory |
| prop = AccessController.doPrivileged( |
| new GetPropertyAction("sun.tracing.stream")); |
| if (prop != null) { |
| for (String spec : prop.split(",")) { |
| PrintStream ps = getPrintStreamFromSpec(spec); |
| if (ps != null) { |
| factories.add(new PrintStreamProviderFactory(ps)); |
| } |
| } |
| } |
| |
| // See how many factories we instantiated, and return an appropriate |
| // factory that encapsulates that. |
| if (factories.size() == 0) { |
| return new NullProviderFactory(); |
| } else if (factories.size() == 1) { |
| return factories.toArray(new ProviderFactory[1])[0]; |
| } else { |
| return new MultiplexProviderFactory(factories); |
| } |
| } |
| |
| private static PrintStream getPrintStreamFromSpec(final String spec) { |
| try { |
| // spec is in the form of <class>.<field>, where <class> is |
| // a fully specified class name, and <field> is a static member |
| // in that class. The <field> must be a 'PrintStream' or subtype |
| // in order to be used. |
| final int fieldpos = spec.lastIndexOf('.'); |
| final Class<?> cls = Class.forName(spec.substring(0, fieldpos)); |
| |
| Field f = AccessController.doPrivileged(new PrivilegedExceptionAction<Field>() { |
| public Field run() throws NoSuchFieldException { |
| return cls.getField(spec.substring(fieldpos + 1)); |
| } |
| }); |
| |
| return (PrintStream)f.get(null); |
| } catch (ClassNotFoundException e) { |
| throw new AssertionError(e); |
| } catch (IllegalAccessException e) { |
| throw new AssertionError(e); |
| } catch (PrivilegedActionException e) { |
| throw new AssertionError(e); |
| } |
| } |
| } |
| |