jdk8-mips64-public/jaxws: src/share/jaxws_classes/com/sun/xml/internal/ws/util/ServiceFinder.java@9c07ef4934dd (annotated)

src/share/jaxws_classes/com/sun/xml/internal/ws/util/ServiceFinder.java@9c07ef4934dd (annotated)

src/share/jaxws_classes/com/sun/xml/internal/ws/util/ServiceFinder.java

Thu, 31 Aug 2017 15:18:52 +0800

author: aoqi
date: Thu, 31 Aug 2017 15:18:52 +0800
changeset 637: 9c07ef4934dd
parent 368: 0989ad8c0860
parent 0: 373ffda63c9a
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 1997, 2013, 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.xml.internal.ws.util;
 import com.sun.istack.internal.NotNull;
 import com.sun.istack.internal.Nullable;
 import com.sun.xml.internal.ws.api.Component;
 import com.sun.xml.internal.ws.api.ComponentEx;
 import com.sun.xml.internal.ws.api.server.ContainerResolver;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.lang.reflect.Array;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.Iterator;
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 /**
  * A simple service-provider lookup mechanism.  A <i>service</i> is a
  * well-known set of interfaces and (usually abstract) classes.  A <i>service
  * provider</i> is a specific implementation of a service.  The classes in a
  * provider typically implement the interfaces and subclass the classes defined
  * in the service itself.  Service providers may be installed in an
  * implementation of the Java platform in the form of extensions, that is, jar
  * files placed into any of the usual extension directories.  Providers may
  * also be made available by adding them to the applet or application class
  * path or by some other platform-specific means.
  * <p/>
  * <p> In this lookup mechanism a service is represented by an interface or an
  * abstract class.  (A concrete class may be used, but this is not
  * recommended.)  A provider of a given service contains one or more concrete
  * classes that extend this <i>service class</i> with data and code specific to
  * the provider.  This <i>provider class</i> will typically not be the entire
  * provider itself but rather a proxy that contains enough information to
  * decide whether the provider is able to satisfy a particular request together
  * with code that can create the actual provider on demand.  The details of
  * provider classes tend to be highly service-specific; no single class or
  * interface could possibly unify them, so no such class has been defined.  The
  * only requirement enforced here is that provider classes must have a
  * zero-argument constructor so that they may be instantiated during lookup.
  * <p/>
  * <p> A service provider identifies itself by placing a provider-configuration
  * file in the resource directory <tt>META-INF/services</tt>.  The file's name
  * should consist of the fully-qualified name of the abstract service class.
  * The file should contain a list of fully-qualified concrete provider-class
  * names, one per line.  Space and tab characters surrounding each name, as
  * well as blank lines, are ignored.  The comment character is <tt>'#'</tt>
  * (<tt>0x23</tt>); on each line all characters following the first comment
  * character are ignored.  The file must be encoded in UTF-8.
  * <p/>
  * <p> If a particular concrete provider class is named in more than one
  * configuration file, or is named in the same configuration file more than
  * once, then the duplicates will be ignored.  The configuration file naming a
  * particular provider need not be in the same jar file or other distribution
  * unit as the provider itself.  The provider must be accessible from the same
  * class loader that was initially queried to locate the configuration file;
  * note that this is not necessarily the class loader that found the file.
  * <p/>
  * <p> <b>Example:</b> Suppose we have a service class named
  * <tt>java.io.spi.CharCodec</tt>.  It has two abstract methods:
  * <p/>
  * <pre>
  *   public abstract CharEncoder getEncoder(String encodingName);
  *   public abstract CharDecoder getDecoder(String encodingName);
  * </pre>
  * <p/>
  * Each method returns an appropriate object or <tt>null</tt> if it cannot
  * translate the given encoding.  Typical <tt>CharCodec</tt> providers will
  * support more than one encoding.
  * <p/>
  * <p> If <tt>sun.io.StandardCodec</tt> is a provider of the <tt>CharCodec</tt>
  * service then its jar file would contain the file
  * <tt>META-INF/services/java.io.spi.CharCodec</tt>.  This file would contain
  * the single line:
  * <p/>
  * <pre>
  *   sun.io.StandardCodec    # Standard codecs for the platform
  * </pre>
  * <p/>
  * To locate an codec for a given encoding name, the internal I/O code would
  * do something like this:
  * <p/>
  * <pre>
  *   CharEncoder getEncoder(String encodingName) {
  *       for( CharCodec cc : ServiceFinder.find(CharCodec.class) ) {
  *           CharEncoder ce = cc.getEncoder(encodingName);
  *           if (ce != null)
  *               return ce;
  *       }
  *       return null;
  *   }
  * </pre>
  * <p/>
  * The provider-lookup mechanism always executes in the security context of the
  * caller.  Trusted system code should typically invoke the methods in this
  * class from within a privileged security context.
  *
  * @author Mark Reinhold
  * @version 1.11, 03/12/19
  * @since 1.3
  */
 public final class ServiceFinder<T> implements Iterable<T> {
     private static final String prefix = "META-INF/services/";
     private static WeakHashMap<ClassLoader, ConcurrentHashMap<String, ServiceName[]>> serviceNameCache
              = new WeakHashMap<ClassLoader, ConcurrentHashMap<String, ServiceName[]>>();
     private final Class<T> serviceClass;
     private final @Nullable ClassLoader classLoader;
     private final @Nullable ComponentEx component;
     private static class ServiceName {
         final String className;
         final URL config;
         public ServiceName(String className, URL config) {
             this.className = className;
             this.config = config;
         }
     }
     public static <T> ServiceFinder<T> find(@NotNull Class<T> service, @Nullable ClassLoader loader, Component component) {
         return new ServiceFinder<T>(service, loader, component);
     }
     public static <T> ServiceFinder<T> find(@NotNull Class<T> service, Component component) {
         return find(service,Thread.currentThread().getContextClassLoader(),component);
     }
     /**
      * Locates and incrementally instantiates the available providers of a
      * given service using the given class loader.
      * <p/>
      * <p> This method transforms the name of the given service class into a
      * provider-configuration filename as described above and then uses the
      * <tt>getResources</tt> method of the given class loader to find all
      * available files with that name.  These files are then read and parsed to
      * produce a list of provider-class names.  The iterator that is returned
      * uses the given class loader to lookup and then instantiate each element
      * of the list.
      * <p/>
      * <p> Because it is possible for extensions to be installed into a running
      * Java virtual machine, this method may return different results each time
      * it is invoked. <p>
      *
      * @param service The service's abstract service class
      * @param loader  The class loader to be used to load provider-configuration files
      *                and instantiate provider classes, or <tt>null</tt> if the system
      *                class loader (or, failing that the bootstrap class loader) is to
      *                be used
      * @throws ServiceConfigurationError If a provider-configuration file violates the specified format
      *                                   or names a provider class that cannot be found and instantiated
      * @see #find(Class)
      */
     public static <T> ServiceFinder<T> find(@NotNull Class<T> service, @Nullable ClassLoader loader) {
         return find(service, loader, ContainerResolver.getInstance().getContainer());
     }
     /**
      * Locates and incrementally instantiates the available providers of a
      * given service using the context class loader.  This convenience method
      * is equivalent to
      * <p/>
      * <pre>
      *   ClassLoader cl = Thread.currentThread().getContextClassLoader();
      *   return Service.providers(service, cl);
      * </pre>
      *
      * @param service The service's abstract service class
      *
      * @throws ServiceConfigurationError If a provider-configuration file violates the specified format
      *                                   or names a provider class that cannot be found and instantiated
      * @see #find(Class, ClassLoader)
      */
     public static <T> ServiceFinder<T> find(Class<T> service) {
         return find(service,Thread.currentThread().getContextClassLoader());
     }
     private ServiceFinder(Class<T> service, ClassLoader loader, Component component) {
         this.serviceClass = service;
         this.classLoader = loader;
         this.component = getComponentEx(component);
     }
     private static ServiceName[] serviceClassNames(Class serviceClass, ClassLoader classLoader) {
         ArrayList<ServiceName> l = new ArrayList<ServiceName>();
         for (Iterator<ServiceName> it = new ServiceNameIterator(serviceClass,classLoader);it.hasNext();) l.add(it.next());
         return l.toArray(new ServiceName[l.size()]);
     }
     /**
      * Returns discovered objects incrementally.
      *
      * @return An <tt>Iterator</tt> that yields provider objects for the given
      *         service, in some arbitrary order.  The iterator will throw a
      *         <tt>ServiceConfigurationError</tt> if a provider-configuration
      *         file violates the specified format or if a provider class cannot
      *         be found and instantiated.
      */
     @SuppressWarnings("unchecked")
         public Iterator<T> iterator() {
         Iterator<T> it = new LazyIterator<T>(serviceClass,classLoader);
         return component != null ?
                         new CompositeIterator<T>(
                                         component.getIterableSPI(serviceClass).iterator(),it) :
                         it;
     }
     /**
      * Returns discovered objects all at once.
      *
      * @return
      *      can be empty but never null.
      *
      * @throws ServiceConfigurationError
      */
     public T[] toArray() {
         List<T> result = new ArrayList<T>();
         for (T t : this) {
             result.add(t);
         }
         return result.toArray((T[])Array.newInstance(serviceClass,result.size()));
     }
     private static void fail(Class service, String msg, Throwable cause)
         throws ServiceConfigurationError {
         ServiceConfigurationError sce
             = new ServiceConfigurationError(service.getName() + ": " + msg);
         sce.initCause(cause);
         throw sce;
     }
     private static void fail(Class service, String msg)
         throws ServiceConfigurationError {
         throw new ServiceConfigurationError(service.getName() + ": " + msg);
     }
     private static void fail(Class service, URL u, int line, String msg)
         throws ServiceConfigurationError {
         fail(service, u + ":" + line + ": " + msg);
     }
     /**
      * Parse a single line from the given configuration file, adding the name
      * on the line to both the names list and the returned set iff the name is
      * not already a member of the returned set.
      */
     private static int parseLine(Class service, URL u, BufferedReader r, int lc,
                                  List<String> names, Set<String> returned)
         throws IOException, ServiceConfigurationError {
         String ln = r.readLine();
         if (ln == null) {
             return -1;
         }
         int ci = ln.indexOf('#');
         if (ci >= 0) ln = ln.substring(0, ci);
         ln = ln.trim();
         int n = ln.length();
         if (n != 0) {
             if ((ln.indexOf(' ') >= 0) || (ln.indexOf('\t') >= 0))
                 fail(service, u, lc, "Illegal configuration-file syntax");
             int cp = ln.codePointAt(0);
             if (!Character.isJavaIdentifierStart(cp))
                 fail(service, u, lc, "Illegal provider-class name: " + ln);
             for (int i = Character.charCount(cp); i < n; i += Character.charCount(cp)) {
                 cp = ln.codePointAt(i);
                 if (!Character.isJavaIdentifierPart(cp) && (cp != '.'))
                     fail(service, u, lc, "Illegal provider-class name: " + ln);
             }
             if (!returned.contains(ln)) {
                 names.add(ln);
                 returned.add(ln);
             }
         }
         return lc + 1;
     }
     /**
      * Parse the content of the given URL as a provider-configuration file.
      *
      * @param service  The service class for which providers are being sought;
      *                 used to construct error detail strings
      * @param u        The URL naming the configuration file to be parsed
      * @param returned A Set containing the names of provider classes that have already
      *                 been returned.  This set will be updated to contain the names
      *                 that will be yielded from the returned <tt>Iterator</tt>.
      * @return A (possibly empty) <tt>Iterator</tt> that will yield the
      *         provider-class names in the given configuration file that are
      *         not yet members of the returned set
      * @throws ServiceConfigurationError If an I/O error occurs while reading from the given URL, or
      *                                   if a configuration-file format error is detected
      */
     @SuppressWarnings({"StatementWithEmptyBody"})
     private static Iterator<String> parse(Class service, URL u, Set<String> returned)
         throws ServiceConfigurationError {
         InputStream in = null;
         BufferedReader r = null;
         ArrayList<String> names = new ArrayList<String>();
         try {
             in = u.openStream();
             r = new BufferedReader(new InputStreamReader(in, "utf-8"));
             int lc = 1;
             while ((lc = parseLine(service, u, r, lc, names, returned)) >= 0) ;
         } catch (IOException x) {
             fail(service, ": " + x);
         } finally {
             try {
                 if (r != null) r.close();
                 if (in != null) in.close();
             } catch (IOException y) {
                 fail(service, ": " + y);
             }
         }
         return names.iterator();
     }
     private static ComponentEx getComponentEx(Component component) {
         if (component instanceof ComponentEx)
                 return (ComponentEx) component;
         return component != null ? new ComponentExWrapper(component) : null;
     }
     private static class ComponentExWrapper implements ComponentEx {
         private final Component component;
         public ComponentExWrapper(Component component) {
                 this.component = component;
         }
                 public <S> S getSPI(Class<S> spiType) {
                         return component.getSPI(spiType);
                 }
                 public <S> Iterable<S> getIterableSPI(Class<S> spiType) {
                 S item = getSPI(spiType);
                 if (item != null) {
                         Collection<S> c = Collections.singletonList(item);
                         return c;
                 }
                 return Collections.emptySet();
                 }
     }
     private static class CompositeIterator<T> implements Iterator<T> {
         private final Iterator<Iterator<T>> it;
         private Iterator<T> current = null;
         public CompositeIterator(Iterator<T>... iterators) {
                 it = Arrays.asList(iterators).iterator();
         }
                 public boolean hasNext() {
                         if (current != null && current.hasNext())
                                 return true;
                         while (it.hasNext()) {
                                 current = it.next();
                                 if (current.hasNext())
                                         return true;
                         }
                         return false;
                 }
                 public T next() {
                         if (!hasNext())
                                 throw new NoSuchElementException();
                         return current.next();
                 }
                 public void remove() {
             throw new UnsupportedOperationException();
                 }
     }
     /**
      * Private inner class implementing fully-lazy provider lookup
      */
     private static class ServiceNameIterator implements Iterator<ServiceName> {
         Class service;
         @Nullable ClassLoader loader;
         Enumeration<URL> configs = null;
         Iterator<String> pending = null;
         Set<String> returned = new TreeSet<String>();
         String nextName = null;
         URL currentConfig = null;
         private ServiceNameIterator(Class service, ClassLoader loader) {
             this.service = service;
             this.loader = loader;
         }
         public boolean hasNext() throws ServiceConfigurationError {
             if (nextName != null) {
                 return true;
             }
             if (configs == null) {
                 try {
                     String fullName = prefix + service.getName();
                     if (loader == null)
                         configs = ClassLoader.getSystemResources(fullName);
                     else
                         configs = loader.getResources(fullName);
                 } catch (IOException x) {
                     fail(service, ": " + x);
                 }
             }
             while ((pending == null) || !pending.hasNext()) {
                 if (!configs.hasMoreElements()) {
                     return false;
                 }
                 currentConfig = configs.nextElement();
                 pending = parse(service, currentConfig, returned);
             }
             nextName = pending.next();
             return true;
         }
         public ServiceName next() throws ServiceConfigurationError {
             if (!hasNext()) {
                 throw new NoSuchElementException();
             }
             String cn = nextName;
             nextName = null;
             return new ServiceName(cn, currentConfig);
         }
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
     private static class LazyIterator<T> implements Iterator<T> {
         Class<T> service;
         @Nullable ClassLoader loader;
         ServiceName[] names;
         int index;
         private LazyIterator(Class<T> service, ClassLoader loader) {
             this.service = service;
             this.loader = loader;
             this.names = null;
             index = 0;
         }
         @Override
         public boolean hasNext() {
             if (names == null) {
                 ConcurrentHashMap<String, ServiceName[]> nameMap = null;
                 synchronized(serviceNameCache){ nameMap = serviceNameCache.get(loader); }
                 names = (nameMap != null)? nameMap.get(service.getName()) : null;
                 if (names == null) {
                     names = serviceClassNames(service, loader);
                     if (nameMap == null) nameMap = new ConcurrentHashMap<String, ServiceName[]>();
                     nameMap.put(service.getName(), names);
                     synchronized(serviceNameCache){ serviceNameCache.put(loader,nameMap); }
                 }
             }
             return (index < names.length);
         }
         @Override
         public T next() {
             if (!hasNext()) throw new NoSuchElementException();
             ServiceName sn = names[index++];
             String cn = sn.className;
             URL currentConfig = sn.config;
             try {
                 return service.cast(Class.forName(cn, true, loader).newInstance());
             } catch (ClassNotFoundException x) {
                 fail(service, "Provider " + cn + " is specified in "+currentConfig+" but not found");
             } catch (Exception x) {
               fail(service, "Provider " + cn + " is specified in "+currentConfig+"but could not be instantiated: " + x, x);
             }
             return null;    /* This cannot happen */
         }
         @Override
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
 }

Mercurial > jdk8-mips64-public > jaxws / annotate

src/share/jaxws_classes/com/sun/xml/internal/ws/util/ServiceFinder.java@9c07ef4934dd (annotated)

src/share/jaxws_classes/com/sun/xml/internal/ws/util/ServiceFinder.java