This is an automated email from the ASF dual-hosted git repository.
desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
commit bbd71a4c2281e2feae6b4c2a456ef8d1d027dd2b
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Sat Jun 10 17:42:00 2023 +0200
Remove the use of internal `LazySet` as a workaround for JDK 8 bug in
`java.util.ServiceLoader` since this workaround is no longer necessary.
Remove usage of `ServiceLoader` in `LazySet` since it does not work anymore
in JPMS context. Services shall be loaded in the caller class.
---
.../apache/sis/internal/referencing/LazySet.java | 93 +++++++---------------
.../apache/sis/referencing/AuthorityFactories.java | 16 +++-
.../transform/DefaultMathTransformFactory.java | 25 +-----
.../sis/internal/referencing/LazySetTest.java | 8 +-
.../referencing/provider/ProvidersTest.java | 2 +-
.../transform/DefaultMathTransformFactoryTest.java | 21 +++++
.../org/apache/sis/internal/netcdf/Convention.java | 8 +-
.../org/apache/sis/storage/DataStoreRegistry.java | 60 +++++++-------
.../java/org/apache/sis/storage/DataStores.java | 54 ++-----------
.../org/apache/sis/storage/DataStoresTest.java | 6 +-
10 files changed, 121 insertions(+), 172 deletions(-)
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/LazySet.java
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/LazySet.java
index e70e9da650..c4cb25425f 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/LazySet.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/LazySet.java
@@ -16,46 +16,32 @@
*/
package org.apache.sis.internal.referencing;
-import java.util.List;
import java.util.Arrays;
-import java.util.Objects;
import java.util.Iterator;
-import java.util.ServiceLoader;
import java.util.NoSuchElementException;
-import org.apache.sis.internal.system.Reflect;
import org.apache.sis.internal.util.SetOfUnknownSize;
-import org.apache.sis.internal.util.UnmodifiableArrayList;
/**
- * An immutable set built from an iterator, which will be filled only when
needed.
+ * An unmodifiable set built from an iterator, which will be filled only when
needed.
* This implementation does <strong>not</strong> check if all elements in the
iterator
* are really unique; we assume that this condition was already verified by
the caller.
*
- * <p>One usage of {@code LazySet} is to workaround a {@link
java.util.ServiceLoader} bug which blocks usage of two
- * {@link Iterator} instances together: the first iteration must be fully
completed or abandoned before we can start
- * a new iteration. See
- * {@link
org.apache.sis.referencing.operation.transform.DefaultMathTransformFactory#DefaultMathTransformFactory()}.</p>
- *
* <p>Some usages for this class are to prepend some values before the
elements given by the source {@code Iterable},
* or to replace some values when they are loaded. It may also be used for
creating filtered sets when used together
* with {@link org.apache.sis.internal.util.CollectionsExt#filter
CollectionsExt.filter(…)}.</p>
*
- * <p>This class is not thread-safe. Synchronization, if desired, shall be
done by the caller.</p>
+ * <h2>Thread-safety</h2>
+ * This class is thread safe. The synchronization lock is {@code this}.
*
* @author Martin Desruisseaux (IRD, Geomatys)
- * @version 0.8
+ * @version 1.4
*
* @param <E> the type of elements in the set.
*
* @since 0.6
*/
-public class LazySet<E> extends SetOfUnknownSize<E> {
- /**
- * The type of service to request with {@link ServiceLoader}, or {@code
null} if unknown.
- */
- private final Class<E> service;
-
+public abstract class LazySet<E> extends SetOfUnknownSize<E> {
/**
* The iterator to use for filling this set, or {@code null} if the
iteration did not started yet or is finished.
* Those two cases can be distinguished by looking whether the {@link
#cachedElements} array is null or not.
@@ -78,39 +64,19 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
private int numCached;
/**
- * Constructs a set to be filled by the elements from the specified
source. Iteration will start only when
- * first needed, and at most one iteration will be performed (unless
{@link #reload()} is invoked).
- *
- * @param service the type of service to request with {@link
ServiceLoader}.
+ * Creates a new set.
*/
- public LazySet(final Class<E> service) {
- Objects.requireNonNull(service);
- this.service = service;
+ protected LazySet() {
}
/**
- * Constructs a set to be filled using the specified iterator.
- * Iteration with the given iterator will occur only when needed.
+ * Creates the iterator which will provide the elements of this set before
filtering.
+ * This method will be invoked only when first needed and at most once,
unless {@link #reload()} is invoked.
+ * After creation, calls to {@link Iterator#next()} will also be done only
when first needed.
*
- * @param iterator the iterator to use for filling this set.
+ * @return iterator over the elements of this set before filtering.
*/
- public LazySet(final Iterator<? extends E> iterator) {
- Objects.requireNonNull(iterator);
- sourceIterator = iterator;
- service = null;
- createCache();
- }
-
- /**
- * Notifies this {@code LazySet} that it should re-fetch the elements from
the source given at construction time.
- */
- public void reload() {
- if (service != null) {
- sourceIterator = null;
- cachedElements = null;
- numCached = 0;
- }
- }
+ protected abstract Iterator<? extends E> createSourceIterator();
/**
* Hook for subclasses that want to prepend some values before the source
{@code Iterable}.
@@ -151,7 +117,7 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
*/
private boolean canPullMore() {
if (sourceIterator == null && cachedElements == null) {
- sourceIterator = ServiceLoader.load(service,
Reflect.getContextClassLoader()).iterator();
+ sourceIterator = createSourceIterator();
if (createCache()) {
return true;
}
@@ -171,7 +137,7 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
* @return {@code true} if this set has no element.
*/
@Override
- public final boolean isEmpty() {
+ public final synchronized boolean isEmpty() {
return (numCached == 0) && !canPullMore();
}
@@ -182,7 +148,7 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
* @return number of elements in the iterator.
*/
@Override
- public final int size() {
+ public final synchronized int size() {
if (canPullMore()) {
while (sourceIterator.hasNext()) {
cache(next(sourceIterator));
@@ -206,12 +172,12 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
}
/**
- * Caches a new element. Subclasses can override this method if they want
to substitute the given value
- * by another value.
+ * Caches a new element. This method is invoked by {@code LazySet} inside
a synchronized block.
+ * Subclasses could override this method if they want to substitute the
given value by another value.
*
* @param element the element to add to the cache.
*/
- protected void cache(final E element) {
+ private void cache(final E element) {
if (cachedElements == null) {
createCache();
}
@@ -221,16 +187,6 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
cachedElements[numCached++] = element;
}
- /**
- * Returns an unmodifiable view over the elements cached so far.
- * The returned list does not contain any elements that were not yet
fetched from the source.
- *
- * @return the elements cached so far.
- */
- protected final List<E> cached() {
- return UnmodifiableArrayList.wrap(cachedElements, 0, numCached);
- }
-
/**
* Returns {@code true} if an element exists at the given index.
* The element is not loaded immediately.
@@ -239,7 +195,7 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
* It is not suited for more general usage since it does not check for
* negative index and for skipped elements.</p>
*/
- final boolean exists(final int index) {
+ private synchronized boolean exists(final int index) {
assert index <= numCached : index;
return (index < numCached) || canPullMore();
}
@@ -250,7 +206,7 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
* @param index the index at which to get an element.
* @return the element at the requested index.
*/
- final E get(final int index) {
+ private synchronized E get(final int index) {
assert numCached <= cachedElements.length : numCached;
assert index <= numCached : index;
if (index >= numCached) {
@@ -285,4 +241,13 @@ public class LazySet<E> extends SetOfUnknownSize<E> {
}
};
}
+
+ /**
+ * Notifies this {@code LazySet} that it should re-fetch the elements from
the source.
+ */
+ public synchronized void reload() {
+ sourceIterator = null;
+ cachedElements = null;
+ numCached = 0;
+ }
}
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/AuthorityFactories.java
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/AuthorityFactories.java
index 1d67cf0fb9..04474329da 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/AuthorityFactories.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/AuthorityFactories.java
@@ -29,6 +29,7 @@ import org.opengis.referencing.crs.CRSAuthorityFactory;
import org.opengis.referencing.datum.DatumAuthorityFactory;
import org.opengis.referencing.operation.CoordinateOperationAuthorityFactory;
import org.apache.sis.internal.referencing.LazySet;
+import org.apache.sis.internal.system.Reflect;
import org.apache.sis.internal.system.Loggers;
import org.apache.sis.internal.system.Modules;
import org.apache.sis.internal.system.SystemListener;
@@ -95,11 +96,24 @@ final class AuthorityFactories<T extends AuthorityFactory>
extends LazySet<T> {
});
}
+ /**
+ * The type of service to request with {@link ServiceLoader}, or {@code
null} if unknown.
+ */
+ private final Class<T> service;
+
/**
* Creates a new provider for factories of the given type.
*/
private AuthorityFactories(final Class<T> type) {
- super(type);
+ service = type;
+ }
+
+ /**
+ * Creates the iterator which will provide the elements of this set before
filtering.
+ */
+ @Override
+ protected Iterator<? extends T> createSourceIterator() {
+ return ServiceLoader.load(service,
Reflect.getContextClassLoader()).iterator();
}
/**
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactory.java
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactory.java
index 7c062b2ff2..783eca7656 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactory.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactory.java
@@ -57,7 +57,6 @@ import org.apache.sis.io.wkt.Parser;
import org.apache.sis.internal.util.URLs;
import org.apache.sis.internal.util.Strings;
import org.apache.sis.internal.util.Constants;
-import org.apache.sis.internal.referencing.LazySet;
import org.apache.sis.internal.referencing.Formulas;
import org.apache.sis.internal.referencing.CoordinateOperations;
import org.apache.sis.internal.referencing.ReferencingUtilities;
@@ -67,6 +66,7 @@ import
org.apache.sis.internal.referencing.provider.VerticalOffset;
import org.apache.sis.internal.referencing.provider.GeographicToGeocentric;
import org.apache.sis.internal.referencing.provider.GeocentricToGeographic;
import org.apache.sis.internal.referencing.Resources;
+import org.apache.sis.internal.system.Reflect;
import org.apache.sis.metadata.iso.citation.Citations;
import org.apache.sis.parameter.DefaultParameterValueGroup;
import org.apache.sis.parameter.Parameterized;
@@ -282,25 +282,7 @@ public class DefaultMathTransformFactory extends
AbstractFactory implements Math
* @see #reload()
*/
public DefaultMathTransformFactory() {
- /*
- * WORKAROUND for a JDK bug: ServiceLoader does not support usage of
two Iterator instances
- * before the first iteration is finished. Steps to reproduce:
- *
- * ServiceLoader<?> loader =
ServiceLoader.load(OperationMethod.class);
- *
- * Iterator<?> it1 = loader.iterator();
- * assertTrue ( it1.hasNext() );
- * assertNotNull( it1.next()) );
- *
- * Iterator<?> it2 = loader.iterator();
- * assertTrue ( it1.hasNext()) );
- * assertTrue ( it2.hasNext()) );
- * assertNotNull( it1.next()) );
- * assertNotNull( it2.next()) ); //
ConcurrentModificationException here !!!
- *
- * Wrapping the ServiceLoader in a LazySet avoid this issue.
- */
- this(new LazySet<OperationMethod>(OperationMethod.class));
+ this(ServiceLoader.load(OperationMethod.class,
Reflect.getContextClassLoader()));
}
/**
@@ -1771,9 +1753,6 @@ public class DefaultMathTransformFactory extends
AbstractFactory implements Math
synchronized (methods) {
methodsByName.clear();
final Iterable<? extends OperationMethod> m = methods;
- if (m instanceof LazySet<?>) { // Workaround for JDK bug. See
DefaultMathTransformFactory() constructor.
- ((LazySet<? extends OperationMethod>) m).reload();
- }
if (m instanceof ServiceLoader<?>) {
((ServiceLoader<?>) m).reload();
}
diff --git
a/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/LazySetTest.java
b/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/LazySetTest.java
index c28651963e..73388691b2 100644
---
a/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/LazySetTest.java
+++
b/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/LazySetTest.java
@@ -29,7 +29,7 @@ import static org.junit.Assert.*;
* Tests {@link LazySet}
*
* @author Martin Desruisseaux (Geomatys)
- * @version 0.6
+ * @version 1.4
* @since 0.6
*/
public final class LazySetTest extends TestCase {
@@ -42,7 +42,11 @@ public final class LazySetTest extends TestCase {
* Creates the set to use for testing purpose.
*/
private static LazySet<String> create() {
- return new LazySet<>(Arrays.asList(LABELS).iterator());
+ return new LazySet<>() {
+ @Override protected Iterator<String> createSourceIterator() {
+ return Arrays.asList(LABELS).iterator();
+ }
+ };
}
/**
diff --git
a/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/provider/ProvidersTest.java
b/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/provider/ProvidersTest.java
index a775c0601a..14cac2b1b5 100644
---
a/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/provider/ProvidersTest.java
+++
b/core/sis-referencing/src/test/java/org/apache/sis/internal/referencing/provider/ProvidersTest.java
@@ -33,7 +33,7 @@ import static org.junit.Assert.*;
/**
- * Tests {@link Providers} and some consistency rules of all providers defined
in this package.
+ * Tests some consistency rules of all providers defined in this package.
*
* @author Martin Desruisseaux (Geomatys)
* @version 1.4
diff --git
a/core/sis-referencing/src/test/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactoryTest.java
b/core/sis-referencing/src/test/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactoryTest.java
index 4d90d2b28d..367fe18a94 100644
---
a/core/sis-referencing/src/test/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactoryTest.java
+++
b/core/sis-referencing/src/test/java/org/apache/sis/referencing/operation/transform/DefaultMathTransformFactoryTest.java
@@ -19,6 +19,7 @@ package org.apache.sis.referencing.operation.transform;
import java.util.Map;
import java.util.Set;
import java.util.Collection;
+import java.util.Iterator;
import java.util.ServiceLoader;
import org.opengis.util.FactoryException;
import org.opengis.util.NoSuchIdentifierException;
@@ -89,6 +90,26 @@ public final class DefaultMathTransformFactoryTest extends
TestCase {
assertSame(factory(), factory);
}
+ /**
+ * Tests the correction for a Java 8 bug. In Java 8, {@link ServiceLoader}
didn't supported
+ * the usage of two {@link Iterator} instances before the first iteration
is finished.
+ * This problem has been fixed with Java Platform Module System (JPMS)
implementation.
+ */
+ @Test
+ public void testServiceLoaderIterator() {
+ ServiceLoader<?> loader = ServiceLoader.load(OperationMethod.class);
+
+ Iterator<?> it1 = loader.iterator();
+ assertTrue (it1.hasNext());
+ assertNotNull(it1.next());
+
+ Iterator<?> it2 = loader.iterator();
+ assertTrue (it1.hasNext());
+ assertTrue (it2.hasNext());
+ assertNotNull(it1.next());
+ assertNotNull(it2.next()); // ConcurrentModificationException was
used to be thownn here.
+ }
+
/**
* Tests the {@link
DefaultMathTransformFactory#getOperationMethod(String)} method.
*
diff --git
a/storage/sis-netcdf/src/main/java/org/apache/sis/internal/netcdf/Convention.java
b/storage/sis-netcdf/src/main/java/org/apache/sis/internal/netcdf/Convention.java
index 72cdc7cd69..d165729949 100644
---
a/storage/sis-netcdf/src/main/java/org/apache/sis/internal/netcdf/Convention.java
+++
b/storage/sis-netcdf/src/main/java/org/apache/sis/internal/netcdf/Convention.java
@@ -22,6 +22,7 @@ import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Locale;
+import java.util.ServiceLoader;
import java.util.function.Function;
import java.awt.Color;
import javax.measure.Unit;
@@ -33,8 +34,8 @@ import org.opengis.referencing.operation.TransformException;
import org.apache.sis.referencing.operation.transform.TransferFunction;
import org.apache.sis.referencing.datum.BursaWolfParameters;
import org.apache.sis.referencing.CommonCRS;
-import org.apache.sis.internal.referencing.LazySet;
import org.apache.sis.internal.coverage.j2d.ColorModelFactory;
+import org.apache.sis.internal.system.Reflect;
import org.apache.sis.measure.MeasurementRange;
import org.apache.sis.measure.NumberRange;
import org.apache.sis.coverage.Category;
@@ -67,7 +68,7 @@ import ucar.nc2.constants.CF;
* @author Johann Sorel (Geomatys)
* @author Martin Desruisseaux (Geomatys)
* @author Alexis Manin (Geomatys)
- * @version 1.3
+ * @version 1.4
*
* @see <a href="https://issues.apache.org/jira/browse/SIS-315";>SIS-315</a>
*
@@ -77,7 +78,8 @@ public class Convention {
/**
* All conventions found on the classpath.
*/
- private static final LazySet<Convention> AVAILABLES = new
LazySet<>(Convention.class);
+ private static final ServiceLoader<Convention> AVAILABLES =
+ ServiceLoader.load(Convention.class,
Reflect.getContextClassLoader());
/**
* The convention to use when no specific conventions were found.
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreRegistry.java
b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreRegistry.java
index 2290c9ad63..515cc89c49 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreRegistry.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreRegistry.java
@@ -18,10 +18,11 @@ package org.apache.sis.storage;
import java.util.List;
import java.util.LinkedList;
-import java.util.Set;
import java.util.Iterator;
import java.util.ServiceLoader;
import org.apache.sis.internal.system.Reflect;
+import org.apache.sis.internal.system.Modules;
+import org.apache.sis.internal.system.SystemListener;
import org.apache.sis.internal.storage.Resources;
import org.apache.sis.internal.storage.StoreMetadata;
import org.apache.sis.internal.referencing.LazySet;
@@ -31,12 +32,8 @@ import org.apache.sis.util.ArraysExt;
/**
* Creates {@link DataStore} instances for a given storage object by scanning
all providers on the classpath.
- * Storage objects are typically {@link java.io.File} or {@link
javax.sql.DataSource} instances, but can also
- * be any other objects documented in the {@link StorageConnector} class.
- *
- * <h2>API note</h2>
- * This class is package-private for now in order to get more experience about
what could be a good API.
- * This class may become public in a future SIS version.
+ * Storage objects are typically {@link java.io.File} or {@link
javax.sql.DataSource} instances,
+ * but can also be any other objects documented in the {@link
StorageConnector} class.
*
* <h2>Thread safety</h2>
* The same {@code DataStoreRegistry} instance can be safely used by many
threads without synchronization
@@ -46,7 +43,19 @@ import org.apache.sis.util.ArraysExt;
* @version 1.4
* @since 0.4
*/
-final class DataStoreRegistry {
+final class DataStoreRegistry extends LazySet<DataStoreProvider> {
+ /**
+ * The unique instance of this registry.
+ */
+ static final DataStoreRegistry INSTANCE = new DataStoreRegistry();
+ static {
+ SystemListener.add(new SystemListener(Modules.STORAGE) {
+ @Override protected void classpathChanged() {
+ INSTANCE.reload();
+ }
+ });
+ }
+
/**
* The loader to use for searching for {@link DataStoreProvider}
implementations.
* Note that {@code ServiceLoader} are not thread-safe - usage of this
field must
@@ -60,31 +69,17 @@ final class DataStoreRegistry {
* provided that it can access at least the Apache SIS stores.
*/
public DataStoreRegistry() {
- this(Reflect.getContextClassLoader());
+ this.loader = ServiceLoader.load(DataStoreProvider.class,
Reflect.getContextClassLoader());
}
/**
- * Creates a new registry which will look for data stores accessible to
the given class loader.
- *
- * @param loader the class loader to use for loading {@link
DataStoreProvider} implementations.
+ * Creates the iterator over the data stores.
*/
- public DataStoreRegistry(final ClassLoader loader) {
- ArgumentChecks.ensureNonNull("loader", loader);
- this.loader = ServiceLoader.load(DataStoreProvider.class, loader);
- }
-
- /**
- * Returns the list of data store providers available at this method
invocation time.
- * More providers may be added later if new modules are added on the
classpath.
- *
- * @return descriptions of available data stores.
- *
- * @since 0.8
- */
- public Set<DataStoreProvider> providers() {
+ @Override
+ protected Iterator<DataStoreProvider> createSourceIterator() {
synchronized (loader) {
final Iterator<DataStoreProvider> providers = loader.iterator();
- return new LazySet<>(new Iterator<DataStoreProvider>() {
+ return new Iterator<DataStoreProvider>() {
@Override public boolean hasNext() {
synchronized (loader) {
return providers.hasNext();
@@ -96,7 +91,7 @@ final class DataStoreRegistry {
return providers.next();
}
}
- });
+ };
}
}
@@ -317,4 +312,13 @@ search: for (int ci=0; ci < categories.length; ci++) {
}
return selected;
}
+
+ /**
+ * Notifies this registry that it should re-fetch the elements from the
source.
+ */
+ @Override
+ public synchronized void reload() {
+ loader.reload();
+ super.reload();
+ }
}
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStores.java
b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStores.java
index 05718f99bc..c93587226f 100644
--- a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStores.java
+++ b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStores.java
@@ -18,8 +18,6 @@ package org.apache.sis.storage;
import java.util.Collection;
import org.apache.sis.util.Static;
-import org.apache.sis.internal.system.Modules;
-import org.apache.sis.internal.system.SystemListener;
/**
@@ -29,33 +27,10 @@ import org.apache.sis.internal.system.SystemListener;
*
* @author Martin Desruisseaux (Geomatys)
* @author Johann Sorel (Geomatys)
- * @version 1.0
+ * @version 1.4
* @since 0.4
*/
public final class DataStores extends Static {
- /**
- * The registry to use for searching for {@link DataStoreProvider}
implementations.
- *
- * <h4>Class loader</h4>
- * In current implementation, this registry is instantiated when first
needed using the
- * {@linkplain Thread#getContextClassLoader() context class loader}. This
means that the set of
- * available formats may depend on the first thread that invoked a {@code
DataStores} method.
- */
- private static volatile DataStoreRegistry registry;
-
- /*
- * Forces a reload of all providers when the classpath changes. Note that
invoking
- * ServiceLoader.reload() is not sufficient because the ClassLoader may
also change
- * in OSGi context.
- */
- static {
- SystemListener.add(new SystemListener(Modules.STORAGE) {
- @Override protected void classpathChanged() {
- registry = null;
- }
- });
- }
-
/**
* Do not allow instantiation of this class.
*/
@@ -63,31 +38,16 @@ public final class DataStores extends Static {
}
/**
- * Returns the registry, created when first needed.
- */
- private static DataStoreRegistry registry() {
- DataStoreRegistry r = registry;
- if (r == null) {
- synchronized (DataStores.class) {
- r = registry;
- if (r == null) {
- registry = r = new DataStoreRegistry();
- }
- }
- }
- return r;
- }
-
- /**
- * Returns the set of data store providers available at this method
invocation time.
- * More providers may be added later in a running JVM if new modules are
added on the classpath.
+ * Returns the set of available data store providers.
+ * The returned collection is live: its content may change
+ * if new modules are added on the classpath at run-time.
*
* @return descriptions of available data stores.
*
* @since 0.8
*/
public static Collection<DataStoreProvider> providers() {
- return registry().providers();
+ return DataStoreRegistry.INSTANCE;
}
/**
@@ -98,7 +58,7 @@ public final class DataStores extends Static {
* @throws DataStoreException if an error occurred while opening the
storage.
*/
public static String probeContentType(final Object storage) throws
DataStoreException {
- return registry().probeContentType(storage);
+ return DataStoreRegistry.INSTANCE.probeContentType(storage);
}
/**
@@ -121,6 +81,6 @@ public final class DataStores extends Static {
* @throws DataStoreException if an error occurred while opening the
storage.
*/
public static DataStore open(final Object storage) throws
UnsupportedStorageException, DataStoreException {
- return registry().open(storage);
+ return DataStoreRegistry.INSTANCE.open(storage);
}
}
diff --git
a/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoresTest.java
b/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoresTest.java
index 237a0de900..cad22e13db 100644
---
a/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoresTest.java
+++
b/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoresTest.java
@@ -41,7 +41,7 @@ import static org.apache.sis.test.Assertions.assertSetEquals;
*
* @author Martin Desruisseaux (Geomatys)
* @author Alexis Manin (Geomatys)
- * @version 1.1
+ * @version 1.4
* @since 0.4
*/
@DependsOn(StoreTest.class)
@@ -105,12 +105,12 @@ public final class DataStoresTest extends TestCase {
private static List<Set<Class<?>>> collectProvidersConcurrently(final int
nbWorkers, final ExecutorService executor)
throws Exception
{
- final DataStoreRegistry dsr = new
DataStoreRegistry(DataStoresTest.class.getClassLoader());
+ final DataStoreRegistry dsr = DataStoreRegistry.INSTANCE;
final CyclicBarrier startSignal = new CyclicBarrier(nbWorkers);
final Callable<Set<Class<?>>> collectProviderClasses = () -> {
final Set<Class<?>> result = new HashSet<>();
startSignal.await(10, TimeUnit.SECONDS); //
Wait until all workers are ready.
- for (DataStoreProvider p : dsr.providers()) { //
This is the iteration to test.
+ for (DataStoreProvider p : dsr) { //
This is the iteration to test.
result.add(p.getClass());
}
return result;
