Bug 422026 - Get rid of ColletionUtils.empty[Set|List|Map]

Now that p2 has Java 1.5 as a minimum there is no reason to not use the
JVM methods.

Change-Id: I89444e8d1e174c316e2b17fb4f53bc7b1d097c0a
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>

13 files changed, 17 insertions, 30 deletions

diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/IUMap.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/IUMap.java
index 674387912..bc2f95c30 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/IUMap.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/IUMap.java
@@ -162,7 +162,7 @@ public class IUMap implements Cloneable {
 	public Collection<IInstallableUnit> getUnits(String id) {
 		Object bucket = units.get(id);
 		if (bucket == null)
-			return CollectionUtils.emptyList();
+			return Collections.<IInstallableUnit> emptyList();
 		return bucket.getClass().isArray() ? CollectionUtils.unmodifiableList((IInstallableUnit[]) bucket) : Collections.<IInstallableUnit> singletonList((IInstallableUnit) bucket);
 	}
 
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/InstallableUnit.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/InstallableUnit.java
index 8248f16a9..48dcf2344 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/InstallableUnit.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/InstallableUnit.java
@@ -131,7 +131,7 @@ public class InstallableUnit implements IInstallableUnit, IMemberProvider {
 	}
 
 	public Collection<IInstallableUnitFragment> getFragments() {
-		return CollectionUtils.emptyList();
+		return Collections.<IInstallableUnitFragment> emptyList();
 	}
 
 	public String getId() {
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/ResolvedInstallableUnit.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/ResolvedInstallableUnit.java
index f9d98b4f9..7e036b69e 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/ResolvedInstallableUnit.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/ResolvedInstallableUnit.java
@@ -12,7 +12,6 @@
 package org.eclipse.equinox.internal.p2.metadata;
 
 import java.util.*;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.p2.metadata.*;
 import org.eclipse.equinox.p2.metadata.expression.IMatchExpression;
 import org.eclipse.equinox.p2.metadata.expression.IMemberProvider;
@@ -38,7 +37,7 @@ public class ResolvedInstallableUnit implements IInstallableUnit, IMemberProvide
 	public Collection<IInstallableUnitFragment> getFragments() {
 		int fcount = fragments.length;
 		if (fcount == 0)
-			return CollectionUtils.emptyList();
+			return Collections.<IInstallableUnitFragment> emptyList();
 
 		ArrayList<IInstallableUnitFragment> result = new ArrayList<IInstallableUnitFragment>(fcount);
 		result.addAll(Arrays.asList(fragments));
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Everything.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Everything.java
index 52758ad32..4cc51cff9 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Everything.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Everything.java
@@ -10,9 +10,7 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.metadata.expression;
 
-import java.util.Collection;
-import java.util.Iterator;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
+import java.util.*;
 import org.eclipse.equinox.p2.metadata.index.IIndexProvider;
 
 /**
@@ -24,7 +22,7 @@ public final class Everything<T> extends MatchIteratorFilter<T> implements IRepe
 	private final Class<? extends T> elementClass;
 
 	public Everything(Class<? extends T> elementClass, Collection<T> collection) {
-		super(RepeatableIterator.<T> create(collection == null ? CollectionUtils.<T> emptyList() : collection));
+		super(RepeatableIterator.<T> create(collection == null ? Collections.<T> emptyList() : collection));
 		this.elementClass = elementClass;
 	}
 
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Expression.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Expression.java
index 9cdbd5226..7966215ae 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Expression.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Expression.java
@@ -11,7 +11,6 @@
 package org.eclipse.equinox.internal.p2.metadata.expression;
 
 import java.util.*;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.internal.p2.metadata.InstallableUnit;
 import org.eclipse.equinox.p2.metadata.IInstallableUnit;
 import org.eclipse.equinox.p2.metadata.expression.*;
@@ -342,7 +341,7 @@ public abstract class Expression implements IExpression, Comparable<Expression>,
 		}
 
 		List<String> getMembers() {
-			return members == null ? CollectionUtils.<String> emptyList() : members;
+			return members == null ? Collections.<String> emptyList() : members;
 		}
 	}
 
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Limit.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Limit.java
index 8a02b0e8a..5a5a1e5f2 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Limit.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Limit.java
@@ -10,9 +10,7 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.metadata.expression;
 
-import java.util.Iterator;
-import java.util.NoSuchElementException;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
+import java.util.*;
 import org.eclipse.equinox.p2.metadata.expression.IEvaluationContext;
 
 /**
@@ -68,7 +66,7 @@ final class Limit extends Binary {
 			limit = ((Integer) rval).intValue();
 		if (limit < 0)
 			throw new IllegalArgumentException("limit expression did not evalutate to a positive integer"); //$NON-NLS-1$
-		return limit == 0 ? CollectionUtils.emptySet().iterator() : new CountingIterator<Object>(lhs.evaluateAsIterator(context), limit);
+		return limit == 0 ? Collections.emptySet().iterator() : new CountingIterator<Object>(lhs.evaluateAsIterator(context), limit);
 	}
 
 	public int getExpressionType() {
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/MemberProvider.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/MemberProvider.java
index cc82db7d9..dccb00397 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/MemberProvider.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/MemberProvider.java
@@ -12,7 +12,6 @@ package org.eclipse.equinox.internal.p2.metadata.expression;
 
 import java.util.*;
 import java.util.Map.Entry;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.p2.metadata.expression.IMemberProvider;
 import org.osgi.framework.ServiceReference;
 
@@ -119,7 +118,7 @@ public abstract class MemberProvider implements IMemberProvider {
 		}
 	}
 
-	private static final MemberProvider emptyProvider = create(CollectionUtils.emptyMap(), false);
+	private static final MemberProvider emptyProvider = create(Collections.emptyMap(), false);
 
 	/**
 	 * Create a new member provider on the given value. The value can be an instance of a {@link Map}, {@link Dictionary},
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CapabilityIndex.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CapabilityIndex.java
index c9e2056f6..a30d1f530 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CapabilityIndex.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CapabilityIndex.java
@@ -11,7 +11,6 @@
 package org.eclipse.equinox.internal.p2.metadata.index;
 
 import java.util.*;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.internal.p2.metadata.*;
 import org.eclipse.equinox.internal.p2.metadata.expression.*;
 import org.eclipse.equinox.p2.metadata.*;
@@ -200,7 +199,7 @@ public class CapabilityIndex extends Index<IInstallableUnit> {
 		if (queriedKeys == Boolean.FALSE) {
 			// It has been determined that the expression has no chance
 			// to succeed regardless of input
-			matchingIUs = CollectionUtils.<IInstallableUnit> emptySet();
+			matchingIUs = Collections.<IInstallableUnit> emptySet();
 		} else if (queriedKeys instanceof Collection<?>) {
 			matchingIUs = new HashSet<IInstallableUnit>();
 			for (Object key : (Collection<Object>) queriedKeys)
@@ -208,7 +207,7 @@ public class CapabilityIndex extends Index<IInstallableUnit> {
 		} else {
 			Object v = capabilityMap.get(queriedKeys);
 			if (v == null)
-				matchingIUs = CollectionUtils.<IInstallableUnit> emptySet();
+				matchingIUs = Collections.<IInstallableUnit> emptySet();
 			else if (v instanceof IInstallableUnit)
 				matchingIUs = Collections.singleton((IInstallableUnit) v);
 			else
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CompoundIndex.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CompoundIndex.java
index 77e207f23..3caa03025 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CompoundIndex.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/index/CompoundIndex.java
@@ -11,7 +11,6 @@
 package org.eclipse.equinox.internal.p2.metadata.index;
 
 import java.util.*;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.p2.metadata.expression.IEvaluationContext;
 import org.eclipse.equinox.p2.metadata.expression.IExpression;
 import org.eclipse.equinox.p2.metadata.index.IIndex;
@@ -39,7 +38,7 @@ public class CompoundIndex<T> implements IIndex<T> {
 			}
 		}
 		if (result == null)
-			result = CollectionUtils.emptySet();
+			result = Collections.emptySet();
 		return result.iterator();
 	}
 }
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/metadata/MetadataFactory.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/metadata/MetadataFactory.java
index cd7227621..4cbaffb30 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/metadata/MetadataFactory.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/metadata/MetadataFactory.java
@@ -15,7 +15,6 @@ package org.eclipse.equinox.p2.metadata;
 import java.net.URI;
 import java.util.*;
 import org.eclipse.core.runtime.Assert;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.internal.p2.metadata.*;
 import org.eclipse.equinox.p2.metadata.expression.*;
 
@@ -374,7 +373,7 @@ public final class MetadataFactory {
 	/**
 	 * Singleton touchpoint data for a touchpoint with no instructions.
 	 */
-	private static final ITouchpointData EMPTY_TOUCHPOINT_DATA = new TouchpointData(CollectionUtils.<String, ITouchpointInstruction> emptyMap());
+	private static final ITouchpointData EMPTY_TOUCHPOINT_DATA = new TouchpointData(Collections.<String, ITouchpointInstruction> emptyMap());
 
 	private static ITouchpointType[] typeCache = new ITouchpointType[5];
 
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CollectionResult.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CollectionResult.java
index ef482853e..797483ecf 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CollectionResult.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CollectionResult.java
@@ -13,7 +13,6 @@ package org.eclipse.equinox.p2.query;
 import java.lang.reflect.Array;
 import java.util.*;
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 
 /**
  * This class allows to adapt java collections to a p2 a query result  and as such something queryable  
@@ -23,7 +22,7 @@ public class CollectionResult<T> implements IQueryResult<T> {
 	private final Collection<T> collection;
 
 	public CollectionResult(Collection<T> collection) {
-		this.collection = collection == null ? CollectionUtils.<T> emptySet() : collection;
+		this.collection = collection == null ? Collections.<T> emptySet() : collection;
 	}
 
 	public IQueryResult<T> query(IQuery<T> query, IProgressMonitor monitor) {
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/Collector.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/Collector.java
index c387ce71a..05b0826cd 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/Collector.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/Collector.java
@@ -15,7 +15,6 @@ import java.lang.reflect.Array;
 import java.util.*;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.internal.p2.metadata.Messages;
 
 /**
@@ -107,7 +106,7 @@ public class Collector<T> implements IQueryResult<T> {
 	 * @return an iterator of the collected objects.
 	 */
 	public Iterator<T> iterator() {
-		return collected == null ? CollectionUtils.<T> emptyList().iterator() : collected.iterator();
+		return collected == null ? Collections.<T> emptyList().iterator() : collected.iterator();
 	}
 
 	/**
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CompoundQueryable.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CompoundQueryable.java
index dab517ce7..6d1f6a58f 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CompoundQueryable.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/CompoundQueryable.java
@@ -11,7 +11,6 @@ package org.eclipse.equinox.p2.query;
 
 import java.util.*;
 import org.eclipse.core.runtime.NullProgressMonitor;
-import org.eclipse.equinox.internal.p2.core.helpers.CollectionUtils;
 import org.eclipse.equinox.internal.p2.metadata.InstallableUnit;
 import org.eclipse.equinox.internal.p2.metadata.expression.CompoundIterator;
 import org.eclipse.equinox.internal.p2.metadata.index.CompoundIndex;
@@ -107,7 +106,7 @@ public final class CompoundQueryable<T> extends IndexProvider<T> {
 
 	public Iterator<T> everything() {
 		if (queryables.length == 0)
-			return CollectionUtils.<T> emptySet().iterator();
+			return Collections.<T> emptySet().iterator();
 
 		if (queryables.length == 1)
 			return getIteratorFromQueryable(queryables[0]);
@@ -150,7 +149,7 @@ public final class CompoundQueryable<T> extends IndexProvider<T> {
 		}
 
 		Iterator<T> getCapturedIterator() {
-			return capturedIterator == null ? CollectionUtils.<T> emptySet().iterator() : capturedIterator;
+			return capturedIterator == null ? Collections.<T> emptySet().iterator() : capturedIterator;
 		}
 	}