src/main/java/org/apache/sling/api/resource/ResourceMetadata.java - sling-org-apache-sling-api - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */
 package org.apache.sling.api.resource;

 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;

 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.annotations.NotNull;

 /**
  * The <code>ResourceMetadata</code> interface defines the API for the
  * metadata of a Sling {@link Resource}. Essentially the resource's metadata is
  * just a map of objects indexed by string keys.
  * <p>
  * The actual contents of the meta data map is implementation specific with the
  * exception of the {@link #RESOLUTION_PATH sling.resolutionPath} property which
  * must be provided by all implementations and contain the part of the request
  * URI used to resolve the resource. The type of this property value is defined
  * to be <code>String</code>.
  * <p>
  * Note, that the prefix <em>sling.</em> to key names is reserved for the
  * Sling implementation.
  *
  * Once a resource is returned by the {@link ResourceResolver}, the resource
  * metadata is made read-only and therefore can't be changed by client code!
  */
 public class ResourceMetadata extends HashMap<String, Object> {

     private static final long serialVersionUID = 4692666752269523738L;

     /**
      * The name of the required property providing the part of the request URI
      * which was used to the resolve the resource to which the meta data
      * instance belongs (value is "sling.resolutionPath").
      */
     public static final String RESOLUTION_PATH = "sling.resolutionPath";

     /**
      * The name of the required property providing the part of the request URI
      * which was not used to the resolve the resource to which the meta data
      * instance belongs (value is "sling.resolutionPathInfo"). The value of this
      * property concatenated to the value of the
      * {@link #RESOLUTION_PATH sling.resolutionPath} property returns the
      * original request URI leading to the resource.
      * <p>
      * This property is optional. If missing, it should be assumed equal to an
      * empty string.
      *
      * @since 2.0.4 (Sling API Bundle 2.0.4)
      */
     public static final String RESOLUTION_PATH_INFO = "sling.resolutionPathInfo";

     /**
      * The name of the optional property providing the content type of the
      * resource if the resource is streamable (value is "sling.contentType").
      * This property may be missing if the resource is not streamable or if the
      * content type is not known.
      */
     public static final String CONTENT_TYPE = "sling.contentType";

     /**
      * The name of the optional property providing the content length of the
      * resource if the resource is streamable (value is "sling.contentLength").
      * This property may be missing if the resource is not streamable or if the
      * content length is not known.
      * <p>
      * Note, that unlike the other properties, this property may be set only
      * after the resource has successfully been adapted to an
      * <code>InputStream</code> for performance reasons.
      */
     public static final String CONTENT_LENGTH = "sling.contentLength";

     /**
      * The name of the optional property providing the character encoding of the
      * resource if the resource is streamable and contains character data (value
      * is "sling.characterEncoding"). This property may be missing if the
      * resource is not streamable or if the character encoding is not known.
      */
     public static final String CHARACTER_ENCODING = "sling.characterEncoding";

     /**
      * Returns the creation time of this resource in the repository in
      * milliseconds (value is "sling.creationTime"). The type of this property
      * is <code>java.lang.Long</code>. The property may be missing if the
      * resource is not streamable or if the creation time is not known.
      */
     public static final String CREATION_TIME = "sling.creationTime";

     /**
      * Returns the last modification time of this resource in the repository in
      * milliseconds (value is "sling.modificationTime"). The type of this
      * property is <code>java.lang.Long</code>. The property may be missing
      * if the resource is not streamable or if the last modification time is not
      * known.
      */
     public static final String MODIFICATION_TIME = "sling.modificationTime";

     /**
      * Returns whether the resource resolver should continue to search for a
      * resource.
      * A resource provider can set this flag to indicate that the resource
      * resolver should search for a provider with a lower priority. If it
      * finds a resource using such a provider, that resource is returned
      * instead. If none is found this resource is returned.
      * This flag should never be manipulated by application code!
      * The value of this property has no meaning, the resource resolver
      * just checks whether this flag is set or not.
      * @since 2.2 (Sling API Bundle 2.2.0)
      * @deprecated This flag is not supported anymore when implementing the SPI
      *             based {@code org.apache.sling.spi.resource.provider.ResourceProvider}
      */
     public static final String INTERNAL_CONTINUE_RESOLVING = ":org.apache.sling.resource.internal.continue.resolving";

     /**
      * Returns a map containing parameters added to path after semicolon.
      * For instance, map for path <code>/content/test;v='1.2.3'.html</code>
      * will contain one entry key <code>v</code> and value <code>1.2.3</code>.
      */
     public static final String PARAMETER_MAP = "sling.parameterMap";

     private boolean isReadOnly = false;

     /**
      * Sets the {@link #CHARACTER_ENCODING} property to <code>encoding</code>
      * if not <code>null</code>.
      * @param encoding The encoding
      */
     public void setCharacterEncoding(String encoding) {
         if (encoding != null) {
             put(CHARACTER_ENCODING, encoding);
         }
     }

     /**
      * Returns the {@link #CHARACTER_ENCODING} property if not <code>null</code>
      * and a <code>String</code> instance. Otherwise <code>null</code> is
      * returned.
      * @return The character encoding
      */
     public @Nullable String getCharacterEncoding() {
         Object value = get(CHARACTER_ENCODING);
         if (value instanceof String) {
             return (String) value;
         }

         return null;
     }

     /**
      * Sets the {@link #CONTENT_TYPE} property to <code>contentType</code> if
      * not <code>null</code>.
      * @param contentType The content type
      */
     public void setContentType(String contentType) {
         if (contentType != null) {
             put(CONTENT_TYPE, contentType);
         }
     }

     /**
      * Returns the {@link #CONTENT_TYPE} property if not <code>null</code> and
      * a <code>String</code> instance. Otherwise <code>null</code> is
      * returned.
      * @return The content type
      */
     public @Nullable String getContentType() {
         Object value = get(CONTENT_TYPE);
         if (value instanceof String) {
             return (String) value;
         }

         return null;
     }

     /**
      * Sets the {@link #CONTENT_LENGTH} property to <code>contentType</code>
      * if not <code>null</code>.
      * @param contentLength The content length
      */
     public void setContentLength(long contentLength) {
         if (contentLength > 0) {
             put(CONTENT_LENGTH, contentLength);
         }
     }

     /**
      * Returns the {@link #CONTENT_LENGTH} property if not <code>null</code>
      * and a <code>long</code>. Otherwise <code>-1</code> is returned.
      * @return The content length
      */
     public long getContentLength() {
         Object value = get(CONTENT_LENGTH);
         if (value instanceof Long) {
             return (Long) value;
         }

         return -1;
     }

     /**
      * Sets the {@link #CREATION_TIME} property to <code>creationTime</code>
      * if not negative.
      * @param creationTime The creation time
      */
     public void setCreationTime(long creationTime) {
         if (creationTime >= 0) {
             put(CREATION_TIME, creationTime);
         }
     }

     /**
      * Returns the {@link #CREATION_TIME} property if not <code>null</code>
      * and a <code>long</code>. Otherwise <code>-1</code> is returned.
      * @return The creation time
      */
     public long getCreationTime() {
         Object value = get(CREATION_TIME);
         if (value instanceof Long) {
             return (Long) value;
         }

         return -1;
     }

     /**
      * Sets the {@link #MODIFICATION_TIME} property to
      * <code>modificationTime</code> if not negative.
      * @param modificationTime The modification time
      */
     public void setModificationTime(long modificationTime) {
         if (modificationTime >= 0) {
             put(MODIFICATION_TIME, modificationTime);
         }
     }

     /**
      * Returns the {@link #MODIFICATION_TIME} property if not <code>null</code>
      * and a <code>long</code>. Otherwise <code>-1</code> is returned.
      * @return The modification time
      */
     public long getModificationTime() {
         Object value = get(MODIFICATION_TIME);
         if (value instanceof Long) {
             return (Long) value;
         }

         return -1;
     }

     /**
      * Sets the {@link #RESOLUTION_PATH} property to <code>resolutionPath</code>
      * if not <code>null</code>.
      * @param resolutionPath The resolution path
      */
     public void setResolutionPath(String resolutionPath) {
         if (resolutionPath != null) {
             put(RESOLUTION_PATH, resolutionPath);
         }
     }

     /**
      * Returns the {@link #RESOLUTION_PATH} property if not <code>null</code>
      * and a <code>String</code> instance. Otherwise <code>null</code> is
      * returned.
      * @return The resolution path
      */
     public @Nullable String getResolutionPath() {
         Object value = get(RESOLUTION_PATH);
         if (value instanceof String) {
             return (String) value;
         }

         return null;
     }

     /**
      * Sets the {@link #RESOLUTION_PATH_INFO} property to
      * <code>resolutionPathInfo</code> if not <code>null</code>.
      * @param resolutionPathInfo The resolution path info
      */
     public void setResolutionPathInfo(String resolutionPathInfo) {
         if (resolutionPathInfo != null) {
             put(RESOLUTION_PATH_INFO, resolutionPathInfo);
         }
     }

     /**
      * Returns the {@link #RESOLUTION_PATH_INFO} property if not
      * <code>null</code> and a <code>String</code> instance. Otherwise
      * <code>null</code> is returned.
      * @return The resolution path info
      */
     public @Nullable String getResolutionPathInfo() {
         Object value = get(RESOLUTION_PATH_INFO);
         if (value instanceof String) {
             return (String) value;
         }

         return null;
     }

     /**
      * Sets the {@link #PARAMETER_MAP} property to
      * <code>parameterMap</code> if not <code>null</code>.
      * @param parameterMap The parameter map
      */
     public void setParameterMap(Map<String, String> parameterMap) {
         if (parameterMap != null) {
             if (parameterMap.isEmpty()) {
                 put(PARAMETER_MAP, Collections.emptyMap());
             } else {
                 put(PARAMETER_MAP, new LinkedHashMap<String, String>(parameterMap));
             }
         }
     }

     /**
      * Returns the {@link #PARAMETER_MAP} property if not
      * <code>null</code> and a <code>Map</code> instance. Otherwise
      * <code>null</code> is returned.
      * @return The parameter map
      */
     @SuppressWarnings("unchecked")
     public @Nullable Map<String, String> getParameterMap() {
         Object value = get(PARAMETER_MAP);
         if (value instanceof Map) {
             return (Map<String, String>) value;
         }

         return null;
     }


     /**
      * Make this object read-only. All method calls trying to modify this object
      * result in an exception!
      * @since 2.3 (Sling API Bundle 2.4.0)
      */
     public void lock() {
         this.isReadOnly = true;
     }

     /**
      * Check if this object is read only and if so throw an unsupported operation exception.
      */
     private void checkReadOnly() {
         if ( this.isReadOnly ) {
             throw new UnsupportedOperationException(getClass().getSimpleName() + " is locked");
         }
     }

     @Override
     public void clear() {
         this.checkReadOnly();
         super.clear();
     }

     @Override
     public Object put(@NotNull final String key, final Object value) {
         this.checkReadOnly();
         return super.put(key, value);
     }

     @Override
     public void putAll(@NotNull final Map<? extends String, ? extends Object> m) {
         this.checkReadOnly();
         super.putAll(m);
     }

     @Override
     public Object remove(@NotNull final Object key) {
         this.checkReadOnly();
         return super.remove(key);
     }

     protected void internalPut(@NotNull String key, Object value) {
         super.put(key, value);
     }

     @Override
     public Object clone() {
         ResourceMetadata result = (ResourceMetadata) super.clone();
         result.lockedEntrySet = null;
         result.lockedKeySet = null;
         result.lockedValues = null;
         return result;
     }

 	// volatile for correct double-checked locking in getLockedData()
     private transient volatile Set<Map.Entry<String, Object>> lockedEntrySet;
     private transient Set<String> lockedKeySet;
     private transient Collection<Object> lockedValues;

     private void getLockedData() {
         if(isReadOnly && lockedEntrySet == null) {
             synchronized (this) {
                 if(isReadOnly && lockedEntrySet == null) {
                     lockedEntrySet = Collections.unmodifiableSet(super.entrySet());
                     lockedKeySet = Collections.unmodifiableSet(super.keySet());
                     lockedValues = Collections.unmodifiableCollection(super.values());
                 }
             }
         }
     }

     @Override
     public @NotNull Set<Map.Entry<String, Object>> entrySet() {
         getLockedData();
         return lockedEntrySet != null ? lockedEntrySet : super.entrySet();
     }

     @Override
     public @NotNull Set<String> keySet() {
         getLockedData();
         return lockedKeySet != null ? lockedKeySet : super.keySet();
     }

     @Override
     public @NotNull Collection<Object> values() {
         getLockedData();
         return lockedValues != null ? lockedValues : super.values();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package org.apache.sling.api.resource;

	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.LinkedHashMap;
	import java.util.Map;
	import java.util.Set;

	import org.jetbrains.annotations.Nullable;
	import org.jetbrains.annotations.NotNull;

	/**
	* The <code>ResourceMetadata</code> interface defines the API for the
	* metadata of a Sling {@link Resource}. Essentially the resource's metadata is
	* just a map of objects indexed by string keys.
	* <p>
	* The actual contents of the meta data map is implementation specific with the
	* exception of the {@link #RESOLUTION_PATH sling.resolutionPath} property which
	* must be provided by all implementations and contain the part of the request
	* URI used to resolve the resource. The type of this property value is defined
	* to be <code>String</code>.
	* <p>
	* Note, that the prefix <em>sling.</em> to key names is reserved for the
	* Sling implementation.
	*
	* Once a resource is returned by the {@link ResourceResolver}, the resource
	* metadata is made read-only and therefore can't be changed by client code!
	*/
	public class ResourceMetadata extends HashMap<String, Object> {

	private static final long serialVersionUID = 4692666752269523738L;

	/**
	* The name of the required property providing the part of the request URI
	* which was used to the resolve the resource to which the meta data
	* instance belongs (value is "sling.resolutionPath").
	*/
	public static final String RESOLUTION_PATH = "sling.resolutionPath";

	/**
	* The name of the required property providing the part of the request URI
	* which was not used to the resolve the resource to which the meta data
	* instance belongs (value is "sling.resolutionPathInfo"). The value of this
	* property concatenated to the value of the
	* {@link #RESOLUTION_PATH sling.resolutionPath} property returns the
	* original request URI leading to the resource.
	* <p>
	* This property is optional. If missing, it should be assumed equal to an
	* empty string.
	*
	* @since 2.0.4 (Sling API Bundle 2.0.4)
	*/
	public static final String RESOLUTION_PATH_INFO = "sling.resolutionPathInfo";

	/**
	* The name of the optional property providing the content type of the
	* resource if the resource is streamable (value is "sling.contentType").
	* This property may be missing if the resource is not streamable or if the
	* content type is not known.
	*/
	public static final String CONTENT_TYPE = "sling.contentType";

	/**
	* The name of the optional property providing the content length of the
	* resource if the resource is streamable (value is "sling.contentLength").
	* This property may be missing if the resource is not streamable or if the
	* content length is not known.
	* <p>
	* Note, that unlike the other properties, this property may be set only
	* after the resource has successfully been adapted to an
	* <code>InputStream</code> for performance reasons.
	*/
	public static final String CONTENT_LENGTH = "sling.contentLength";

	/**
	* The name of the optional property providing the character encoding of the
	* resource if the resource is streamable and contains character data (value
	* is "sling.characterEncoding"). This property may be missing if the
	* resource is not streamable or if the character encoding is not known.
	*/
	public static final String CHARACTER_ENCODING = "sling.characterEncoding";

	/**
	* Returns the creation time of this resource in the repository in
	* milliseconds (value is "sling.creationTime"). The type of this property
	* is <code>java.lang.Long</code>. The property may be missing if the
	* resource is not streamable or if the creation time is not known.
	*/
	public static final String CREATION_TIME = "sling.creationTime";

	/**
	* Returns the last modification time of this resource in the repository in
	* milliseconds (value is "sling.modificationTime"). The type of this
	* property is <code>java.lang.Long</code>. The property may be missing
	* if the resource is not streamable or if the last modification time is not
	* known.
	*/
	public static final String MODIFICATION_TIME = "sling.modificationTime";

	/**
	* Returns whether the resource resolver should continue to search for a
	* resource.
	* A resource provider can set this flag to indicate that the resource
	* resolver should search for a provider with a lower priority. If it
	* finds a resource using such a provider, that resource is returned
	* instead. If none is found this resource is returned.
	* This flag should never be manipulated by application code!
	* The value of this property has no meaning, the resource resolver
	* just checks whether this flag is set or not.
	* @since 2.2 (Sling API Bundle 2.2.0)
	* @deprecated This flag is not supported anymore when implementing the SPI
	* based {@code org.apache.sling.spi.resource.provider.ResourceProvider}
	*/
	public static final String INTERNAL_CONTINUE_RESOLVING = ":org.apache.sling.resource.internal.continue.resolving";

	/**
	* Returns a map containing parameters added to path after semicolon.
	* For instance, map for path <code>/content/test;v='1.2.3'.html</code>
	* will contain one entry key <code>v</code> and value <code>1.2.3</code>.
	*/
	public static final String PARAMETER_MAP = "sling.parameterMap";

	private boolean isReadOnly = false;

	/**
	* Sets the {@link #CHARACTER_ENCODING} property to <code>encoding</code>
	* if not <code>null</code>.
	* @param encoding The encoding
	*/
	public void setCharacterEncoding(String encoding) {
	if (encoding != null) {
	put(CHARACTER_ENCODING, encoding);
	}
	}

	/**
	* Returns the {@link #CHARACTER_ENCODING} property if not <code>null</code>
	* and a <code>String</code> instance. Otherwise <code>null</code> is
	* returned.
	* @return The character encoding
	*/
	public @Nullable String getCharacterEncoding() {
	Object value = get(CHARACTER_ENCODING);
	if (value instanceof String) {
	return (String) value;
	}

	return null;
	}

	/**
	* Sets the {@link #CONTENT_TYPE} property to <code>contentType</code> if
	* not <code>null</code>.
	* @param contentType The content type
	*/
	public void setContentType(String contentType) {
	if (contentType != null) {
	put(CONTENT_TYPE, contentType);
	}
	}

	/**
	* Returns the {@link #CONTENT_TYPE} property if not <code>null</code> and
	* a <code>String</code> instance. Otherwise <code>null</code> is
	* returned.
	* @return The content type
	*/
	public @Nullable String getContentType() {
	Object value = get(CONTENT_TYPE);
	if (value instanceof String) {
	return (String) value;
	}

	return null;
	}

	/**
	* Sets the {@link #CONTENT_LENGTH} property to <code>contentType</code>
	* if not <code>null</code>.
	* @param contentLength The content length
	*/
	public void setContentLength(long contentLength) {
	if (contentLength > 0) {
	put(CONTENT_LENGTH, contentLength);
	}
	}

	/**
	* Returns the {@link #CONTENT_LENGTH} property if not <code>null</code>
	* and a <code>long</code>. Otherwise <code>-1</code> is returned.
	* @return The content length
	*/
	public long getContentLength() {
	Object value = get(CONTENT_LENGTH);
	if (value instanceof Long) {
	return (Long) value;
	}

	return -1;
	}

	/**
	* Sets the {@link #CREATION_TIME} property to <code>creationTime</code>
	* if not negative.
	* @param creationTime The creation time
	*/
	public void setCreationTime(long creationTime) {
	if (creationTime >= 0) {
	put(CREATION_TIME, creationTime);
	}
	}

	/**
	* Returns the {@link #CREATION_TIME} property if not <code>null</code>
	* and a <code>long</code>. Otherwise <code>-1</code> is returned.
	* @return The creation time
	*/
	public long getCreationTime() {
	Object value = get(CREATION_TIME);
	if (value instanceof Long) {
	return (Long) value;
	}

	return -1;
	}

	/**
	* Sets the {@link #MODIFICATION_TIME} property to
	* <code>modificationTime</code> if not negative.
	* @param modificationTime The modification time
	*/
	public void setModificationTime(long modificationTime) {
	if (modificationTime >= 0) {
	put(MODIFICATION_TIME, modificationTime);
	}
	}

	/**
	* Returns the {@link #MODIFICATION_TIME} property if not <code>null</code>
	* and a <code>long</code>. Otherwise <code>-1</code> is returned.
	* @return The modification time
	*/
	public long getModificationTime() {
	Object value = get(MODIFICATION_TIME);
	if (value instanceof Long) {
	return (Long) value;
	}

	return -1;
	}

	/**
	* Sets the {@link #RESOLUTION_PATH} property to <code>resolutionPath</code>
	* if not <code>null</code>.
	* @param resolutionPath The resolution path
	*/
	public void setResolutionPath(String resolutionPath) {
	if (resolutionPath != null) {
	put(RESOLUTION_PATH, resolutionPath);
	}
	}

	/**
	* Returns the {@link #RESOLUTION_PATH} property if not <code>null</code>
	* and a <code>String</code> instance. Otherwise <code>null</code> is
	* returned.
	* @return The resolution path
	*/
	public @Nullable String getResolutionPath() {
	Object value = get(RESOLUTION_PATH);
	if (value instanceof String) {
	return (String) value;
	}

	return null;
	}

	/**
	* Sets the {@link #RESOLUTION_PATH_INFO} property to
	* <code>resolutionPathInfo</code> if not <code>null</code>.
	* @param resolutionPathInfo The resolution path info
	*/
	public void setResolutionPathInfo(String resolutionPathInfo) {
	if (resolutionPathInfo != null) {
	put(RESOLUTION_PATH_INFO, resolutionPathInfo);
	}
	}

	/**
	* Returns the {@link #RESOLUTION_PATH_INFO} property if not
	* <code>null</code> and a <code>String</code> instance. Otherwise
	* <code>null</code> is returned.
	* @return The resolution path info
	*/
	public @Nullable String getResolutionPathInfo() {
	Object value = get(RESOLUTION_PATH_INFO);
	if (value instanceof String) {
	return (String) value;
	}

	return null;
	}

	/**
	* Sets the {@link #PARAMETER_MAP} property to
	* <code>parameterMap</code> if not <code>null</code>.
	* @param parameterMap The parameter map
	*/
	public void setParameterMap(Map<String, String> parameterMap) {
	if (parameterMap != null) {
	if (parameterMap.isEmpty()) {
	put(PARAMETER_MAP, Collections.emptyMap());
	} else {
	put(PARAMETER_MAP, new LinkedHashMap<String, String>(parameterMap));
	}
	}
	}

	/**
	* Returns the {@link #PARAMETER_MAP} property if not
	* <code>null</code> and a <code>Map</code> instance. Otherwise
	* <code>null</code> is returned.
	* @return The parameter map
	*/
	@SuppressWarnings("unchecked")
	public @Nullable Map<String, String> getParameterMap() {
	Object value = get(PARAMETER_MAP);
	if (value instanceof Map) {
	return (Map<String, String>) value;
	}

	return null;
	}


	/**
	* Make this object read-only. All method calls trying to modify this object
	* result in an exception!
	* @since 2.3 (Sling API Bundle 2.4.0)
	*/
	public void lock() {
	this.isReadOnly = true;
	}

	/**
	* Check if this object is read only and if so throw an unsupported operation exception.
	*/
	private void checkReadOnly() {
	if ( this.isReadOnly ) {
	throw new UnsupportedOperationException(getClass().getSimpleName() + " is locked");
	}
	}

	@Override
	public void clear() {
	this.checkReadOnly();
	super.clear();
	}

	@Override
	public Object put(@NotNull final String key, final Object value) {
	this.checkReadOnly();
	return super.put(key, value);
	}

	@Override
	public void putAll(@NotNull final Map<? extends String, ? extends Object> m) {
	this.checkReadOnly();
	super.putAll(m);
	}

	@Override
	public Object remove(@NotNull final Object key) {
	this.checkReadOnly();
	return super.remove(key);
	}

	protected void internalPut(@NotNull String key, Object value) {
	super.put(key, value);
	}

	@Override
	public Object clone() {
	ResourceMetadata result = (ResourceMetadata) super.clone();
	result.lockedEntrySet = null;
	result.lockedKeySet = null;
	result.lockedValues = null;
	return result;
	}

	// volatile for correct double-checked locking in getLockedData()
	private transient volatile Set<Map.Entry<String, Object>> lockedEntrySet;
	private transient Set<String> lockedKeySet;
	private transient Collection<Object> lockedValues;

	private void getLockedData() {
	if(isReadOnly && lockedEntrySet == null) {
	synchronized (this) {
	if(isReadOnly && lockedEntrySet == null) {
	lockedEntrySet = Collections.unmodifiableSet(super.entrySet());
	lockedKeySet = Collections.unmodifiableSet(super.keySet());
	lockedValues = Collections.unmodifiableCollection(super.values());
	}
	}
	}
	}

	@Override
	public @NotNull Set<Map.Entry<String, Object>> entrySet() {
	getLockedData();
	return lockedEntrySet != null ? lockedEntrySet : super.entrySet();
	}

	@Override
	public @NotNull Set<String> keySet() {
	getLockedData();
	return lockedKeySet != null ? lockedKeySet : super.keySet();
	}

	@Override
	public @NotNull Collection<Object> values() {
	getLockedData();
	return lockedValues != null ? lockedValues : super.values();
	}
	}