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Diffstat (limited to 'velocity-engine-core/src/main/java/org/apache/velocity/VelocityContext.java')
-rw-r--r-- | velocity-engine-core/src/main/java/org/apache/velocity/VelocityContext.java | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/VelocityContext.java b/velocity-engine-core/src/main/java/org/apache/velocity/VelocityContext.java new file mode 100644 index 00000000..9b4a6e4a --- /dev/null +++ b/velocity-engine-core/src/main/java/org/apache/velocity/VelocityContext.java @@ -0,0 +1,196 @@ +package org.apache.velocity; + +/* + * 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. + */ + +import org.apache.velocity.context.AbstractContext; +import org.apache.velocity.context.Context; + +import java.io.Serializable; +import java.util.HashMap; +import java.util.Map; + +/** + * General purpose implementation of the application Context + * interface for general application use. This class should + * be used in place of the original Context class. + * + * This implementation uses a HashMap (@see java.util.HashMap ) + * for data storage. + * + * This context implementation cannot be shared between threads + * without those threads synchronizing access between them, as + * the HashMap is not synchronized, nor are some of the fundamentals + * of AbstractContext. If you need to share a Context between + * threads with simultaneous access for some reason, please create + * your own and extend the interface Context + * + * @see org.apache.velocity.context.Context + * + * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> + * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> + * @author <a href="mailto:fedor.karpelevitch@home.com">Fedor Karpelevitch</a> + * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> + * @version $Id$ + */ +public class VelocityContext + extends AbstractContext + implements Cloneable, Serializable +{ + /** + * Version Id for serializable + */ + private static final long serialVersionUID = 9033846851064645037L; + + /** + * Storage for key/value pairs. + */ + private Map<String, Object> context = null; + + /** + * Creates a new instance (with no inner context). + */ + public VelocityContext() + { + this(null, null); + } + + /** + * Creates a new instance with the provided storage (and no inner + * context). + * @param context + */ + public VelocityContext(Map<String, Object> context) + { + this(context, null); + } + + /** + * Chaining constructor, used when you want to + * wrap a context in another. The inner context + * will be 'read only' - put() calls to the + * wrapping context will only effect the outermost + * context + * + * @param innerContext The <code>Context</code> implementation to + * wrap. + */ + public VelocityContext( Context innerContext ) + { + this(null, innerContext); + } + + /** + * Initializes internal storage (never to <code>null</code>), and + * inner context. + * + * @param context Internal storage, or <code>null</code> to + * create default storage. + * @param innerContext Inner context. + */ + public VelocityContext(Map<String, Object> context, Context innerContext) + { + super(innerContext); + this.context = (context == null ? new HashMap<>() : context); + } + + /** + * retrieves value for key from internal + * storage + * + * @param key name of value to get + * @return value as object + */ + @Override + public Object internalGet(String key ) + { + return context.get( key ); + } + + /** + * stores the value for key to internal + * storage + * + * @param key name of value to store + * @param value value to store + * @return previous value of key as Object + */ + @Override + public Object internalPut(String key, Object value ) + { + return context.put( key, value ); + } + + /** + * determines if there is a value for the + * given key + * + * @param key name of value to check + * @return true if non-null value in store + */ + @Override + public boolean internalContainsKey(String key) + { + return context.containsKey( key ); + } + + /** + * returns array of keys + * + * @return keys as [] + */ + @Override + public String[] internalGetKeys() + { + return context.keySet().toArray(new String[context.size()]); + } + + /** + * remove a key/value pair from the + * internal storage + * + * @param key name of value to remove + * @return value removed + */ + @Override + public Object internalRemove(String key) + { + return context.remove( key ); + } + + /** + * Clones this context object. + * + * @return A shallow copy of this <code>Context</code>. + */ + @Override + public Object clone() + { + VelocityContext clone = null; + try + { + clone = (VelocityContext) super.clone(); + clone.context = new HashMap<>(context); + } + catch (CloneNotSupportedException ignored) + { + } + return clone; + } +} |