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Diffstat (limited to 'javax/management/openmbean/TabularDataSupport.java')
| -rw-r--r-- | javax/management/openmbean/TabularDataSupport.java | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/javax/management/openmbean/TabularDataSupport.java b/javax/management/openmbean/TabularDataSupport.java new file mode 100644 index 000000000..9dc8a0e97 --- /dev/null +++ b/javax/management/openmbean/TabularDataSupport.java @@ -0,0 +1,652 @@ +/* TabularDataSupport.java -- Tables of composite data structures. + Copyright (C) 2006 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package javax.management.openmbean; + +import java.io.Serializable; + +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashMap; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.Set; + +/** + * Provides an implementation of the {@link TabularData} + * interface using a {@link java.util.HashMap}. + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.5 + */ +public class TabularDataSupport + implements TabularData, Serializable, Cloneable, Map +{ + + /** + * Compatible with JDK 1.5 + */ + private static final long serialVersionUID = 5720150593236309827L; + + /** + * Mapping of rows to column values. + * + * @serial the map of rows to column values. + */ + private Map dataMap; + + /** + * The tabular type which represents this tabular data instance. + * + * @serial the type information for this instance. + */ + private TabularType tabularType; + + /** + * Constructs a new empty {@link TabularDataSupport} with the + * specified type. The type may not be null. This constructor + * simply calls the other, with the default initial capacity of + * <code>101</code> and default load factor of <code>0.75</code>. + * + * @param type the tabular type of this tabular data instance. + * @throws IllegalArgumentException if <code>type</code> is + * <code>null</code>. + */ + public TabularDataSupport(TabularType type) + { + this(type, 101, 0.75f); + } + + /** + * Constructs a new empty {@link TabularDataSupport} with the + * specified type and the supplied initial capacity and load factor + * being used for the underlying {@link java.util.HashMap}. The + * type may not be null and the initial capacity and load factor + * must be positive. + * + * @param type the tabular type of this tabular data instance. + * @param cap the initial capacity of the underlying map. + * @param lf the load factor of the underlying map. + * @throws IllegalArgumentException if <code>type</code> is + * <code>null</code>, or + * <code>cap</code> or + * <code>lf</code> are + * negative. + */ + public TabularDataSupport(TabularType type, int cap, float lf) + { + if (type == null) + throw new IllegalArgumentException("The type may not be null."); + tabularType = type; + dataMap = new HashMap(cap, lf); + } + + /** + * Calculates the index the specified {@link CompositeData} value + * would have, if it was to be added to this {@link TabularData} + * instance. This method includes a check that the type of the + * given value is the same as the row type of this instance, but not + * a check for existing instances of the given value. The value + * must also not be <code>null</code>. Possible indices are + * selected by the {@link TabularType#getIndexNames()} method of + * this instance's tabular type. The returned indices are the + * values of the fields in the supplied {@link CompositeData} + * instance that match the names given in the {@link TabularType}. + * + * @param val the {@link CompositeData} value whose index should + * be calculated. + * @return the index the value would take on, if it were to be added. + * @throws NullPointerException if the value is <code>null</code>. + * @throws InvalidOpenTypeException if the value does not match the + * row type of this instance. + */ + public Object[] calculateIndex(CompositeData val) + { + if (!(val.getCompositeType().equals(tabularType.getRowType()))) + throw new InvalidOpenTypeException("The type of the given value " + + "does not match the row type " + + "of this instance."); + List indexNames = tabularType.getIndexNames(); + List matchingIndicies = new ArrayList(indexNames.size()); + Iterator it = indexNames.iterator(); + while (it.hasNext()) + { + String name = (String) it.next(); + matchingIndicies.add(val.get(name)); + } + return matchingIndicies.toArray(); + } + + /** + * Removes all {@link CompositeData} values from the table. + */ + public void clear() + { + dataMap.clear(); + } + + /** + * Returns a shallow clone of the information, as obtained by the + * {@link Object} implementation of {@link Object#clone()}. The map + * is also cloned, but it still references the same objects. + * + * @return a shallow clone of this {@link TabularDataSupport}. + */ + public Object clone() + { + TabularDataSupport clone = null; + try + { + clone = (TabularDataSupport) super.clone(); + clone.setMap((HashMap) ((HashMap) dataMap).clone()); + } + catch (CloneNotSupportedException e) + { + /* This won't happen as we implement Cloneable */ + } + return clone; + } + + /** + * Returns true iff this instance of the {@link TabularData} class + * contains a {@link CompositeData} value at the specified index. + * The method returns <code>false</code> if the given key can + * not be cast to an {@link java.lang.Object} array; otherwise + * it returns the result of {@link #containsKey(java.lang.Object[])}. + * + * + * @param key the key to test for. + * @return true if the key maps to a {@link CompositeData} value. + */ + public boolean containsKey(Object key) + { + if (key instanceof Object[]) + return containsKey((Object[]) key); + else + return false; + } + + /** + * Returns true iff this instance of the {@link TabularData} class + * contains a {@link CompositeData} value at the specified index. + * In any other circumstance, including if the given key + * is <code>null</code> or of the incorrect type, according to + * the {@link TabularType} of this instance, this method returns + * false. + * + * @param key the key to test for. + * @return true if the key maps to a {@link CompositeData} value. + */ + public boolean containsKey(Object[] key) + { + if (key == null) + return false; + if (!(isKeyValid(key))) + return false; + return dataMap.containsKey(key); + } + + /** + * Returns true iff this instance of the {@link TabularData} class + * contains the specified {@link CompositeData} value. If the given + * value is not an instance of {@link CompositeData}, this method + * simply returns false. + * + * @param val the value to test for. + * @return true if the value exists. + */ + public boolean containsValue(Object val) + { + if (val instanceof CompositeData) + return containsValue((CompositeData) val); + else + return false; + } + + /** + * Returns true iff this instance of the {@link TabularData} class + * contains the specified {@link CompositeData} value. + * In any other circumstance, including if the given value + * is <code>null</code> or of the incorrect type, according to + * the {@link TabularType} of this instance, this method returns + * false. + * + * @param val the value to test for. + * @return true if the value exists. + */ + public boolean containsValue(CompositeData val) + { + if (val == null) + return false; + if (!(val.getCompositeType().equals(tabularType.getRowType()))) + return false; + return dataMap.containsValue(val); + } + + /** + * <p> + * Returns a set view of the mappings in this Map. Each element in the + * set is a Map.Entry. The set is backed by the map, so that changes in + * one show up in the other. Modifications made while an iterator is + * in progress cause undefined behavior. If the set supports removal, + * these methods remove the underlying mapping from the map: + * <code>Iterator.remove</code>, <code>Set.remove</code>, + * <code>removeAll</code>, <code>retainAll</code>, and <code>clear</code>. + * Element addition, via <code>add</code> or <code>addAll</code>, is + * not supported via this set. + * </p> + * <p> + * <strong>Note</strong>: using the + * {@link java.util.Map.Entry#setValue(Object) will cause corruption of + * the index to row mappings. + * </p> + * + * @return the set view of all mapping entries + * @see java.util.Map.Entry + */ + public Set entrySet() + { + return dataMap.entrySet(); + } + + /** + * Compares the specified object with this object for equality. + * The object is judged equivalent if it is non-null, and also + * an instance of {@link TabularData} with the same row type, + * and {@link CompositeData} values. The two compared instances may + * be equivalent even if they represent different implementations + * of {@link TabularData}. + * + * @param obj the object to compare for equality. + * @return true if <code>obj</code> is equal to <code>this</code>. + */ + public boolean equals(Object obj) + { + if (!(obj instanceof TabularData)) + return false; + TabularData data = (TabularData) obj; + return tabularType.equals(data.getTabularType()) && + dataMap.values().equals(data.values()); + } + + /** + * Retrieves the value for the specified key by simply + * calling <code>get((Object[]) key)</code>. + * + * @param key the key whose value should be returned. + * @return the matching {@link CompositeData} value, or + * <code>null</code> if one does not exist. + * @throws NullPointerException if the key is <code>null</code>. + * @throws ClassCastException if the key is not an instance + * of <code>Object[]</code>. + * @throws InvalidKeyException if the key does not match + * the {@link TabularType} of this + * instance. + */ + public Object get(Object key) + { + return get((Object[]) key); + } + + /** + * Retrieves the {@link CompositeData} value for the specified + * key, or <code>null</code> if no such mapping exists. + * + * @param key the key whose value should be returned. + * @return the matching {@link CompositeData} value, or + * <code>null</code> if one does not exist. + * @throws NullPointerException if the key is <code>null</code>. + * @throws InvalidKeyException if the key does not match + * the {@link TabularType} of this + * instance. + */ + public CompositeData get(Object[] key) + { + if (!(isKeyValid(key))) + throw new InvalidKeyException("The key does not match the " + + "tabular type of this instance."); + return (CompositeData) dataMap.get(key); + } + + /** + * Returns the tabular type which corresponds to this instance + * of {@link TabularData}. + * + * @return the tabular type for this instance. + */ + public TabularType getTabularType() + { + return tabularType; + } + + /** + * Returns the hash code of the composite data type. This is + * computed as the sum of the hash codes of each value, together + * with the hash code of the tabular type. These are the same + * elements of the type that are compared as part of the {@link + * #equals(java.lang.Object)} method, thus ensuring that the + * hashcode is compatible with the equality test. + * + * @return the hash code of this instance. + */ + public int hashCode() + { + return tabularType.hashCode() + dataMap.values().hashCode(); + } + + /** + * Returns true if this {@link TabularData} instance + * contains no {@link CompositeData} values. + * + * @return true if the instance is devoid of rows. + */ + public boolean isEmpty() + { + return dataMap.isEmpty(); + } + + /** + * Returns true if the given key is valid for the + * @link{TabularType} of this instance. + * + * @return true if the key is valid. + * @throws NullPointerException if <code>key</code> + * is null. + */ + private boolean isKeyValid(Object[] key) + { + Iterator it = tabularType.getIndexNames().iterator(); + CompositeType rowType = tabularType.getRowType(); + for (int a = 0; it.hasNext(); ++a) + { + OpenType type = rowType.getType((String) it.next()); + if (!(type.isValue(key[a]))) + return false; + } + return true; + } + + /** + * Returns a set view of the keys in this Map. The set is backed by the + * map, so that changes in one show up in the other. Modifications made + * while an iterator is in progress cause undefined behavior. If the set + * supports removal, these methods remove the underlying mapping from + * the map: <code>Iterator.remove</code>, <code>Set.remove</code>, + * <code>removeAll</code>, <code>retainAll</code>, and <code>clear</code>. + * Element addition, via <code>add</code> or <code>addAll</code>, is + * not supported via this set. + * + * @return the set view of all keys + */ + public Set keySet() + { + return dataMap.keySet(); + } + + /** + * Adds the specified {@link CompositeData} value to the + * table. The value must be non-null, of the same type + * as the row type of this instance, and must not have + * the same index as an existing value. The index is + * calculated using the index names of the + * {@link TabularType} for this instance. + * + * @param val the {@link CompositeData} value to add. + * @throws NullPointerException if <code>val</code> is + * <code>null</code>. + * @throws InvalidOpenTypeException if the type of the + * given value does not + * match the row type. + * @throws KeyAlreadyExistsException if the value has the + * same calculated index + * as an existing value. + */ + public void put(CompositeData val) + { + Object[] key = calculateIndex(val); + if (dataMap.containsKey(key)) + throw new KeyAlreadyExistsException("A value with this index " + + "already exists."); + dataMap.put(key, val); + } + + /** + * Adds the specified {@link CompositeData} value to the + * table, ignoring the supplied key, by simply calling + * <code>put((CompositeData) val)</code>. + * + * @param key ignored. + * @param val the {@link CompositeData} value to add. + * @return the {@link CompositeData} value. + * @throws NullPointerException if <code>val</code> is + * <code>null</code>. + * @throws InvalidOpenTypeException if the type of the + * given value does not + * match the row type. + * @throws KeyAlreadyExistsException if the value has the + * same calculated index + * as an existing value. + */ + public Object put(Object key, Object val) + { + put((CompositeData) val); + return val; + } + + /** + * Adds each of the specified {@link CompositeData} values + * to the table. Each element of the array must meet the + * conditions given for the {@link #put(CompositeData)} + * method. In addition, the index of each value in the + * array must be distinct from the index of the other + * values in the array, as well as from the existing values + * in the table. The operation should be atomic; if one + * value can not be added, then none of the values should + * be. If the array is <code>null</code> or empty, the + * method simply returns. + * + * @param vals the {@link CompositeData} values to add. + * @throws NullPointerException if a value from the array is + * <code>null</code>. + * @throws InvalidOpenTypeException if the type of a + * given value does not + * match the row type. + * @throws KeyAlreadyExistsException if a value has the + * same calculated index + * as an existing value or + * of one of the other + * specified values. + */ + public void putAll(CompositeData[] vals) + { + if (vals == null || vals.length == 0) + return; + Map mapToAdd = new HashMap(vals.length); + for (int a = 0; a < vals.length; ++a) + { + Object[] key = calculateIndex(vals[a]); + if (dataMap.containsKey(key)) + throw new KeyAlreadyExistsException("Element " + a + ": A " + + "value with this index " + + "already exists."); + mapToAdd.put(key, vals[a]); + } + dataMap.putAll(mapToAdd); + } + + /** + * Converts each value from the specified map to a member of an + * array of {@link CompositeData} values and adds them using {@link + * #put(CompositeData[])}, if possible. As in {@link + * #put(Object,Object)}, the keys are simply ignored. This method + * is useful for adding the {@link CompositeData} values from a + * different {@link TabularData} instance, which uses the same + * {@link TabularType} but a different selection of index names, to + * this one. If the map is <code>null</code> or empty, the method + * simply returns. + * + * @param m the map to add. Only the values are used and must + * all be instances of {@link CompositeData}. + * @throws NullPointerException if a value from the map is + * <code>null</code>. + * @throws ClassCastException if a value from the map is not + * an instance of {@link CompositeData}. + * @throws InvalidOpenTypeException if the type of the + * given value does not + * match the row type. + * @throws KeyAlreadyExistsException if the value has the + * same calculated index + * as an existing value or + * of one of the other + * specified values. + */ + public void putAll(Map m) + { + if (m == null || m.size() == 0) + return; + Collection vals = m.values(); + CompositeData[] data = new CompositeData[vals.size()]; + Iterator it = vals.iterator(); + for (int a = 0; it.hasNext(); ++a) + { + data[a] = (CompositeData) it.next(); + } + putAll(data); + } + + /** + * Removes the value for the specified key by simply + * calling <code>remove((Object[]) key)</code>. + * + * @param key the key whose value should be removed. + * @return the removed value, or <code>null</code> if + * there is no value for the given key. + * @throws NullPointerException if the key is <code>null</code>. + * @throws ClassCastException if the key is not an instance + * of <code>Object[]</code>. + * @throws InvalidOpenTypeException if the key does not match + * the {@link TabularType} of this + * instance. + */ + public Object remove(Object key) + { + return remove((Object[]) key); + } + + /** + * Removes the {@link CompositeData} value located at the + * specified index. <code>null</code> is returned if the + * value does not exist. Otherwise, the removed value is + * returned. + * + * @param key the key of the value to remove. + * @return the removed value, or <code>null</code> if + * there is no value for the given key. + * @throws NullPointerException if the key is <code>null</code>. + * @throws InvalidOpenTypeException if the key does not match + * the {@link TabularType} of this + * instance. + */ + public CompositeData remove(Object[] key) + { + if (!(isKeyValid(key))) + throw new InvalidKeyException("The key does not match the " + + "tabular type of this instance."); + return (CompositeData) dataMap.remove(key); + } + + /** + * Package-private method to set the internal {@link java.util.Map} + * instance (used in cloning). + * + * @param map the new map used. + */ + void setMap(Map map) + { + dataMap = map; + } + + /** + * Returns the number of {@link CompositeData} values or rows + * in the table. + * + * @return the number of rows in the table. + */ + public int size() + { + return dataMap.size(); + } + + /** + * Returns a textual representation of this instance. This + * is constructed using the class name + * (<code>javax.management.openmbean.TabularDataSupport</code>) + * and the result of calling <code>toString()</code> on the + * tabular type and underlying hash map instance. + * + * @return a {@link java.lang.String} representation of the + * object. + */ + public String toString() + { + return getClass().getName() + + "[tabularType=" + tabularType + + ",dataMap=" + dataMap + + "]"; + } + + /** + * Returns a collection (or bag) view of the values in this Map. The + * collection is backed by the map, so that changes in one show up in + * the other. Modifications made while an iterator is in progress cause + * undefined behavior. If the collection supports removal, these methods + * remove the underlying mapping from the map: <code>Iterator.remove</code>, + * <code>Collection.remove</code>, <code>removeAll</code>, + * <code>retainAll</code>, and <code>clear</code>. Element addition, via + * <code>add</code> or <code>addAll</code>, is not supported via this + * collection. + * + * @return the collection view of all values + */ + public Collection values() + { + return dataMap.values(); + } + +} + |