--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/management/ImmutableDescriptor.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,567 @@
+/*
+ * Copyright 2004-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.management;
+
+import java.io.InvalidObjectException;
+import java.lang.reflect.Array;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+/**
+ * An immutable descriptor.
+ * @since 1.6
+ */
+public class ImmutableDescriptor implements Descriptor {
+ private static final long serialVersionUID = 8853308591080540165L;
+
+ /**
+ * The names of the fields in this ImmutableDescriptor with their
+ * original case. The names must be in alphabetical order as determined
+ * by {@link String#CASE_INSENSITIVE_ORDER}.
+ */
+ private final String[] names;
+ /**
+ * The values of the fields in this ImmutableDescriptor. The
+ * elements in this array match the corresponding elements in the
+ * {@code names} array.
+ */
+ private final Object[] values;
+
+ private transient int hashCode = -1;
+
+ /**
+ * An empty descriptor.
+ */
+ public static final ImmutableDescriptor EMPTY_DESCRIPTOR =
+ new ImmutableDescriptor();
+
+ /**
+ * Construct a descriptor containing the given fields and values.
+ *
+ * @throws IllegalArgumentException if either array is null, or
+ * if the arrays have different sizes, or
+ * if a field name is null or empty, or if the same field name
+ * appears more than once.
+ */
+ public ImmutableDescriptor(String[] fieldNames, Object[] fieldValues) {
+ this(makeMap(fieldNames, fieldValues));
+ }
+
+ /**
+ * Construct a descriptor containing the given fields. Each String
+ * must be of the form {@code fieldName=fieldValue}. The field name
+ * ends at the first {@code =} character; for example if the String
+ * is {@code a=b=c} then the field name is {@code a} and its value
+ * is {@code b=c}.
+ *
+ * @throws IllegalArgumentException if the parameter is null, or
+ * if a field name is empty, or if the same field name appears
+ * more than once, or if one of the strings does not contain
+ * an {@code =} character.
+ */
+ public ImmutableDescriptor(String... fields) {
+ this(makeMap(fields));
+ }
+
+ /**
+ * <p>Construct a descriptor where the names and values of the fields
+ * are the keys and values of the given Map.</p>
+ *
+ * @throws IllegalArgumentException if the parameter is null, or
+ * if a field name is null or empty, or if the same field name appears
+ * more than once (which can happen because field names are not case
+ * sensitive).
+ */
+ public ImmutableDescriptor(Map<String, ?> fields) {
+ if (fields == null)
+ throw new IllegalArgumentException("Null Map");
+ SortedMap<String, Object> map =
+ new TreeMap<String, Object>(String.CASE_INSENSITIVE_ORDER);
+ for (Map.Entry<String, ?> entry : fields.entrySet()) {
+ String name = entry.getKey();
+ if (name == null || name.equals(""))
+ throw new IllegalArgumentException("Empty or null field name");
+ if (map.containsKey(name))
+ throw new IllegalArgumentException("Duplicate name: " + name);
+ map.put(name, entry.getValue());
+ }
+ int size = map.size();
+ this.names = map.keySet().toArray(new String[size]);
+ this.values = map.values().toArray(new Object[size]);
+ }
+
+ /**
+ * This method can replace a deserialized instance of this
+ * class with another instance. For example, it might replace
+ * a deserialized empty ImmutableDescriptor with
+ * {@link #EMPTY_DESCRIPTOR}.
+ *
+ * @return the replacement object, which may be {@code this}.
+ *
+ * @throws InvalidObjectException if the read object has invalid fields.
+ */
+ private Object readResolve() throws InvalidObjectException {
+ if (names.length == 0 && getClass() == ImmutableDescriptor.class)
+ return EMPTY_DESCRIPTOR;
+
+ boolean bad = false;
+ if (names == null || values == null || names.length != values.length)
+ bad = true;
+ if (!bad) {
+ final Comparator<String> compare = String.CASE_INSENSITIVE_ORDER;
+ String lastName = ""; // also catches illegal null name
+ for (int i = 0; i < names.length; i++) {
+ if (names[i] == null ||
+ compare.compare(lastName, names[i]) >= 0) {
+ bad = true;
+ break;
+ }
+ lastName = names[i];
+ }
+ }
+ if (bad)
+ throw new InvalidObjectException("Bad names or values");
+
+ return this;
+ }
+
+ private static SortedMap<String, ?> makeMap(String[] fieldNames,
+ Object[] fieldValues) {
+ if (fieldNames == null || fieldValues == null)
+ throw new IllegalArgumentException("Null array parameter");
+ if (fieldNames.length != fieldValues.length)
+ throw new IllegalArgumentException("Different size arrays");
+ SortedMap<String, Object> map =
+ new TreeMap<String, Object>(String.CASE_INSENSITIVE_ORDER);
+ for (int i = 0; i < fieldNames.length; i++) {
+ String name = fieldNames[i];
+ if (name == null || name.equals(""))
+ throw new IllegalArgumentException("Empty or null field name");
+ Object old = map.put(name, fieldValues[i]);
+ if (old != null) {
+ throw new IllegalArgumentException("Duplicate field name: " +
+ name);
+ }
+ }
+ return map;
+ }
+
+ private static SortedMap<String, ?> makeMap(String[] fields) {
+ if (fields == null)
+ throw new IllegalArgumentException("Null fields parameter");
+ String[] fieldNames = new String[fields.length];
+ String[] fieldValues = new String[fields.length];
+ for (int i = 0; i < fields.length; i++) {
+ String field = fields[i];
+ int eq = field.indexOf('=');
+ if (eq < 0) {
+ throw new IllegalArgumentException("Missing = character: " +
+ field);
+ }
+ fieldNames[i] = field.substring(0, eq);
+ // makeMap will catch the case where the name is empty
+ fieldValues[i] = field.substring(eq + 1);
+ }
+ return makeMap(fieldNames, fieldValues);
+ }
+
+ /**
+ * <p>Return an {@code ImmutableDescriptor} whose contents are the union of
+ * the given descriptors. Every field name that appears in any of
+ * the descriptors will appear in the result with the
+ * value that it has when the method is called. Subsequent changes
+ * to any of the descriptors do not affect the ImmutableDescriptor
+ * returned here.</p>
+ *
+ * <p>In the simplest case, there is only one descriptor and the
+ * returned {@code ImmutableDescriptor} is a copy of its fields at the
+ * time this method is called:</p>
+ *
+ * <pre>
+ * Descriptor d = something();
+ * ImmutableDescriptor copy = ImmutableDescriptor.union(d);
+ * </pre>
+ *
+ * @param descriptors the descriptors to be combined. Any of the
+ * descriptors can be null, in which case it is skipped.
+ *
+ * @return an {@code ImmutableDescriptor} that is the union of the given
+ * descriptors. The returned object may be identical to one of the
+ * input descriptors if it is an ImmutableDescriptor that contains all of
+ * the required fields.
+ *
+ * @throws IllegalArgumentException if two Descriptors contain the
+ * same field name with different associated values. Primitive array
+ * values are considered the same if they are of the same type with
+ * the same elements. Object array values are considered the same if
+ * {@link Arrays#deepEquals(Object[],Object[])} returns true.
+ */
+ public static ImmutableDescriptor union(Descriptor... descriptors) {
+ // Optimize the case where exactly one Descriptor is non-Empty
+ // and it is immutable - we can just return it.
+ int index = findNonEmpty(descriptors, 0);
+ if (index < 0)
+ return EMPTY_DESCRIPTOR;
+ if (descriptors[index] instanceof ImmutableDescriptor
+ && findNonEmpty(descriptors, index + 1) < 0)
+ return (ImmutableDescriptor) descriptors[index];
+
+ Map<String, Object> map =
+ new TreeMap<String, Object>(String.CASE_INSENSITIVE_ORDER);
+ ImmutableDescriptor biggestImmutable = EMPTY_DESCRIPTOR;
+ for (Descriptor d : descriptors) {
+ if (d != null) {
+ String[] names;
+ if (d instanceof ImmutableDescriptor) {
+ ImmutableDescriptor id = (ImmutableDescriptor) d;
+ names = id.names;
+ if (id.getClass() == ImmutableDescriptor.class
+ && names.length > biggestImmutable.names.length)
+ biggestImmutable = id;
+ } else
+ names = d.getFieldNames();
+ for (String n : names) {
+ Object v = d.getFieldValue(n);
+ Object old = map.put(n, v);
+ if (old != null) {
+ boolean equal;
+ if (old.getClass().isArray()) {
+ equal = Arrays.deepEquals(new Object[] {old},
+ new Object[] {v});
+ } else
+ equal = old.equals(v);
+ if (!equal) {
+ final String msg =
+ "Inconsistent values for descriptor field " +
+ n + ": " + old + " :: " + v;
+ throw new IllegalArgumentException(msg);
+ }
+ }
+ }
+ }
+ }
+ if (biggestImmutable.names.length == map.size())
+ return biggestImmutable;
+ return new ImmutableDescriptor(map);
+ }
+
+ private static boolean isEmpty(Descriptor d) {
+ if (d == null)
+ return true;
+ else if (d instanceof ImmutableDescriptor)
+ return ((ImmutableDescriptor) d).names.length == 0;
+ else
+ return (d.getFieldNames().length == 0);
+ }
+
+ private static int findNonEmpty(Descriptor[] ds, int start) {
+ for (int i = start; i < ds.length; i++) {
+ if (!isEmpty(ds[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ private int fieldIndex(String name) {
+ return Arrays.binarySearch(names, name, String.CASE_INSENSITIVE_ORDER);
+ }
+
+ public final Object getFieldValue(String fieldName) {
+ checkIllegalFieldName(fieldName);
+ int i = fieldIndex(fieldName);
+ if (i < 0)
+ return null;
+ Object v = values[i];
+ if (v == null || !v.getClass().isArray())
+ return v;
+ if (v instanceof Object[])
+ return ((Object[]) v).clone();
+ // clone the primitive array, could use an 8-way if/else here
+ int len = Array.getLength(v);
+ Object a = Array.newInstance(v.getClass().getComponentType(), len);
+ System.arraycopy(v, 0, a, 0, len);
+ return a;
+ }
+
+ public final String[] getFields() {
+ String[] result = new String[names.length];
+ for (int i = 0; i < result.length; i++) {
+ Object value = values[i];
+ if (value == null)
+ value = "";
+ else if (!(value instanceof String))
+ value = "(" + value + ")";
+ result[i] = names[i] + "=" + value;
+ }
+ return result;
+ }
+
+ public final Object[] getFieldValues(String... fieldNames) {
+ if (fieldNames == null)
+ return values.clone();
+ Object[] result = new Object[fieldNames.length];
+ for (int i = 0; i < fieldNames.length; i++) {
+ String name = fieldNames[i];
+ if (name != null && !name.equals(""))
+ result[i] = getFieldValue(name);
+ }
+ return result;
+ }
+
+ public final String[] getFieldNames() {
+ return names.clone();
+ }
+
+ /**
+ * Compares this descriptor to the given object. The objects are equal if
+ * the given object is also a Descriptor, and if the two Descriptors have
+ * the same field names (possibly differing in case) and the same
+ * associated values. The respective values for a field in the two
+ * Descriptors are equal if the following conditions hold:</p>
+ *
+ * <ul>
+ * <li>If one value is null then the other must be too.</li>
+ * <li>If one value is a primitive array then the other must be a primitive
+ * array of the same type with the same elements.</li>
+ * <li>If one value is an object array then the other must be too and
+ * {@link Arrays#deepEquals(Object[],Object[])} must return true.</li>
+ * <li>Otherwise {@link Object#equals(Object)} must return true.</li>
+ * </ul>
+ *
+ * @param o the object to compare with.
+ *
+ * @return {@code true} if the objects are the same; {@code false}
+ * otherwise.
+ *
+ */
+ // Note: this Javadoc is copied from javax.management.Descriptor
+ // due to 6369229.
+ public boolean equals(Object o) {
+ if (o == this)
+ return true;
+ if (!(o instanceof Descriptor))
+ return false;
+ String[] onames;
+ if (o instanceof ImmutableDescriptor) {
+ onames = ((ImmutableDescriptor) o).names;
+ } else {
+ onames = ((Descriptor) o).getFieldNames();
+ Arrays.sort(onames, String.CASE_INSENSITIVE_ORDER);
+ }
+ if (names.length != onames.length)
+ return false;
+ for (int i = 0; i < names.length; i++) {
+ if (!names[i].equalsIgnoreCase(onames[i]))
+ return false;
+ }
+ Object[] ovalues;
+ if (o instanceof ImmutableDescriptor)
+ ovalues = ((ImmutableDescriptor) o).values;
+ else
+ ovalues = ((Descriptor) o).getFieldValues(onames);
+ return Arrays.deepEquals(values, ovalues);
+ }
+
+ /**
+ * <p>Returns the hash code value for this descriptor. The hash
+ * code is computed as the sum of the hash codes for each field in
+ * the descriptor. The hash code of a field with name {@code n}
+ * and value {@code v} is {@code n.toLowerCase().hashCode() ^ h}.
+ * Here {@code h} is the hash code of {@code v}, computed as
+ * follows:</p>
+ *
+ * <ul>
+ * <li>If {@code v} is null then {@code h} is 0.</li>
+ * <li>If {@code v} is a primitive array then {@code h} is computed using
+ * the appropriate overloading of {@code java.util.Arrays.hashCode}.</li>
+ * <li>If {@code v} is an object array then {@code h} is computed using
+ * {@link Arrays#deepHashCode(Object[])}.</li>
+ * <li>Otherwise {@code h} is {@code v.hashCode()}.</li>
+ * </ul>
+ *
+ * @return A hash code value for this object.
+ *
+ */
+ // Note: this Javadoc is copied from javax.management.Descriptor
+ // due to 6369229.
+ public int hashCode() {
+ if (hashCode == -1) {
+ int hash = 0;
+ for (int i = 0; i < names.length; i++) {
+ Object v = values[i];
+ int h;
+ if (v == null)
+ h = 0;
+ else if (v instanceof Object[])
+ h = Arrays.deepHashCode((Object[]) v);
+ else if (v.getClass().isArray()) {
+ h = Arrays.deepHashCode(new Object[] {v}) - 31;
+ // hashcode of a list containing just v is
+ // v.hashCode() + 31, see List.hashCode()
+ } else
+ h = v.hashCode();
+ hash += names[i].toLowerCase().hashCode() ^ h;
+ }
+ hashCode = hash;
+ }
+ return hashCode;
+ }
+
+ public String toString() {
+ StringBuilder sb = new StringBuilder("{");
+ for (int i = 0; i < names.length; i++) {
+ if (i > 0)
+ sb.append(", ");
+ sb.append(names[i]).append("=");
+ Object v = values[i];
+ if (v != null && v.getClass().isArray()) {
+ String s = Arrays.deepToString(new Object[] {v});
+ s = s.substring(1, s.length() - 1); // remove [...]
+ v = s;
+ }
+ sb.append(String.valueOf(v));
+ }
+ return sb.append("}").toString();
+ }
+
+ /**
+ * Returns true if all of the fields have legal values given their
+ * names. This method always returns true, but a subclass can
+ * override it to return false when appropriate.
+ *
+ * @return true if the values are legal.
+ *
+ * @exception RuntimeOperationsException if the validity checking fails.
+ * The method returns false if the descriptor is not valid, but throws
+ * this exception if the attempt to determine validity fails.
+ */
+ public boolean isValid() {
+ return true;
+ }
+
+ /**
+ * <p>Returns a descriptor which is equal to this descriptor.
+ * Changes to the returned descriptor will have no effect on this
+ * descriptor, and vice versa.</p>
+ *
+ * <p>This method returns the object on which it is called.
+ * A subclass can override it
+ * to return another object provided the contract is respected.
+ *
+ * @exception RuntimeOperationsException for illegal value for field Names
+ * or field Values.
+ * If the descriptor construction fails for any reason, this exception will
+ * be thrown.
+ */
+ public Descriptor clone() {
+ return this;
+ }
+
+ /**
+ * This operation is unsupported since this class is immutable. If
+ * this call would change a mutable descriptor with the same contents,
+ * then a {@link RuntimeOperationsException} wrapping an
+ * {@link UnsupportedOperationException} is thrown. Otherwise,
+ * the behavior is the same as it would be for a mutable descriptor:
+ * either an exception is thrown because of illegal parameters, or
+ * there is no effect.
+ */
+ public final void setFields(String[] fieldNames, Object[] fieldValues)
+ throws RuntimeOperationsException {
+ if (fieldNames == null || fieldValues == null)
+ illegal("Null argument");
+ if (fieldNames.length != fieldValues.length)
+ illegal("Different array sizes");
+ for (int i = 0; i < fieldNames.length; i++)
+ checkIllegalFieldName(fieldNames[i]);
+ for (int i = 0; i < fieldNames.length; i++)
+ setField(fieldNames[i], fieldValues[i]);
+ }
+
+ /**
+ * This operation is unsupported since this class is immutable. If
+ * this call would change a mutable descriptor with the same contents,
+ * then a {@link RuntimeOperationsException} wrapping an
+ * {@link UnsupportedOperationException} is thrown. Otherwise,
+ * the behavior is the same as it would be for a mutable descriptor:
+ * either an exception is thrown because of illegal parameters, or
+ * there is no effect.
+ */
+ public final void setField(String fieldName, Object fieldValue)
+ throws RuntimeOperationsException {
+ checkIllegalFieldName(fieldName);
+ int i = fieldIndex(fieldName);
+ if (i < 0)
+ unsupported();
+ Object value = values[i];
+ if ((value == null) ?
+ (fieldValue != null) :
+ !value.equals(fieldValue))
+ unsupported();
+ }
+
+ /**
+ * Removes a field from the descriptor.
+ *
+ * @param fieldName String name of the field to be removed.
+ * If the field name is illegal or the field is not found,
+ * no exception is thrown.
+ *
+ * @exception RuntimeOperationsException if a field of the given name
+ * exists and the descriptor is immutable. The wrapped exception will
+ * be an {@link UnsupportedOperationException}.
+ */
+ public final void removeField(String fieldName) {
+ if (fieldName != null && fieldIndex(fieldName) >= 0)
+ unsupported();
+ }
+
+ static Descriptor nonNullDescriptor(Descriptor d) {
+ if (d == null)
+ return EMPTY_DESCRIPTOR;
+ else
+ return d;
+ }
+
+ private static void checkIllegalFieldName(String name) {
+ if (name == null || name.equals(""))
+ illegal("Null or empty field name");
+ }
+
+ private static void unsupported() {
+ UnsupportedOperationException uoe =
+ new UnsupportedOperationException("Descriptor is read-only");
+ throw new RuntimeOperationsException(uoe);
+ }
+
+ private static void illegal(String message) {
+ IllegalArgumentException iae = new IllegalArgumentException(message);
+ throw new RuntimeOperationsException(iae);
+ }
+}