--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.management/share/classes/javax/management/AttributeValueExp.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,167 @@
+/*
+ * Copyright (c) 1999, 2015, Oracle and/or its affiliates. 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. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package javax.management;
+
+
+import com.sun.jmx.mbeanserver.Introspector;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+
+/**
+ * <p>Represents attributes used as arguments to relational constraints.
+ * Instances of this class are usually obtained using {@link Query#attr(String)
+ * Query.attr}.</p>
+ *
+ * <p>An <CODE>AttributeValueExp</CODE> may be used anywhere a
+ * <CODE>ValueExp</CODE> is required.
+ *
+ * @since 1.5
+ */
+public class AttributeValueExp implements ValueExp {
+
+
+ /* Serial version */
+ private static final long serialVersionUID = -7768025046539163385L;
+
+ /**
+ * @serial The name of the attribute
+ */
+ private String attr;
+
+ /**
+ * An <code>AttributeValueExp</code> with a null attribute.
+ * @deprecated An instance created with this constructor cannot be
+ * used in a query.
+ */
+ @Deprecated
+ public AttributeValueExp() {
+ }
+
+ /**
+ * Creates a new <CODE>AttributeValueExp</CODE> representing the
+ * specified object attribute, named attr.
+ *
+ * @param attr the name of the attribute whose value is the value
+ * of this {@link ValueExp}.
+ */
+ public AttributeValueExp(String attr) {
+ this.attr = attr;
+ }
+
+ /**
+ * Returns a string representation of the name of the attribute.
+ *
+ * @return the attribute name.
+ */
+ public String getAttributeName() {
+ return attr;
+ }
+
+ /**
+ * <p>Applies the <CODE>AttributeValueExp</CODE> on an MBean.
+ * This method calls {@link #getAttribute getAttribute(name)} and wraps
+ * the result as a {@code ValueExp}. The value returned by
+ * {@code getAttribute} must be a {@code Number}, {@code String},
+ * or {@code Boolean}; otherwise this method throws a
+ * {@code BadAttributeValueExpException}, which will cause
+ * the containing query to be false for this {@code name}.</p>
+ *
+ * @param name The name of the MBean on which the <CODE>AttributeValueExp</CODE> will be applied.
+ *
+ * @return The <CODE>ValueExp</CODE>.
+ *
+ * @throws BadStringOperationException {@inheritDoc}
+ * @throws BadBinaryOpValueExpException {@inheritDoc}
+ * @throws BadAttributeValueExpException {@inheritDoc}
+ * @throws InvalidApplicationException {@inheritDoc}
+ */
+ @Override
+ public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException,
+ BadAttributeValueExpException, InvalidApplicationException {
+ Object result = getAttribute(name);
+
+ if (result instanceof Number) {
+ return new NumericValueExp((Number)result);
+ } else if (result instanceof String) {
+ return new StringValueExp((String)result);
+ } else if (result instanceof Boolean) {
+ return new BooleanValueExp((Boolean)result);
+ } else {
+ throw new BadAttributeValueExpException(result);
+ }
+ }
+
+ /**
+ * Returns the string representing its value.
+ */
+ @Override
+ public String toString() {
+ return attr;
+ }
+
+
+ /**
+ * Sets the MBean server on which the query is to be performed.
+ *
+ * @param s The MBean server on which the query is to be performed.
+ *
+ * @deprecated This method has no effect. The MBean Server used to
+ * obtain an attribute value is {@link QueryEval#getMBeanServer()}.
+ */
+ /* There is no need for this method, because if a query is being
+ evaluted an AttributeValueExp can only appear inside a QueryExp,
+ and that QueryExp will itself have done setMBeanServer. */
+ @Deprecated
+ @Override
+ public void setMBeanServer(MBeanServer s) {
+ }
+
+
+ /**
+ * <p>Return the value of the given attribute in the named MBean.
+ * If the attempt to access the attribute generates an exception,
+ * return null.</p>
+ *
+ * <p>The MBean Server used is the one returned by {@link
+ * QueryEval#getMBeanServer()}.</p>
+ *
+ * @param name the name of the MBean whose attribute is to be returned.
+ *
+ * @return the value of the attribute, or null if it could not be
+ * obtained.
+ */
+ protected Object getAttribute(ObjectName name) {
+ try {
+ // Get the value from the MBeanServer
+
+ MBeanServer server = QueryEval.getMBeanServer();
+
+ return server.getAttribute(name, attr);
+ } catch (Exception re) {
+ return null;
+ }
+ }
+}