1 /*
2 * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package javax.management;
27
28
29 /**
30 * This class is used by the query building mechanism for isInstanceOf expressions.
31 * @serial include
32 *
33 * @since 1.6
34 */
35 class InstanceOfQueryExp extends QueryEval implements QueryExp {
36
37 /* Serial version */
38 private static final long serialVersionUID = -1081892073854801359L;
39
40 /**
41 * @serial The {@link StringValueExp} returning the name of the class
42 * of which selected MBeans should be instances.
43 */
44 private StringValueExp classNameValue;
45
46 /**
47 * Creates a new InstanceOfExp with a specific class name.
48 * @param classNameValue The {@link StringValueExp} returning the name of
49 * the class of which selected MBeans should be instances.
50 */
51 // We are using StringValueExp here to be consistent with other queries,
52 // although we should actually either use a simple string (the classname)
53 // or a ValueExp - which would allow more complex queries - like for
54 // instance evaluating the class name from an AttributeValueExp.
55 // As it stands - using StringValueExp instead of a simple constant string
56 // doesn't serve any useful purpose besides offering a consistent
57 // look & feel.
58 public InstanceOfQueryExp(StringValueExp classNameValue) {
59 if (classNameValue == null) {
60 throw new IllegalArgumentException("Null class name.");
61 }
62
63 this.classNameValue = classNameValue;
64 }
65
66 /**
67 * Returns the class name.
68 * @returns The {@link StringValueExp} returning the name of
69 * the class of which selected MBeans should be instances.
70 */
71 public StringValueExp getClassNameValue() {
72 return classNameValue;
73 }
74
75 /**
76 * Applies the InstanceOf on a MBean.
77 *
78 * @param name The name of the MBean on which the InstanceOf will be applied.
79 *
80 * @return True if the MBean specified by the name is instance of the class.
81 * @exception BadAttributeValueExpException
82 * @exception InvalidApplicationException
83 * @exception BadStringOperationException
84 * @exception BadBinaryOpValueExpException
85 */
86 public boolean apply(ObjectName name)
87 throws BadStringOperationException,
88 BadBinaryOpValueExpException,
89 BadAttributeValueExpException,
90 InvalidApplicationException {
91
92 // Get the class name value
93 final StringValueExp val;
94 try {
95 val = (StringValueExp) classNameValue.apply(name);
96 } catch (ClassCastException x) {
97 // Should not happen - unless someone wrongly implemented
98 // StringValueExp.apply().
99 final BadStringOperationException y =
100 new BadStringOperationException(x.toString());
101 y.initCause(x);
102 throw y;
103 }
104
105 // Test whether the MBean is an instance of that class.
106 try {
107 return getMBeanServer().isInstanceOf(name, val.getValue());
108 } catch (InstanceNotFoundException infe) {
109 return false;
110 }
111 }
112
113 /**
114 * Returns a string representation of this InstanceOfQueryExp.
115 * @return a string representation of this InstanceOfQueryExp.
116 */
117 public String toString() {
118 return "InstanceOf " + classNameValue.toString();
119 }
120 }
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