MonitoredAttributeBase.java revision 608:7e06bf1dcb09 
1/*
2 * Copyright (c) 2003, Oracle and/or its affiliates. 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.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 * questions.
24 */
25package com.sun.corba.se.spi.monitoring;
26
27import java.util.*;
28
29/**
30 * <p>
31 *
32 * @author Hemanth Puttaswamy
33 * </p>
34 * <p>
35 *  A Convenient class provided to help users extend and implement only
36 *  getValue(), if there is no need to clear the state and the attribute is not
37 *  writable.
38 *
39 * </p>
40 */
41public abstract class MonitoredAttributeBase implements MonitoredAttribute {
42    String name;
43    MonitoredAttributeInfo attributeInfo;
44    /**
45     * Constructor.
46     */
47    public MonitoredAttributeBase( String name, MonitoredAttributeInfo info ) {
48        this.name = name;
49        this.attributeInfo = info;
50    }
51
52
53    /**
54     * A Package Private Constructor for internal use only.
55     */
56    MonitoredAttributeBase( String name ) {
57        this.name = name;
58    }
59
60
61    /**
62     * A Package Private convenience method for setting MonitoredAttributeInfo
63     * for this Monitored Attribute.
64     */
65    void setMonitoredAttributeInfo( MonitoredAttributeInfo info ) {
66        this.attributeInfo = info;
67    }
68
69    /**
70     *  If the concrete class decides not to provide the implementation of this
71     *  method, then it's OK. Some of the  examples where we may decide to not
72     *  provide the implementation is the connection state. Irrespective of
73     *  the call to clearState, the connection state will be showing the
74     *  currect state of the connection.
75     *  NOTE: This method is only used to clear the Monitored Attribute state,
76     *  not the real state of the system itself.
77     */
78    public void clearState( ) {
79    }
80
81    /**
82     *  This method should be implemented by the concrete class.
83     */
84    public abstract Object getValue( );
85
86    /**
87     *  This method should be implemented by the concrete class only if the
88     *  attribute is writable. If the attribute is not writable and if this
89     *  method called, it will result in an IllegalStateException.
90     */
91    public void setValue( Object value ) {
92        if( !attributeInfo.isWritable() ) {
93            throw new IllegalStateException(
94                "The Attribute " + name + " is not Writable..." );
95        }
96        throw new IllegalStateException(
97            "The method implementation is not provided for the attribute " +
98            name );
99    }
100
101
102    /**
103     *  Gets the MonitoredAttributeInfo for the attribute.
104     */
105    public MonitoredAttributeInfo getAttributeInfo( ) {
106        return attributeInfo;
107    }
108
109    /**
110     * Gets the name of the attribute.
111     */
112    public String getName( ) {
113        return name;
114    }
115} // end MonitoredAttributeBase
116