MonitoredAttributeBase.java revision 672:2bb058ce572e 
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
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25package com.sun.corba.se.spi.monitoring;
26
27import java.util.*;
28
29/**
30 * @author Hemanth Puttaswamy
31 *
32 *  A Convenient class provided to help users extend and implement only
33 *  getValue(), if there is no need to clear the state and the attribute is not
34 *  writable.
35 */
36public abstract class MonitoredAttributeBase implements MonitoredAttribute {
37    String name;
38    MonitoredAttributeInfo attributeInfo;
39    /**
40     * Constructor.
41     */
42    public MonitoredAttributeBase( String name, MonitoredAttributeInfo info ) {
43        this.name = name;
44        this.attributeInfo = info;
45    }
46
47
48    /**
49     * A Package Private Constructor for internal use only.
50     */
51    MonitoredAttributeBase( String name ) {
52        this.name = name;
53    }
54
55
56    /**
57     * A Package Private convenience method for setting MonitoredAttributeInfo
58     * for this Monitored Attribute.
59     */
60    void setMonitoredAttributeInfo( MonitoredAttributeInfo info ) {
61        this.attributeInfo = info;
62    }
63
64    /**
65     *  If the concrete class decides not to provide the implementation of this
66     *  method, then it's OK. Some of the  examples where we may decide to not
67     *  provide the implementation is the connection state. Irrespective of
68     *  the call to clearState, the connection state will be showing the
69     *  currect state of the connection.
70     *  NOTE: This method is only used to clear the Monitored Attribute state,
71     *  not the real state of the system itself.
72     */
73    public void clearState( ) {
74    }
75
76    /**
77     *  This method should be implemented by the concrete class.
78     */
79    public abstract Object getValue( );
80
81    /**
82     *  This method should be implemented by the concrete class only if the
83     *  attribute is writable. If the attribute is not writable and if this
84     *  method called, it will result in an IllegalStateException.
85     */
86    public void setValue( Object value ) {
87        if( !attributeInfo.isWritable() ) {
88            throw new IllegalStateException(
89                "The Attribute " + name + " is not Writable..." );
90        }
91        throw new IllegalStateException(
92            "The method implementation is not provided for the attribute " +
93            name );
94    }
95
96
97    /**
98     *  Gets the MonitoredAttributeInfo for the attribute.
99     */
100    public MonitoredAttributeInfo getAttributeInfo( ) {
101        return attributeInfo;
102    }
103
104    /**
105     * Gets the name of the attribute.
106     */
107    public String getName( ) {
108        return name;
109    }
110} // end MonitoredAttributeBase
111