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Java > Open Source Codes > com > sleepycat > persist > model > ClassMetadata


1 /*-
2  * See the file LICENSE for redistribution information.
3  *
4  * Copyright (c) 2002,2006 Oracle. All rights reserved.
5  *
6  * $Id: ClassMetadata.java,v 1.11 2006/12/05 01:35:37 mark Exp $
7  */
8
9 package com.sleepycat.persist.model;
10
11 import java.io.Serializable JavaDoc;
12 import java.util.List JavaDoc;
13 import java.util.Map JavaDoc;
14
15 /**
16  * The metadata for a persistent class. A persistent class may be specified
17  * with the {@link Entity} or {@link Persistent} annotation.
18  *
19  * <p>{@code ClassMetadata} objects are thread-safe. Multiple threads may
20  * safely call the methods of a shared {@code ClassMetadata} object.</p>
21  *
22  * <p>This and other metadata classes are classes rather than interfaces to
23  * allow adding properties to the model at a future date without causing
24  * incompatibilities. Any such property will be given a default value and
25  * its use will be optional.</p>
26  *
27  * @author Mark Hayes
28  */
29 public class ClassMetadata implements Serializable JavaDoc {
30
31     private static final long serialVersionUID = -2520207423701776679L;
32
33     private String JavaDoc className;
34     private int version;
35     private String JavaDoc proxiedClassName;
36     private boolean entityClass;
37     private PrimaryKeyMetadata primaryKey;
38     private Map JavaDoc<String JavaDoc,SecondaryKeyMetadata> secondaryKeys;
39     private List JavaDoc<FieldMetadata> compositeKeyFields;
40
41     /**
42      * Used by an {@code EntityModel} to construct persistent class metadata.
43      */
44     public ClassMetadata(String JavaDoc className,
45                          int version,
46                          String JavaDoc proxiedClassName,
47                          boolean entityClass,
48                          PrimaryKeyMetadata primaryKey,
49                          Map JavaDoc<String JavaDoc,SecondaryKeyMetadata> secondaryKeys,
50                          List JavaDoc<FieldMetadata> compositeKeyFields) {
51         this.className = className;
52         this.version = version;
53         this.proxiedClassName = proxiedClassName;
54         this.entityClass = entityClass;
55         this.primaryKey = primaryKey;
56         this.secondaryKeys = secondaryKeys;
57         this.compositeKeyFields = compositeKeyFields;
58     }
59
60     /**
61      * Returns the name of the persistent class.
62      */
63     public String JavaDoc getClassName() {
64         return className;
65     }
66
67     /**
68      * Returns the version of this persistent class. This may be specified
69      * using the {@link Entity#version} or {@link Persistent#version}
70      * annotation.
71      */
72     public int getVersion() {
73         return version;
74     }
75
76     /**
77      * Returns the class name of the proxied class if this class is a {@link
78      * PersistentProxy}, or null otherwise.
79      */
80     public String JavaDoc getProxiedClassName() {
81         return proxiedClassName;
82     }
83
84     /**
85      * Returns whether this class is an entity class.
86      */
87     public boolean isEntityClass() {
88         return entityClass;
89     }
90
91     /**
92      * Returns the primary key metadata for a key declared in this class, or
93      * null if none is declared. This may be specified using the {@link
94      * PrimaryKey} annotation.
95      */
96     public PrimaryKeyMetadata getPrimaryKey() {
97         return primaryKey;
98     }
99
100     /**
101      * Returns an unmodifiable map of field name to secondary key metadata for
102      * all secondary keys declared in this class, or null if no secondary keys
103      * are declared in this class. This metadata may be specified using {@link
104      * SecondaryKey} annotations.
105      */
106     public Map JavaDoc<String JavaDoc,SecondaryKeyMetadata> getSecondaryKeys() {
107         return secondaryKeys;
108     }
109
110     /**
111      * Returns an unmodifiable list of metadata for the fields making up a
112      * composite key, or null if this is a not a composite key class. The
113      * order of the fields in the returned list determines their stored order
114      * and may be specified using the {@link KeyField} annotation. When the
115      * composite key class does not implement {@link Comparable}, the order of
116      * the fields is the relative sort order.
117      */
118     public List JavaDoc<FieldMetadata> getCompositeKeyFields() {
119         return compositeKeyFields;
120     }
121
122     @Override JavaDoc
123     public boolean equals(Object JavaDoc other) {
124         if (other instanceof ClassMetadata) {
125             ClassMetadata o = (ClassMetadata) other;
126             return version == o.version &&
127                    entityClass == o.entityClass &&
128                    nullOrEqual(className, o.className) &&
129                    nullOrEqual(proxiedClassName, o.proxiedClassName) &&
130                    nullOrEqual(primaryKey, o.primaryKey) &&
131                    nullOrEqual(secondaryKeys, o.secondaryKeys) &&
132                    nullOrEqual(compositeKeyFields, o.compositeKeyFields);
133         } else {
134             return false;
135         }
136     }
137
138     @Override JavaDoc
139     public int hashCode() {
140         return version +
141                (entityClass ? 1 : 0) +
142                hashCode(className) +
143                hashCode(proxiedClassName) +
144                hashCode(primaryKey) +
145                hashCode(secondaryKeys) +
146                hashCode(compositeKeyFields);
147     }
148
149     static boolean nullOrEqual(Object JavaDoc o1, Object JavaDoc o2) {
150         if (o1 == null) {
151             return o2 == null;
152         } else {
153             return o1.equals(o2);
154         }
155     }
156
157     static int hashCode(Object JavaDoc o) {
158         if (o != null) {
159             return o.hashCode();
160         } else {
161             return 0;
162         }
163     }
164 }
165
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