1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17 package org.apache.commons.configuration.beanutils;
18
19 import java.util.Map;
20
21 /***
22 * <p>
23 * Definition of an interface for declaring a bean in a configuration file.
24 * </p>
25 * <p>
26 * Commons Configurations allows to define beans (i.e. simple Java objects) in
27 * configuration files, which can be created at runtime. This is especially
28 * useful if you program against interfaces and want to define the concrete
29 * implementation class is a configuration file.
30 * </p>
31 * <p>
32 * This interface defines methods for retrieving all information about a bean
33 * that should be created from a configuration file, e.g. the bean's properties
34 * or the factory to use for creating the instance. With different
35 * implementations different "layouts" of bean declarations can be
36 * supported. For instance if an XML configuration file is used, all features of
37 * XML (e.g. attributes, nested elements) can be used to define the bean. In a
38 * properties file the declaration format is more limited. The purpose of this
39 * interface is to abstract from the concrete declaration format.
40 * </p>
41 *
42 * @since 1.3
43 * @author Oliver Heger
44 * @version $Id: BeanDeclaration.java 439648 2006-09-02 20:42:10Z oheger $
45 */
46 public interface BeanDeclaration
47 {
48 /***
49 * Returns the name of the <code>BeanFactory</code> that should be used
50 * for creating the bean instance. This can be <b>null</b>, then a default
51 * factory will be used.
52 *
53 * @return the name of the bean factory
54 */
55 String getBeanFactoryName();
56
57 /***
58 * Here an arbitrary object can be returned that will be passed to the bean
59 * factory. Its meaning is not further specified. The purpose of this
60 * additional parameter is to support a further configuration of the bean
61 * factory that can be placed directly at the bean declaration.
62 *
63 * @return a parameter for the bean factory
64 */
65 Object getBeanFactoryParameter();
66
67 /***
68 * Returns the name of the bean class, from which an instance is to be
69 * created. This value must be defined unless a default class is provided
70 * for the bean creation operation.
71 *
72 * @return the name of the bean class
73 */
74 String getBeanClassName();
75
76 /***
77 * Returns a map with properties that should be initialized on the newly
78 * created bean. The map's keys are the names of the properties; the
79 * corresponding values are the properties' values. The return value can be
80 * <b>null</b> if no properties should be set.
81 *
82 * @return a map with properties to be initialized
83 */
84 Map getBeanProperties();
85
86 /***
87 * Returns a map with declarations for beans that should be set as
88 * properties of the newly created bean. This allows for complex
89 * initialization szenarios: a bean for a bean that contains complex
90 * properties (e.g. other beans) can have nested declarations for defining
91 * these complex properties. The returned map's key are the names of the
92 * properties to initialze. The values are <code>BeanDeclaration</code>
93 * implementations. They will be treated like this declaration (in a
94 * recursive manner), and the resulting beans are assigned to the
95 * corresponding properties.
96 *
97 * @return a map with nested bean declarations
98 */
99 Map getNestedBeanDeclarations();
100 }