Source Code Cross Referenced for StepField.java in  » Database-ORM » MMBase » org » mmbase » storage » search » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:
03:        This software is OSI Certified Open Source Software.
04:        OSI Certified is a certification mark of the Open Source Initiative.
05:
06:        The license (Mozilla version 1.0) can be read at the MMBase site.
07:        See http://www.MMBase.org/license
08:
09:         */
10:        package org.mmbase.storage.search;
11:
12:        /**
13:         * A stepfield refers to a field in a step.
14:         *  Each stepfield has an unique alias to identify it.
15:         * <p>
16:         * This corresponds to a prefixed fieldname in a SQL SELECT-syntax.
17:         *
18:         * @author Rob van Maris
19:         * @version $Id: StepField.java,v 1.6 2007/12/06 08:13:36 michiel Exp $
20:         * @since MMBase-1.7
21:         */
22:        public interface StepField {
23:            /**
24:             * Gets the name of the associated field (without prefix).
25:             * <p>
26:             * This corresponds to the fieldname in SQL SELECT-syntax.
27:             */
28:            String getFieldName();
29:
30:            /**
31:             * Gets the alias for the associated field.
32:             * <p>
33:             * This corresponds to the field alias in SQL SELECT-syntax.
34:             */
35:            String getAlias();
36:
37:            /**
38:             * Gets the step associated with this fieldstep.
39:             */
40:            Step getStep();
41:
42:            /**
43:             * Gets the type of the associated field.
44:             * This is one of the values defined in {@link org.mmbase.bridge.Field Field}.
45:             */
46:            int getType();
47:
48:            /**
49:             * Compares this stepfield to the specified object. The result is
50:             * <code>true</code> if and only if the argument is a non-null
51:             * StepField object associated with the same field, using the same alias.
52:             *
53:             * @param obj The object to compare with.
54:             * @return <code>true</code> if the objects are equal,
55:             * <code>false</code> otherwise.
56:             */
57:            public boolean equals(Object obj);
58:
59:            // javadoc is inherited
60:            public int hashCode();
61:
62:            /**
63:             * Returns a string representation of this StepField.
64:             * The string representation has the form
65:             * "StepField(step:&lt;step&gt;, fieldname:&lt;fieldname&gt;, alias:&lt;alias&gt;)"
66:             * where
67:             * <ul>
68:             * <li><em>&lt;step&gt;</em> is the step alias returned by
69:             *     <code>getStep().getAlias()</code> or,
70:             *     when the step alias is <code>null</code>, the step tablename
71:             *     returned by <code>getStep().getTableName()</code>.
72:             * <li><em>&lt;fieldname&gt;</em> is the fieldname returned by
73:             *     {@link #getFieldName getFieldName()}
74:             * <li><em>&lt;alias&gt;</em> is the alias returned by {@link #getAlias getAlias()}
75:             * </ul>
76:             *
77:             * @return A string representation of this StepField.
78:             */
79:            public String toString();
80:
81:        }