01: /*
02: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
03: *
04: * This file is part of Resin(R) Open Source
05: *
06: * Each copy or derived work must preserve the copyright notice and this
07: * notice unmodified.
08: *
09: * Resin Open Source is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 2 of the License, or
12: * (at your option) any later version.
13: *
14: * Resin Open Source is distributed in the hope that it will be useful,
15: * but WITHOUT ANY WARRANTY; without even the implied warranty of
16: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17: * of NON-INFRINGEMENT. See the GNU General Public License for more
18: * details.
19: *
20: * You should have received a copy of the GNU General Public License
21: * along with Resin Open Source; if not, write to the
22: * Free SoftwareFoundation, Inc.
23: * 59 Temple Place, Suite 330
24: * Boston, MA 02111-1307 USA
25: *
26: * @author Scott Ferguson
27: */
28:
29: package com.caucho.db.sql;
30:
31: import com.caucho.log.Log;
32:
33: import java.sql.SQLException;
34: import java.util.ArrayList;
35: import java.util.logging.Logger;
36:
37: class StringExpr extends Expr {
38: private static final Logger log = Log.open(StringExpr.class);
39:
40: private String _value;
41:
42: StringExpr(String value) {
43: _value = value;
44: }
45:
46: /**
47: * Returns the value.
48: */
49: public String getValue() {
50: return _value;
51: }
52:
53: /**
54: * Returns the type of the expression.
55: */
56: public Class getType() {
57: return String.class;
58: }
59:
60: /**
61: * Returns the cost based on the given FromList.
62: */
63: public long subCost(ArrayList<FromItem> fromList) {
64: return 0;
65: }
66:
67: /**
68: * Returns true if the literal is null.
69: */
70: public boolean isNull(QueryContext context) throws SQLException {
71: return _value == null;
72: }
73:
74: /**
75: * Evaluates the literal as a string.
76: */
77: public String evalString(QueryContext context) throws SQLException {
78: return _value;
79: }
80:
81: public String toString() {
82: return "'" + _value + "'";
83: }
84: }
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