001: package org.apache.ojb.jdo.jdoql;
002:
003: /* Copyright 2003-2005 The Apache Software Foundation
004: *
005: * Licensed under the Apache License, Version 2.0 (the "License");
006: * you may not use this file except in compliance with the License.
007: * You may obtain a copy of the License at
008: *
009: * http://www.apache.org/licenses/LICENSE-2.0
010: *
011: * Unless required by applicable law or agreed to in writing, software
012: * distributed under the License is distributed on an "AS IS" BASIS,
013: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014: * See the License for the specific language governing permissions and
015: * limitations under the License.
016: */
017:
018: /**
019: * Encapsulates a variable local to the JDOQL query. This can be either a
020: * variable or a parameter. Variables must be at some point bound to values
021: * either directly by the user of the query (if a parameter) or during
022: * evaluation of the query.
023: *
024: * @author <a href="mailto:tomdz@apache.org">Thomas Dudziak</a>
025: */
026: public class LocalVariable extends QueryTreeNode {
027: /** The name of the variable */
028: private String _name;
029: /** The type of the variable */
030: private Type _type;
031: /** Whether this variable is already bound to a value */
032: private boolean _isBound = false;
033: /** The value of the variable */
034: private Object _value;
035:
036: /**
037: * Creates a new variable object.
038: *
039: * @param type The type of the variable
040: * @param name The name of the variable
041: */
042: public LocalVariable(Type type, String name) {
043: _type = type;
044: _name = name;
045: }
046:
047: /**
048: * Returns the type of the variable.
049: *
050: * @return The type
051: */
052: public Type getType() {
053: return _type;
054: }
055:
056: /**
057: * Returns the value of this variable
058: *
059: * @return The value
060: */
061: public Object getValue() {
062: return _value;
063: }
064:
065: /**
066: * Sets the value of the variable.
067: *
068: * @param value The value
069: */
070: public void setValue(Object value) {
071: _value = value;
072: _isBound = true;
073: }
074:
075: /**
076: * Returns whether this variable is bound to a value.
077: *
078: * @return <code>true</code> if the variable has a value
079: */
080: public boolean isBound() {
081: return _isBound;
082: }
083:
084: /**
085: * Returns the name of the variable.
086: *
087: * @return The name
088: */
089: public String getName() {
090: return _name;
091: }
092:
093: /* (non-Javadoc)
094: * @see org.apache.ojb.jdo.jdoql.Acceptor#accept(org.apache.ojb.jdo.jdoql.Visitor)
095: */
096: public void accept(Visitor visitor) {
097: visitor.visit(this );
098: }
099:
100: /* (non-Javadoc)
101: * @see java.lang.Object#toString()
102: */
103: public String toString() {
104: return _type.toString() + " " + _name;
105: }
106: }
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