-
Notifications
You must be signed in to change notification settings - Fork 14
/
SparqlQueryParser.java
168 lines (155 loc) · 6 KB
/
SparqlQueryParser.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/**
* Copyright (C) 2016 Czech Technical University in Prague
* <p>
* This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later
* version.
* <p>
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details. You should have received a copy of the GNU General Public License along with this program. If not, see
* <http://www.gnu.org/licenses/>.
*/
package cz.cvut.kbss.jopa.query.sparql;
import cz.cvut.kbss.jopa.exception.QueryParserException;
import cz.cvut.kbss.jopa.query.QueryParameter;
import cz.cvut.kbss.jopa.query.QueryParser;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class SparqlQueryParser implements QueryParser {
private String query;
private Map<Object, QueryParameter<?>> uniqueParams;
private Integer positionalCounter;
private List<String> queryParts;
private List<QueryParameter<?>> parameters;
private boolean inParam;
private boolean inSQString; // In apostrophe string (')
private boolean inDQString; // In double-quoted string (")
private int lastParamEndIndex;
private int paramStartIndex;
private ParamType currentParamType;
private enum ParamType {
POSITIONAL, NAMED
}
@Override
public SparqlQueryHolder parseQuery(String query) {
this.query = query;
this.queryParts = new ArrayList<>();
this.uniqueParams = new HashMap<>();
this.positionalCounter = 1;
this.parameters = new ArrayList<>();
this.inSQString = false;
// In double-quoted string
this.inDQString = false;
this.inParam = false;
this.lastParamEndIndex = 0;
this.paramStartIndex = 0;
this.currentParamType = null;
int i;
for (i = 0; i < query.length(); i++) {
final char c = query.charAt(i);
switch (c) {
case '\'':
inSQString = !inSQString;
break;
case '"':
inDQString = !inDQString;
break;
case '$':
parameterStart(i, ParamType.POSITIONAL);
break;
case '?':
if (inParam) {
parameterEnd(i); // Property path zero or one
} else {
parameterStart(i, ParamType.NAMED);
}
break;
// TODO Use an algebra and AST to parse queries
case '<':
case '>':
case ',':
case '\n':
case ')':
case ' ':
case '.':
case ';':
case '{':
case '}':
case '[':
case ']':
case '+':
case '*':
case '/':
case '|':
if (inParam) {
parameterEnd(i);
}
break;
default:
break;
}
}
if (inParam) {
parameterEnd(i);
} else {
queryParts.add(query.substring(lastParamEndIndex));
}
return new SparqlQueryHolder(query, queryParts, parameters);
}
private void parameterStart(int index, ParamType paramType) {
if (!inSQString && !inDQString) {
queryParts.add(query.substring(lastParamEndIndex, index));
paramStartIndex = index + 1;
inParam = true;
this.currentParamType = paramType;
}
}
private void parameterEnd(int index) {
this.lastParamEndIndex = index;
this.inParam = false;
final String param = query.substring(paramStartIndex, index);
parameters.add(resolveParamIdentification(param));
}
private QueryParameter<?> resolveParamIdentification(String identification) {
final QueryParameter<?> queryParameter;
if (identification.isEmpty()) {
if (currentParamType == ParamType.POSITIONAL) {
queryParameter = getQueryParameter(positionalCounter++);
} else {
throw new QueryParserException("Missing parameter name in query " + query);
}
} else {
if (currentParamType == ParamType.POSITIONAL) {
try {
Integer position = Integer.parseInt(identification);
positionalCounter++;
queryParameter = getQueryParameter(position);
} catch (NumberFormatException e) {
throw new QueryParserException(identification + " is not a valid parameter position.", e);
}
} else {
queryParameter = getQueryParameter(identification);
}
}
return queryParameter;
}
private QueryParameter<?> getQueryParameter(String name) {
// We want to reuse the param instances, so that changes to them apply throughout the whole query
if (!uniqueParams.containsKey(name)) {
uniqueParams.put(name, new QueryParameter<>(name));
}
return uniqueParams.get(name);
}
private QueryParameter<?> getQueryParameter(Integer position) {
// We want to reuse the param instances, so that changes to them apply throughout the whole query
if (uniqueParams.containsKey(position)) {
throw new QueryParserException("Parameter with position " + position + " already found in query " + query);
}
final QueryParameter<?> qp = new QueryParameter<>(position);
uniqueParams.put(position, qp);
return qp;
}
}