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16 package org.outerj.daisy.query.model.functions;
17
18 import org.outerj.daisy.repository.Document;
19 import org.outerj.daisy.repository.Version;
20 import org.outerj.daisy.repository.query.QueryException;
21 import org.outerj.daisy.repository.query.EvaluationContext;
22 import org.outerj.daisy.query.QueryContext;
23 import org.outerj.daisy.query.model.*;
24
25 import java.util.Locale  ;
26 import java.util.Iterator ;
27 import java.sql.PreparedStatement ;
28 import java.sql.SQLException ;
29
30 public class ConcatFunction extends AbstractFunction {
31 public static final String NAME = "Concat";
32
33 public String getFunctionName() {
34 return NAME;
35 }
36
37 public void prepare(QueryContext context) throws QueryException {
38 super.prepare(context);
39 if (params.size() < 1)
40 throw new QueryException(NAME + " requires at least one argument.");
41
42 Iterator paramsIt = params.iterator();
43 while (paramsIt.hasNext()) {
44 ValueExpr valueExpr = (ValueExpr)paramsIt.next();
45 if ((valueExpr.getValueType() != QValueType.STRING && valueExpr.getValueType() != QValueType.UNDEFINED) || valueExpr.isSymbolicIdentifier() || valueExpr.isMultiValue())
46 throw new QueryException(NAME + " has invalid arguments (only strings allowed).");
47 }
48 }
49
50 public void generateSqlValueExpr(StringBuffer sql, SqlGenerationContext context) throws QueryException {
51 String [] sqlFunction = context.getJdbcHelper().getStringConcatFunction();
52 sql.append(' ').append(sqlFunction[0]).append(' ');
53 super.generateSqlValueExpr(sql, context);
54 sql.append(sqlFunction[1]).append(' ');
55 }
56
57 public int bindValueExpr(PreparedStatement stmt, int bindPos, QValueType valueType, EvaluationContext evaluationContext) throws SQLException , QueryException {
58 return super.bindValueExpr(stmt, bindPos, QValueType.STRING, evaluationContext);
59 }
60
61 public Object evaluate(QValueType valueType, EvaluationContext evaluationContext) throws QueryException {
62 StringBuffer result = new StringBuffer ();
63 Iterator paramsIt = params.iterator();
64 while (paramsIt.hasNext()) {
65 ValueExpr valueExpr = (ValueExpr)paramsIt.next();
66 result.append(valueExpr.evaluate(QValueType.STRING, evaluationContext));
67 }
68 return result.toString();
69 }
70
71 public Object evaluate(QValueType valueType, Document document, Version version, EvaluationContext evaluationContext) throws QueryException {
72 StringBuffer result = new StringBuffer ();
73 Iterator paramsIt = params.iterator();
74 while (paramsIt.hasNext()) {
75 ValueExpr valueExpr = (ValueExpr)paramsIt.next();
76 result.append(valueExpr.evaluate(QValueType.STRING, document, version, evaluationContext));
77 }
78 return result.toString();
79 }
80
81 public QValueType getValueType() {
82 return QValueType.STRING;
83 }
84
85 public String getTitle(Locale locale) {
86 return getExpression();
87 }
88
89 public QValueType getOutputValueType() {
90 return QValueType.STRING;
91 }
92
93 public Object getOutputValue(Document document, Version version, EvaluationContext evaluationContext) throws QueryException {
94 return evaluate(null, document, version, evaluationContext);
95 }
96 }
97 |
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