|
1 package com.tonbeller.wcf.param;
2
3 import java.util.ArrayList  ;
4 import java.util.HashMap ;
5 import java.util.Iterator ;
6 import java.util.List ;
7 import java.util.Map ;
8
9 import com.tonbeller.wcf.utils.SqlUtils;
10
11
15 public class SqlGenerator implements SqlExprVisitor {
16 StringBuffer sb;
17 Map columnMap;
18
19
22 public static final String DEFAULT_COLUMN_ID = "DEFAULT_COLUMN_ID";
23
24 public SqlGenerator() {
25 this.columnMap = new HashMap ();
26 }
27
28
31 public SqlGenerator(String defaultColumn) {
32 this.columnMap = new HashMap ();
33 columnMap.put(DEFAULT_COLUMN_ID, defaultColumn);
34 }
35
36 public SqlGenerator(Map columnMap) {
37 this.columnMap = columnMap;
38 }
39
40
43 protected SqlGenerator copyGenerator() {
44 return new SqlGenerator(columnMap);
45 }
46
47
50 protected String generateOpd(SqlExpr opd) {
51 return copyGenerator().generate(opd);
52 }
53
54 protected String getColumnName(SqlColumnConstraint scc) {
55 String columnId = scc.getColumnId();
56 if (columnId == null)
57 columnId = DEFAULT_COLUMN_ID;
58 String qname = (String ) columnMap.get(columnId);
59 if (qname != null)
60 return qname;
61 return columnId;
62 }
63
64 public void genAndOr(SqlExprWithOperands exp, String keyword) {
65 Iterator it = exp.getOperands().iterator();
66 SqlExpr opd = (SqlExpr) it.next();
67 sb.append("(");
68 sb.append(generateOpd(opd));
69 while (it.hasNext()) {
70 sb.append(" ");
71 sb.append(keyword);
72 sb.append(" ");
73 opd = (SqlExpr) it.next();
74 sb.append(generateOpd(opd));
75 }
76 sb.append(")");
77 }
78
79 public void visitSqlAndExpr(SqlAndExpr exp) {
80 genAndOr(exp, "AND");
81 }
82
83 public void visitSqlOrExpr(SqlOrExpr exp) {
84 genAndOr(exp, "OR");
85 }
86
87 public void visitSqlBetweenExpr(SqlBetweenExpr exp) {
88 sb.append(getColumnName(exp));
89 sb.append(" BETWEEN ");
90 sb.append(SqlUtils.escapeSql(exp.getFirst()));
91 sb.append(" AND ");
92 sb.append(SqlUtils.escapeSql(exp.getLast()));
93 }
94
95 public void visitSqlEqualExpr(SqlEqualExpr exp) {
96 generateEquals(exp, exp.getSqlValue());
97 }
98
99 private void generateEquals(SqlColumnConstraint exp, Object sqlValue) {
100 sb.append(getColumnName(exp));
101 if (sqlValue == null)
102 sb.append(" IS NULL");
103 else {
104 sb.append(" = ");
105 sb.append(SqlUtils.escapeSql(sqlValue));
106 }
107 }
108
109 public void visitSqlDummyExpr(SqlDummyExpr exp) {
110 sb.append("1 = 1");
111 }
112
113 public void visitSqlInExpr(SqlInExpr exp) {
114 Object [] values = exp.getSqlValues();
115
116 String cname = getColumnName(exp);
117 boolean containsNull = containsNull(values);
118 if (containsNull)
119 values = removeNulls(values);
120
121 if (values.length == 0) {
122 if (containsNull)
124 sb.append(cname).append(" IS NULL");
125 else
126 sb.append("1=0");
127 } else if (values.length == 1) {
128 if (containsNull) {
130 sb.append("(");
131 sb.append(cname);
132 sb.append(" = ");
133 sb.append(SqlUtils.escapeSql(values[0]));
134 sb.append(" OR ");
135 sb.append(cname);
136 sb.append(" IS NULL)");
137 } else {
138 sb.append(cname);
139 sb.append(" = ");
140 sb.append(SqlUtils.escapeSql(values[0]));
141 }
142 } else {
143 String list = generateList(values);
145 if (containsNull) {
146 sb.append("(");
147 sb.append(cname);
148 sb.append(" IN (");
149 sb.append(list);
150 sb.append(") OR ");
151 sb.append(cname);
152 sb.append(" IS NULL)");
153 } else {
154 sb.append(cname);
155 sb.append(" IN (");
156 sb.append(list);
157 sb.append(")");
158 }
159 }
160 }
161
162 protected String generateList(Object [] values) {
163 StringBuffer list = new StringBuffer ();
164 for (int i = 0; i < values.length; i++) {
165 if (i > 0)
166 list.append(", ");
167 list.append(SqlUtils.escapeSql(values[i]));
168 }
169 return list.toString();
170 }
171
172 protected Object [] removeNulls(Object [] values) {
173 List list = new ArrayList ();
174 for (int i = 0; i < values.length; i++) {
175 if (values[i] != null)
176 list.add(values[i]);
177 }
178 return list.toArray();
179 }
180
181 protected boolean containsNull(Object [] values) {
182 for (int i = 0; i < values.length; i++)
183 if (values[i] == null)
184 return true;
185 return false;
186 }
187
188
191 public String generate(SqlExpr sqlExpr) {
192 sb = new StringBuffer ();
193 sqlExpr.accept(this);
194 return sb.toString();
195 }
196
197
200 public Map getColumnMap() {
201 return columnMap;
202 }
203
204
207 public void setColumnMap(Map columnMap) {
208 this.columnMap = columnMap;
209 }
210
211 } |
Popular Tags |
Java API By Example, From Geeks To Geeks.