xlSql


1   /*(Header: NiLOSTEP / xlSQL)
2   
3       Copyright (C) 2004 NiLOSTEP Information Sciences, all 
4       rights reserved.
5       
6       This program is licensed under the terms of the GNU 
7       General Public License.You should have received a copy 
8       of the GNU General Public License along with this 
9       program;
10  */
11  
12  package com.nilostep.xlsql.sql;
13  
14  import com.nilostep.xlsql.database.*;
15  
16  import java.sql.*;
17  import java.util.regex.*;
18  
19  /**
20   * xlSql class translates SQL to native xlSQL
21   * 
22   * @author Jim Caprioli
23   */
24  public abstract class xlSql {
25      //~ Instance variables �����������������������������������������������������
26  
27      protected final String   DOT = ".";
28      protected final int INSERT = 0;
29      protected final int UPDATE = 1;
30      protected final int DELETE = 2;
31      protected final int CREATE_TABLE = 3;
32      protected final int DROP_TABLE = 4;
33      protected final int RENAME_TABLE = 5;
34      protected final int ALTER_TABLE = 6;
35      protected com.nilostep.xlsql.database.xlDatabase db;
36      protected String  [] cmd;
37      
38      /**
39       * Creates a new instance of type xlSql.
40       *
41       * @param database xlSQL instance
42       */
43      public xlSql(com.nilostep.xlsql.database.xlDatabase database) {
44          if (database == null) {
45              throw new NullPointerException  ("xlSQL: database null");
46          } else {
47              db = database;
48          }
49      }
50  
51      /**
52       * Translate foreign SQL string to xlSQL Command
53       *
54       * @param sql foreign SQL string
55       *
56       * @return native xlSQL command object
57       */
58      public xlSqlCommand parseSql(String   sql) {
59          if (sql == null) {
60              throw new NullPointerException  ("xlSQL: sql string null");
61          }
62  
63          xlSqlCommand command;
64  
65          String   sqlLine=sql.replaceAll("\\n|\\r"," "); // add [Tab] \t ?        
66          int cmd = getCmd(sqlLine);
67          String  [] v = getVars(cmd, sqlLine);
68  
69          switch (cmd) {
70  
71              case INSERT:
72                  command = new xlSqlInsert(db, v[0], v[1]);
73                  break;
74  
75              case UPDATE:
76                  command = new xlSqlUpdate(db, v[0], v[1]);
77                  break;
78  
79              case DELETE:
80                  command = new xlSqlDelete(db, v[0], v[1]);
81                  break;
82  
83              case CREATE_TABLE:
84                  command = new xlSqlCreateTable(db, v[0], v[1]);
85                  break;
86  
87              case DROP_TABLE:
88                  command = new xlSqlDropTable(db, v[0], v[1]);
89                  break;
90  
91              case RENAME_TABLE:
92                  command = new xlSqlRenameTable(db, v[0], v[1], v[2], v[3]);
93                  break;
94  
95              case ALTER_TABLE:
96                  command = new xlSqlAlterTable(db, v[0], v[1]);
97                  break;
98  
99              default:
100                 command = new xlSqlNull();
101                 break;
102         }
103         return command;
104     }
105 
106     protected int getCmd(String   sql) {
107         int i;
108         for (i = 0; i < cmd.length; i++) {
109             if (Pattern.compile(cmd[i]).matcher(sql).matches()) {
110                 break;
111             }
112         }
113         return i;
114     }
115 
116     protected abstract String  [] getVars(int cmd, String   sql);
117     
118 }
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