ea2ddl-dao/src/main/java/jp/sourceforge/ea2ddl/dao/allcommon/s2dao/FetchNarrowingResultSetWrapper.java

   1 package jp.sourceforge.ea2ddl.dao.allcommon.s2dao;\r
   2 \r
   3 import java.sql.ResultSet;\r
   4 import java.sql.Statement;\r
   5 import java.sql.SQLException;\r
   6 \r
   7 import org.seasar.extension.jdbc.impl.ResultSetWrapper;\r
   8 \r
   9 import jp.sourceforge.ea2ddl.dao.allcommon.cbean.FetchNarrowingBean;\r
  10 import jp.sourceforge.ea2ddl.dao.allcommon.s2dao.internal.sqlhandler.InternalBasicHandler.SQLExceptionHandler;\r
  11 \r
  12 /**\r
  13  * The wrapper of fetch narrowing result set.\r
  14  * @author DBFlute(AutoGenerator)\r
  15  */\r
  16 public class FetchNarrowingResultSetWrapper extends ResultSetWrapper {\r
  17 \r
  18     // ===================================================================================\r
  19     //                                                                           Attribute\r
  20     //                                                                           =========\r
  21     /** The real result set. (NotNull) */\r
  22     protected ResultSet _resultSet;\r
  23 \r
  24     /** The bean of fetch narrowing. (NotNull) */\r
  25     protected FetchNarrowingBean _fetchNarrowingBean;\r
  26 \r
  27     /** The counter of fetch. */\r
  28     protected long _fetchCounter;\r
  29 \r
  30     /** the counter of request. */\r
  31     protected long _requestCounter;\r
  32 \r
  33     /** Does it offset by cursor forcedly? */\r
  34     protected boolean _offsetByCursorForcedly;\r
  35 \r
  36     /** Does it limit by cursor forcedly? */\r
  37     protected boolean _limitByCursorForcedly;\r
  38         \r
  39         /** Does it skip to cursor end? */\r
  40         protected boolean _skipToCursorEnd;\r
  41 \r
  42     // ===================================================================================\r
  43     //                                                                         Constructor\r
  44     //                                                                         ===========\r
  45     /**\r
  46      * Constructor.\r
  47      * @param resultSet Original result set. (NotNull)\r
  48      * @param fetchNarrowingBean Fetch-narrowing-bean. (NotNull)\r
  49      * @param offsetByCursorForcedly Offset by cursor forcedly.\r
  50      * @param limitByCursorForcedly Limit by cursor forcedly.\r
  51      */\r
  52     public FetchNarrowingResultSetWrapper(ResultSet resultSet, FetchNarrowingBean fetchNarrowingBean\r
  53                                              , boolean offsetByCursorForcedly, boolean limitByCursorForcedly) {\r
  54         super(resultSet);\r
  55 \r
  56         _resultSet = resultSet;\r
  57         _fetchNarrowingBean = fetchNarrowingBean;\r
  58         _offsetByCursorForcedly = offsetByCursorForcedly;\r
  59         _limitByCursorForcedly = limitByCursorForcedly;\r
  60 \r
  61         skip();\r
  62     }\r
  63 \r
  64     // ===================================================================================\r
  65     //                                                                                Skip\r
  66     //                                                                                ====\r
  67     /**\r
  68      * Skip to start-index.\r
  69      */\r
  70     protected void skip() {\r
  71         if (!isAvailableSkipRecord()) {\r
  72             return;\r
  73         }\r
  74         final int skipStartIndex = getFetchNarrowingSkipStartIndex();\r
  75         if (isScrollableCursor()) {\r
  76             try {\r
  77                 if (0 == skipStartIndex) {\r
  78                     _resultSet.beforeFirst();\r
  79                 } else {\r
  80                     _resultSet.absolute(skipStartIndex);\r
  81                 }\r
  82                 _fetchCounter = _resultSet.getRow();\r
  83             } catch (SQLException e) {\r
  84                 handleSQLException(e, null);\r
  85             }\r
  86         } else {\r
  87             try {\r
  88                 while (true) {\r
  89                                         if (_fetchCounter >= skipStartIndex) {\r
  90                                             break;\r
  91                                         }\r
  92                                         if (!_resultSet.next()) {\r
  93                                             _skipToCursorEnd = true;// [DBFLUTE-243]\r
  94                                             break;\r
  95                                         }\r
  96                     ++_fetchCounter;\r
  97                 }\r
  98             } catch (SQLException e) {\r
  99                 handleSQLException(e, null);\r
 100             }\r
 101         }\r
 102     }\r
 103 \r
 104     protected boolean isAvailableSkipRecord() {\r
 105         if (!isFetchNarrowingEffective()) {\r
 106             return false;\r
 107         }\r
 108         if (isOffsetByCursorForcedly()) {\r
 109             return true;\r
 110         }\r
 111         if (isFetchNarrowingSkipStartIndexEffective()) {\r
 112             return true;\r
 113         }\r
 114         return false;\r
 115     }\r
 116 \r
 117     // ===================================================================================\r
 118     //                                                                                Next\r
 119     //                                                                                ====\r
 120     /**\r
 121      * Next.\r
 122      * @return Does the result set have next record?\r
 123      * @throws SQLException\r
 124      */\r
 125     public boolean next() throws SQLException {\r
 126         final boolean hasNext = super.next();\r
 127         ++_requestCounter;\r
 128         if (!isAvailableLimitLoopCount()) {\r
 129             checkSafetyResult(hasNext);\r
 130             return hasNext;\r
 131         }\r
 132 \r
 133         if (hasNext && _fetchCounter < getFetchNarrowingSkipStartIndex() + getFetchNarrowingLoopCount()) {\r
 134             ++_fetchCounter;\r
 135             checkSafetyResult(true);\r
 136             return true;\r
 137         } else {\r
 138             return false;\r
 139         }\r
 140     }\r
 141 \r
 142     protected boolean isAvailableLimitLoopCount() {\r
 143         if (!isFetchNarrowingEffective()) {\r
 144             return false;\r
 145         }\r
 146         if (isLimitByCursorForcedly()) {\r
 147             return true;\r
 148         }\r
 149         if (isFetchNarrowingLoopCountEffective()) {\r
 150             return true;\r
 151         }\r
 152         return false;\r
 153     }\r
 154 \r
 155     protected void checkSafetyResult(boolean hasNext) {\r
 156         if (hasNext && getSafetyMaxResultSize() > 0 && _requestCounter > (getSafetyMaxResultSize() + 1)) {\r
 157             String msg = "You have already been in Danger Zone!";\r
 158             msg = msg + " Please confirm your query or data of table: safetyMaxResultSize=" + getSafetyMaxResultSize();\r
 159             throw new jp.sourceforge.ea2ddl.dao.allcommon.exception.DangerousResultSizeException(msg, getSafetyMaxResultSize());\r
 160         }\r
 161     }\r
 162 \r
 163     // ===================================================================================\r
 164     //                                                                        Fetch Option\r
 165     //                                                                        ============\r
 166     protected boolean isFetchNarrowingEffective() {\r
 167         return _fetchNarrowingBean.isFetchNarrowingEffective();\r
 168     }\r
 169 \r
 170     protected boolean isFetchNarrowingSkipStartIndexEffective() {\r
 171         return _fetchNarrowingBean.isFetchNarrowingSkipStartIndexEffective();\r
 172     }\r
 173 \r
 174     protected boolean isFetchNarrowingLoopCountEffective() {\r
 175         return _fetchNarrowingBean.isFetchNarrowingLoopCountEffective();\r
 176     }\r
 177 \r
 178     protected int getFetchNarrowingSkipStartIndex() {\r
 179         return _fetchNarrowingBean.getFetchNarrowingSkipStartIndex();\r
 180     }\r
 181 \r
 182     protected int getFetchNarrowingLoopCount() {\r
 183         return _fetchNarrowingBean.getFetchNarrowingLoopCount();\r
 184     }\r
 185 \r
 186     public int getSafetyMaxResultSize() {\r
 187         return _fetchNarrowingBean.getSafetyMaxResultSize();\r
 188     }\r
 189 \r
 190     protected boolean isScrollableCursor() {\r
 191         try {\r
 192             return !(_resultSet.getType() == ResultSet.TYPE_FORWARD_ONLY);\r
 193         } catch (SQLException e) {\r
 194             handleSQLException(e, null);\r
 195             return false;// Unreachable!\r
 196         }\r
 197     }\r
 198 \r
 199     // ===================================================================================\r
 200     //                                                                   Exception Handler\r
 201     //                                                                   =================\r
 202     protected void handleSQLException(SQLException e, Statement statement) {\r
 203         new SQLExceptionHandler().handleSQLException(e, statement);\r
 204     }\r
 205     \r
 206     // ===================================================================================\r
 207     //                                                                            Accessor\r
 208     //                                                                            ========\r
 209     public boolean isOffsetByCursorForcedly() {\r
 210         return _offsetByCursorForcedly;\r
 211     }\r
 212 \r
 213     public boolean isLimitByCursorForcedly() {\r
 214         return _limitByCursorForcedly;\r
 215     }\r
 216         \r
 217         public boolean isSkipToCursorEnd() {\r
 218             return _skipToCursorEnd;\r
 219         }\r
 220 }\r