数据库Util

/** * 根据表名，列名，取下一个数。 * <br> * simple<br> * getNextIndexBySchemaName("mysql","userTable","user_id"); * <br> * @param dbName * @param schemaName * @param fieldName * @return */public static Integer getNextIndexBySchemaName(String dbName,String schemaName, String fieldName) {PreparedStatement stmt = null;PreparedStatement stmt2 = null;ResultSet rs = null;String nextIndex = null;Integer localInteger = null;Connection localConnection = null;try {localConnection = DBConnectionUtil.getInstance().getConnection(dbName);String str2 = "select next_index from field_index where schema_name = ? and field_name=?";stmt = localConnection.prepareStatement(str2);stmt.setString(1, schemaName);stmt.setString(2, fieldName);rs = stmt.executeQuery();if (rs.next()) {nextIndex = rs.getString("next_index");String str3 = "update field_index set next_index = next_index+1 where schema_name =? and field_name=? ";stmt2 = localConnection.prepareStatement(str3);stmt2.setString(1, schemaName);stmt2.setString(2, fieldName);stmt2.executeUpdate();} else {int i = CommonContents.DBUTIL_INIT_INDEX;nextIndex = String.valueOf(i);++i;String str4 = "insert into field_index(schema_name,field_name,next_index) values(?,?,?) ";stmt2 = localConnection.prepareStatement(str4);stmt2.setString(1, schemaName);stmt2.setString(2, fieldName);stmt2.setString(3, String.valueOf(i));stmt2.executeUpdate();}if ((nextIndex != null) && (nextIndex.length() > 0))localInteger = Integer.valueOf(nextIndex);elselocalInteger = new Integer(1);} catch (Exception localException) {log.error("next index error!");} finally {stmtRsClose(stmt2, null);stmtRsClose(stmt, rs);DBConnectionUtil.getInstance().freeConnection(dbName,localConnection);}return localInteger;}public static void main(String[] args) {System.out.println(DBUtil.getNextIndexBySchemaName("mysql", "user", "user_id"));}