Java tutorial
/** * GNU GENERAL PUBLIC LICENSE * Version 2, June 1991 * <p/> * Copyright (C) 1989, 1991 Free Software Foundation, Inc., <http://fsf.org/> * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * Everyone is permitted to copy and distribute verbatim copies * of this license document, but changing it is not allowed. * <p/> * Preamble * <p/> * The licenses for most software are designed to take away your * freedom to share and change it. By contrast, the GNU General Public * License is intended to guarantee your freedom to share and change free * software--to make sure the software is free for all its users. This * General Public License applies to most of the Free Software * Foundation's software and to any other program whose authors commit to * using it. (Some other Free Software Foundation software is covered by * the GNU Lesser General Public License instead.) You can apply it to * your programs, too. * <p/> * When we speak of free software, we are referring to freedom, not * price. Our General Public Licenses are designed to make sure that you * have the freedom to distribute copies of free software (and charge for * this service if you wish), that you receive source code or can get it * if you want it, that you can change the software or use pieces of it * in new free programs; and that you know you can do these things. * <p/> * To protect your rights, we need to make restrictions that forbid * anyone to deny you these rights or to ask you to surrender the rights. * These restrictions translate to certain responsibilities for you if you * distribute copies of the software, or if you modify it. * <p/> * For example, if you distribute copies of such a program, whether * gratis or for a fee, you must give the recipients all the rights that * you have. You must make sure that they, too, receive or can get the * source code. And you must show them these terms so they know their * rights. * <p/> * We protect your rights with two steps: (1) copyright the software, and * (2) offer you this license which gives you legal permission to copy, * distribute and/or modify the software. * <p/> * Also, for each author's protection and ours, we want to make certain * that everyone understands that there is no warranty for this free * software. If the software is modified by someone else and passed on, we * want its recipients to know that what they have is not the original, so * that any problems introduced by others will not reflect on the original * authors' reputations. * <p/> * Finally, any free program is threatened constantly by software * patents. We wish to avoid the danger that redistributors of a free * program will individually obtain patent licenses, in effect making the * program proprietary. To prevent this, we have made it clear that any * patent must be licensed for everyone's free use or not licensed at all. * <p/> * The precise terms and conditions for copying, distribution and * modification follow. * <p/> * GNU GENERAL PUBLIC LICENSE * TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION * <p/> * 0. This License applies to any program or other work which contains * a notice placed by the copyright holder saying it may be distributed * under the terms of this General Public License. The "Program", below, * refers to any such program or work, and a "work based on the Program" * means either the Program or any derivative work under copyright law: * that is to say, a work containing the Program or a portion of it, * either verbatim or with modifications and/or translated into another * language. (Hereinafter, translation is included without limitation in * the term "modification".) Each licensee is addressed as "you". * <p/> * Activities other than copying, distribution and modification are not * covered by this License; they are outside its scope. The act of * running the Program is not restricted, and the output from the Program * is covered only if its contents constitute a work based on the * Program (independent of having been made by running the Program). * Whether that is true depends on what the Program does. * <p/> * 1. You may copy and distribute verbatim copies of the Program's * source code as you receive it, in any medium, provided that you * conspicuously and appropriately publish on each copy an appropriate * copyright notice and disclaimer of warranty; keep intact all the * notices that refer to this License and to the absence of any warranty; * and give any other recipients of the Program a copy of this License * along with the Program. * <p/> * You may charge a fee for the physical act of transferring a copy, and * you may at your option offer warranty protection in exchange for a fee. * <p/> * 2. You may modify your copy or copies of the Program or any portion * of it, thus forming a work based on the Program, and copy and * distribute such modifications or work under the terms of Section 1 * above, provided that you also meet all of these conditions: * <p/> * a) You must cause the modified files to carry prominent notices * stating that you changed the files and the date of any change. * <p/> * b) You must cause any work that you distribute or publish, that in * whole or in part contains or is derived from the Program or any * part thereof, to be licensed as a whole at no charge to all third * parties under the terms of this License. * <p/> * c) If the modified program normally reads commands interactively * when run, you must cause it, when started running for such * interactive use in the most ordinary way, to print or display an * announcement including an appropriate copyright notice and a * notice that there is no warranty (or else, saying that you provide * a warranty) and that users may redistribute the program under * these conditions, and telling the user how to view a copy of this * License. (Exception: if the Program itself is interactive but * does not normally print such an announcement, your work based on * the Program is not required to print an announcement.) * <p/> * These requirements apply to the modified work as a whole. If * identifiable sections of that work are not derived from the Program, * and can be reasonably considered independent and separate works in * themselves, then this License, and its terms, do not apply to those * sections when you distribute them as separate works. But when you * distribute the same sections as part of a whole which is a work based * on the Program, the distribution of the whole must be on the terms of * this License, whose permissions for other licensees extend to the * entire whole, and thus to each and every part regardless of who wrote it. * <p/> * Thus, it is not the intent of this section to claim rights or contest * your rights to work written entirely by you; rather, the intent is to * exercise the right to control the distribution of derivative or * collective works based on the Program. * <p/> * In addition, mere aggregation of another work not based on the Program * with the Program (or with a work based on the Program) on a volume of * a storage or distribution medium does not bring the other work under * the scope of this License. * <p/> * 3. You may copy and distribute the Program (or a work based on it, * under Section 2) in object code or executable form under the terms of * Sections 1 and 2 above provided that you also do one of the following: * <p/> * a) Accompany it with the complete corresponding machine-readable * source code, which must be distributed under the terms of Sections * 1 and 2 above on a medium customarily used for software interchange; or, * <p/> * b) Accompany it with a written offer, valid for at least three * years, to give any third party, for a charge no more than your * cost of physically performing source distribution, a complete * machine-readable copy of the corresponding source code, to be * distributed under the terms of Sections 1 and 2 above on a medium * customarily used for software interchange; or, * <p/> * c) Accompany it with the information you received as to the offer * to distribute corresponding source code. (This alternative is * allowed only for noncommercial distribution and only if you * received the program in object code or executable form with such * an offer, in accord with Subsection b above.) * <p/> * The source code for a work means the preferred form of the work for * making modifications to it. For an executable work, complete source * code means all the source code for all modules it contains, plus any * associated interface definition files, plus the scripts used to * control compilation and installation of the executable. However, as a * special exception, the source code distributed need not include * anything that is normally distributed (in either source or binary * form) with the major components (compiler, kernel, and so on) of the * operating system on which the executable runs, unless that component * itself accompanies the executable. * <p/> * If distribution of executable or object code is made by offering * access to copy from a designated place, then offering equivalent * access to copy the source code from the same place counts as * distribution of the source code, even though third parties are not * compelled to copy the source along with the object code. * <p/> * 4. You may not copy, modify, sublicense, or distribute the Program * except as expressly provided under this License. Any attempt * otherwise to copy, modify, sublicense or distribute the Program is * void, and will automatically terminate your rights under this License. * However, parties who have received copies, or rights, from you under * this License will not have their licenses terminated so long as such * parties remain in full compliance. * <p/> * 5. You are not required to accept this License, since you have not * signed it. However, nothing else grants you permission to modify or * distribute the Program or its derivative works. These actions are * prohibited by law if you do not accept this License. Therefore, by * modifying or distributing the Program (or any work based on the * Program), you indicate your acceptance of this License to do so, and * all its terms and conditions for copying, distributing or modifying * the Program or works based on it. * <p/> * 6. Each time you redistribute the Program (or any work based on the * Program), the recipient automatically receives a license from the * original licensor to copy, distribute or modify the Program subject to * these terms and conditions. You may not impose any further * restrictions on the recipients' exercise of the rights granted herein. * You are not responsible for enforcing compliance by third parties to * this License. * <p/> * 7. If, as a consequence of a court judgment or allegation of patent * infringement or for any other reason (not limited to patent issues), * conditions are imposed on you (whether by court order, agreement or * otherwise) that contradict the conditions of this License, they do not * excuse you from the conditions of this License. If you cannot * distribute so as to satisfy simultaneously your obligations under this * License and any other pertinent obligations, then as a consequence you * may not distribute the Program at all. For example, if a patent * license would not permit royalty-free redistribution of the Program by * all those who receive copies directly or indirectly through you, then * the only way you could satisfy both it and this License would be to * refrain entirely from distribution of the Program. * <p/> * If any portion of this section is held invalid or unenforceable under * any particular circumstance, the balance of the section is intended to * apply and the section as a whole is intended to apply in other * circumstances. * <p/> * It is not the purpose of this section to induce you to infringe any * patents or other property right claims or to contest validity of any * such claims; this section has the sole purpose of protecting the * integrity of the free software distribution system, which is * implemented by public license practices. Many people have made * generous contributions to the wide range of software distributed * through that system in reliance on consistent application of that * system; it is up to the author/donor to decide if he or she is willing * to distribute software through any other system and a licensee cannot * impose that choice. * <p/> * This section is intended to make thoroughly clear what is believed to * be a consequence of the rest of this License. * <p/> * 8. If the distribution and/or use of the Program is restricted in * certain countries either by patents or by copyrighted interfaces, the * original copyright holder who places the Program under this License * may add an explicit geographical distribution limitation excluding * those countries, so that distribution is permitted only in or among * countries not thus excluded. In such case, this License incorporates * the limitation as if written in the body of this License. * <p/> * 9. The Free Software Foundation may publish revised and/or new versions * of the General Public License from time to time. Such new versions will * be similar in spirit to the present version, but may differ in detail to * address new problems or concerns. * <p/> * Each version is given a distinguishing version number. If the Program * specifies a version number of this License which applies to it and "any * later version", you have the option of following the terms and conditions * either of that version or of any later version published by the Free * Software Foundation. If the Program does not specify a version number of * this License, you may choose any version ever published by the Free Software * Foundation. * <p/> * 10. If you wish to incorporate parts of the Program into other free * programs whose distribution conditions are different, write to the author * to ask for permission. For software which is copyrighted by the Free * Software Foundation, write to the Free Software Foundation; we sometimes * make exceptions for this. Our decision will be guided by the two goals * of preserving the free status of all derivatives of our free software and * of promoting the sharing and reuse of software generally. * <p/> * NO WARRANTY * <p/> * 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY * FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN * OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES * PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED * OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS * TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE * PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, * REPAIR OR CORRECTION. * <p/> * 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING * WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR * REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, * INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING * OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED * TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY * YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER * PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE * POSSIBILITY OF SUCH DAMAGES. * <p/> * END OF TERMS AND CONDITIONS * <p/> * How to Apply These Terms to Your New Programs * <p/> * If you develop a new program, and you want it to be of the greatest * possible use to the public, the best way to achieve this is to make it * free software which everyone can redistribute and change under these terms. * <p/> * To do so, attach the following notices to the program. It is safest * to attach them to the start of each source file to most effectively * convey the exclusion of warranty; and each file should have at least * the "copyright" line and a pointer to where the full notice is found. * <p/> * {description} * Copyright (C) {year} {fullname} * <p/> * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * <p/> * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * <p/> * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * <p/> * Also add information on how to contact you by electronic and paper mail. * <p/> * If the program is interactive, make it output a short notice like this * when it starts in an interactive mode: * <p/> * Gnomovision version 69, Copyright (C) year name of author * Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. * This is free software, and you are welcome to redistribute it * under certain conditions; type `show c' for details. * <p/> * The hypothetical commands `show w' and `show c' should show the appropriate * parts of the General Public License. Of course, the commands you use may * be called something other than `show w' and `show c'; they could even be * mouse-clicks or menu items--whatever suits your program. * <p/> * You should also get your employer (if you work as a programmer) or your * school, if any, to sign a "copyright disclaimer" for the program, if * necessary. Here is a sample; alter the names: * <p/> * Yoyodyne, Inc., hereby disclaims all copyright interest in the program * `Gnomovision' (which makes passes at compilers) written by James Hacker. * <p/> * {signature of Ty Coon}, 1 April 1989 * Ty Coon, President of Vice * <p/> * This General Public License does not permit incorporating your program into * proprietary programs. If your program is a subroutine library, you may * consider it more useful to permit linking proprietary applications with the * library. If this is what you want to do, use the GNU Lesser General * Public License instead of this License. */ package org.fao.faostat.api.core.jdbc; import com.google.gson.Gson; import com.google.gson.JsonObject; import com.microsoft.sqlserver.jdbc.SQLServerDriver; import org.apache.commons.lang3.StringEscapeUtils; import org.apache.log4j.Logger; import org.fao.faostat.api.core.beans.DatasourceBean; import org.fao.faostat.api.core.constants.DRIVER; import org.json.simple.JSONObject; import java.io.IOException; import java.sql.*; import java.util.*; import java.util.Date; /** * @author <a href="mailto:guido.barbaglia@gmail.com">Guido Barbaglia</a> */ public class JDBCIterable implements Iterator<List<String>> { private static final Logger LOGGER = Logger.getLogger(JDBCIterable.class); private Connection connection; private Statement statement; private ResultSet resultSet; private boolean hasNext; private int columns; public void query(DatasourceBean db, String sql) throws Exception { DRIVER d = DRIVER.valueOf(db.getDriver().toUpperCase()); switch (d) { case SQLSERVER2000: try { querySQLServer(db, sql); } catch (Exception e) { e.printStackTrace(); throw new Exception(e.getMessage()); } break; } } public void querySQLServer(DatasourceBean db, String sql) throws Exception { try { //LOGGER.info("db.getUrl(): " + db.getUrl()); /* Open connections. */ SQLServerDriver.class.newInstance(); this.setConnection(DriverManager.getConnection(db.getUrl(), db.getUsername(), db.getPassword())); this.setStatement(this.getConnection().createStatement()); this.getStatement().executeQuery(sql); this.setResultSet(this.getStatement().getResultSet()); this.setColumns(this.getResultSet().getMetaData().getColumnCount()); } catch (Exception e) { LOGGER.error(e.getMessage()); throw new Exception(e.getMessage()); } } @Override public boolean hasNext() { return this.isHasNext(); } public List<String> getColumnNames() { List<String> l = new ArrayList<String>(); try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { l.add(this.getResultSet().getMetaData().getColumnLabel(i)); } } catch (NullPointerException ignored) { } catch (SQLException ignored) { } return l; } public List<String> getColumnTypes() { List<String> l = new ArrayList<String>(); try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { l.add(this.getResultSet().getMetaData().getColumnClassName(i)); } } catch (NullPointerException ignored) { } catch (SQLException ignored) { } return l; } @Override public List<String> next() { List<String> l = null; if (this.isHasNext()) { l = new ArrayList<String>(); try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { try { l.add(this.getResultSet().getString(i).trim()); } catch (NullPointerException ignored) { } } this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } } if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } return l; } public String nextJSON() { /*JSONObject obj = new JSONObject(); if (this.isHasNext()) { try { for (int i = 1 ; i <= this.getResultSet().getMetaData().getColumnCount() ; i++) { try { obj.put(this.getResultSet().getMetaData().getColumnLabel(i).trim(), this.getResultSet().getObject(i)); } catch (NullPointerException ignored) { obj.put(this.getResultSet().getMetaData().getColumnLabel(i).trim(), null); } } this.setHasNext(this.getResultSet().next()); } catch(SQLException ignored) { } } if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } return obj.toString();*/ Gson gson = new Gson(); return gson.toJson(nextMap()); } public Map<String, Object> nextMap() { Map<String, Object> out = new LinkedHashMap<String, Object>(); String value; String columnType; if (this.isHasNext()) { try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { try { columnType = this.getResultSet().getMetaData().getColumnClassName(i); value = this.getResultSet().getString(i).trim(); if (columnType.endsWith("Double")) { out.put(this.getResultSet().getMetaData().getColumnLabel(i), new Double(value)); } else if (columnType.endsWith("Integer")) { out.put(this.getResultSet().getMetaData().getColumnLabel(i), new Integer(value)); } else if (columnType.endsWith("Long")) { out.put(this.getResultSet().getMetaData().getColumnLabel(i), new Long(value)); } else if (columnType.endsWith("Date")) { out.put(this.getResultSet().getMetaData().getColumnLabel(i), new Date(value)); } else { out.put(this.getResultSet().getMetaData().getColumnLabel(i), value.toString()); } } catch (NullPointerException ignored) { if (i > 0) { out.put(this.getResultSet().getMetaData().getColumnLabel(i), null); } } } this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } } if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } return out; } public String nextCSV() { StringBuilder sb = new StringBuilder(); String columnType; String value; if (this.isHasNext()) { try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { try { columnType = this.getResultSet().getMetaData().getColumnClassName(i); value = this.getResultSet().getString(i).trim(); if (columnType.endsWith("Double")) { sb.append(Double.parseDouble(value)); } else if (columnType.endsWith("Integer")) { sb.append(Integer.parseInt(value)); } else if (columnType.endsWith("Long")) { sb.append(Long.parseLong(value)); } else if (columnType.endsWith("Date")) { sb.append(StringEscapeUtils.escapeCsv(value)); //sb.append("\"").append(new Date(value).toString()).append("\""); } else { // TODO: check if there are "" in the string sb.append(StringEscapeUtils.escapeCsv(value)); } if (i <= this.getResultSet().getMetaData().getColumnCount() - 1) { sb.append(","); } else { sb.append("\n"); } } catch (NullPointerException ignored) { if (i > 0) { sb.append(""); } if (i <= this.getResultSet().getMetaData().getColumnCount() - 1) { sb.append(","); } else { sb.append("\n"); } } } this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } } if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } else { //sb.append("\n"); } return sb.toString(); } public String[] nextCSV2() { String[] sb = new String[0]; try { sb = new String[this.getResultSet().getMetaData().getColumnCount()]; String columnType; String value; if (this.isHasNext()) { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { try { columnType = this.getResultSet().getMetaData().getColumnClassName(i); value = this.getResultSet().getString(i).trim(); if (columnType.endsWith("Double")) { sb[i - 1] = String.valueOf(Double.parseDouble(value)); } else if (columnType.endsWith("Integer")) { sb[i - 1] = String.valueOf(Integer.parseInt(value)); } else if (columnType.endsWith("Long")) { sb[i - 1] = String.valueOf(Long.parseLong(value)); } else if (columnType.endsWith("Date")) { sb[i - 1] = new Date(value).toString(); } else { sb[i - 1] = String.valueOf(value); } } catch (NullPointerException ignored) { if (i > 0) { sb[i - 1] = ""; } } } } this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } else { //sb.append("\n"); } return sb; } /* @Deprecated */ public String nextArray() { String s = "["; String columnType; String value; if (this.isHasNext()) { try { for (int i = 1; i <= this.getResultSet().getMetaData().getColumnCount(); i++) { try { columnType = this.getResultSet().getMetaData().getColumnClassName(i); value = this.getResultSet().getString(i).trim(); if (columnType.endsWith("Double")) { s += Double.parseDouble(value); } else if (columnType.endsWith("Integer")) { s += Integer.parseInt(value); } else if (columnType.endsWith("Long")) { s += Long.parseLong(value); } else if (columnType.endsWith("Date")) { s += new Date(value).toString(); } else { s += "\"" + value + "\""; } if (i <= this.getResultSet().getMetaData().getColumnCount() - 1) s += ","; } catch (NullPointerException ignored) { if (i > 0) s += null; if (i <= this.getResultSet().getMetaData().getColumnCount() - 1) s += ","; } } this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } } s += "]"; if (!this.isHasNext()) { try { this.getResultSet().close(); this.getStatement().close(); this.getConnection().close(); } catch (SQLException ignored) { } } return s; } @Override public void remove() { } public ResultSet getResultSet() { return this.resultSet; } public void setResultSet(ResultSet resultSet) { this.resultSet = resultSet; try { this.setHasNext(this.getResultSet().next()); } catch (SQLException ignored) { } } public Connection getConnection() { return connection; } public Statement getStatement() { return statement; } public void setConnection(Connection connection) { this.connection = connection; } public void setStatement(Statement statement) { this.statement = statement; } public boolean isHasNext() { return hasNext; } public void setHasNext(boolean hasNext) { this.hasNext = hasNext; } public void setColumns(int columns) { this.columns = columns; } }