让java网站开发从此简单起来[一个项目只用一个Servlet和一个Dao类].doc

参加工作已经有1年了，同时，也整理出了一些快速开发网站的经验，第一次发技术贴，别见怪啊公司接的一些网站也都不大，刚来的时候，是采用ASP.NET开发的，后来用的不顺手（我个人比较倾向于java的），后来便换上java开发，可能有的人认为，用java开发这种中小型网站纯粹是找虐。我却不不认同这个。首先，我觉得用java写这种不大的网站，没必要上SSH这种框架（我自身不太喜欢在配置文件里面狂操作）。更喜欢在服务端采用Servlet，连接池采用的是：proxool。在客户端体验方面，都有很多ajax应用，而ajax采用json数据传输，可直接让URL指向服务端的Servlet，故决定在客户端采用纯HTML的形式,增删改查，一切都通过ajax形式提交到servet处理。考虑到页面多了，需要建立的servlet就会更多，在连续开发了2个网站之后，终于总结了一规律，让整个项目只有一个servlet,也只有一个Dao类。我的思想就是，网站开发，无非就是增删改查，只要服务端提供给我json格式的字符串，然后在客户端由JavaScript完成各种用户体验废话不多说了，马上进入重点-DBAcces.javaview plaincopy to clipboardprint?1. packagecom.util;2. 3. importjava.sql.CallableStatement;4. importjava.sql.Connection;5. importjava.sql.DriverManager;6. importjava.sql.PreparedStatement;7. importjava.sql.ResultSet;8. importjava.sql.ResultSetMetaData;9. importjava.sql.SQLException;10. importjava.util.ArrayList;11. importjava.util.HashMap;12. importjava.util.List;13. importjava.util.Map;14. 15. importcom.ipublic.IDao;16. 17. publicclassDBAccess18. /连接jdbc19. publicstaticConnectiongetConn()20. Connectionconn=null;21. try22. Class.forName(xool.ProxoolDriver);23. conn=DriverManager.getConnection(proxool.default);24. catch(Exceptione1)25. e1.printStackTrace();26. 27. returnconn;28. 29. 30. 31. /*32. *普通SQL查询33. *paramsql34. *paramobj35. *paramdao36. *return37. */38. publicstaticStringgetQueyData(Stringsql,Objectobj,IDaodao)39. Connectionconn=null;40. PreparedStatementps=null;41. ResultSetrs=null;42. StringjsonResult=;43. try44. conn=getConn();45. ps=conn.prepareStatement(sql);46. 47. if(obj!=null)48. 49. for(inti=1;i=obj.length;i+)50. ps.setObject(i,obji-1);51. 52. 53. 54. rs=ps.executeQuery();55. jsonResult=dao.execSelect(rs);56. 57. catch(SQLExceptione)58. e.printStackTrace();59. finally60. closeAll(ps,null,rs,conn);61. 62. returnjsonResult;63. 64. /*65. *返回Table数据66. *paramsql67. *paramobj68. *paramdao69. *return70. */71. publicstaticListMapgetQueyDataOnTable72. (Stringsql,Objectobj)73. ListMaplist=newArrayListMap();74. Connectionconn=null;75. PreparedStatementps=null;76. ResultSetrs=null;77. try78. conn=getConn();79. ps=conn.prepareStatement(sql);80. if(obj!=null)81. 82. for(inti=1;i=obj.length;i+)83. ps.setObject(i,obji-1);84. 85. 86. rs=ps.executeQuery();87. ResultSetMetaDatarsmd=rs.getMetaData();88. while(rs.next()89. Mapmp=newHashMap();90. for(inti=0;irsmd.getColumnCount();i+)91. mp.put(rsmd.getColumnLabel(i+1),92. rs.getString(rsmd.getColumnLabel(i+1);93. 94. list.add(mp);95. 96. 97. catch(SQLExceptione)98. e.printStackTrace();99. finally100. closeAll(ps,null,rs,conn);101. 102. returnlist;103. 104. 105. /*106. *将查询出来的数据以map集合的方式返回107. *paramsql108. *paramobj109. *paramdao110. *return111. */112. publicstaticMapgetQueyDataOnMap(Stringsql,Objectobj)113. Connectionconn=null;114. PreparedStatementps=null;115. ResultSetrs=null;116. Mapmp=newHashMap();117. try118. conn=getConn();119. ps=conn.prepareStatement(sql);120. if(obj!=null)121. 122. for(inti=1;i=obj.length;i+)123. ps.setObject(i,obji-1);124. 125. 126. rs=ps.executeQuery();127. ResultSetMetaDatarsmd=rs.getMetaData();128. if(rs.next()129. for(inti=0;irsmd.getColumnCount();i+)130. mp.put(rsmd.getColumnLabel(i+1),131. rs.getString(rsmd.getColumnLabel(i+1);132. 133. 134. 135. catch(SQLExceptione)136. e.printStackTrace();137. finally138. closeAll(ps,null,rs,conn);139. 140. returnmp;141. 142. 143. /*144. *查询，返回json格式145. *paramsql146. *paramparameters147. *return148. */149. publicstaticStringgetJsonString(Stringsql,Objectparameters)150. Stringrs=getQueyData(sql,parameters,newIDao()151. publicStringexecSelect(ResultSetrs)152. returngetResultToJson(rs);153. 154. );155. returnrs;156. 157. /*158. *更新语句通用方法159. *paramsql160. *paramobj161. *return162. */163. publicstaticintgetUpdateData(Stringsql,Objectobj)164. intresult=0;165. Connectionconn=getConn();166. PreparedStatementps=null;167. try168. ps=conn.prepareStatement(sql);169. if(obj!=null)170. for(inti=1;i=obj.length;i+)171. ps.setObject(i,obji-1);172. 173. 174. result=ps.executeUpdate();175. catch(SQLExceptione)176. e.printStackTrace();177. finally178. closeAll(ps,null,null,conn);179. 180. 181. returnresult;182. 183. publicstaticintgetOneResult(Stringsql,Objectobj)184. Stringresult=getQueyData(sql,obj,newIDao()185. publicStringexecSelect(ResultSetrs)throwsSQLException186. Stringresult=null;187. if(rs.next()188. result=rs.getString(0);189. 190. returnresult;191. 192. 193. );194. returnInteger.parseInt(result);195. 196. /关闭所有打开连接197. privatestaticvoidcloseAll(PreparedStatementp_stmt,198. CallableStatementc_stmt,ResultSetrset,Connectionconn)199. try200. if(p_stmt!=null)201. p_stmt.close();202. 203. if(c_stmt!=null)204. c_stmt.close();205. 206. if(rset!=null)207. rset.close();208. 209. if(!conn.isClosed()|conn!=null)210. conn.close();211. 212. catch(SQLExceptione)213. e.printStackTrace();214. 215. 216. 217. /转换为json数据218. privatestaticStringgetResultToJson(ResultSetrs)219. StringBufferjsonString=newStringBuffer();220. try221. if(rs!=null)222. jsonString.append();223. ResultSetMetaDatarsmd=rs.getMetaData();224. intcolumnsCount=rsmd.getColumnCount();225. StringColumnNames=newStringcolumnsCount;226. for(inti=0;icolumnsCount;i+)227. ColumnNamesi=rsmd.getColumnLabel(i+1);228. 229. while(rs.next()230. jsonString.append();231. for(inti=0;i1)246. jsonString.247. replace(jsonString.length()-1,jsonString.length(),);248. 249. jsonString.append();250. 251. catch(SQLExceptione)252. e.printStackTrace();253. 254. 255. returnjsonString.toString();256. 257. 258. -测试实体类Studen.javaview plaincopy to clipboardprint?1. publicclassStudent2. privateintid;3. privateStringstuName;4. privateintage;5. publicintgetId()6. returnthis.id;7. 8. publicvoidsetId(intid)9. this.id=id10. 11. /以下省略.12. -通用数据访问层类Dao.javaview plaincopy to clipboardprint?1. packagecom.util;2. 3. importjava.io.File;4. importjava.io.IOException;5. importjava.util.List;6. 7. importorg.jdom.Document;8. importorg.jdom.Element;9. importorg.jdom.JDOMException;10. importorg.jdom.input.SAXBuilder;11. 12. publicclassDao13. /*14. *自定义SQL增删改15. *paramnewInstans16. *paramc17. *paramid18. *return19. */20. publicintupdateToAll(Stringparm,Objectobj)21. try22. Stringsql=getSql(parm);23. returnDBAccess.getUpdateData(sql,obj);24. catch(IllegalArgumentExceptione)25. e.printStackTrace();26. catch(SecurityExceptione)27. e.printStackTrace();28. 29. return-1;30. 31. /*32. *查询33. *return34. */35. publicStringget(Stringsearch,Objectobj)36. Stringsql=getSql(search);/获取SQL37. returnDBAccess.getJsonString(sql,obj);38. 39. /*40. *获取SQL41. */42. publicStringgetSql(Stringsearch)43. Stringsql=;44. Documentdoc=null;45. try46. SAXBuilderbuilder=newSAXBuilder();47. doc=builder.build(./webapps/项目名/WEB-INF/dao.xml);48. 49. Elementelt=doc.getRootElement();50. Listlist=elt.getChildren();51. for(Elemente:list)52. if(e.getAttributeValue(name).equals(search)53. sql=e.getAttributeValue(sql);54. 55. 56. catch(JDOMExceptione)57. e.printStackTrace();58. catch(IOExceptione)59. e.printStackTrace();60. 61. returnsql;62. 63. publicStringgetParm(Stringsearch)64. Stringparm=;65. Documentdoc=null;66. try67. SAXBuilderbuilder=newSAXBuilder();68. doc=builder.build(./webapps/项目名/WEB-INF/dao.xml);69. Elementelt=doc.getRootElement();70. Listlist=elt.getChildren();71. for(Elemente:list)72. if(e.getAttributeValue(name).equals(search)73. parm=e.getAttributeValue(parm);74. 75. 76. catch(JDOMExceptione)77. e.printStackTrace();78. catch(IOExceptione)79. e.printStackTrace();80. 81. if(parm.indexOf(,)=0)82. returnparm.split(,);83. else84. returnnewStringparm;85. 86. 87. -Servlet通用类view plaincopy to clipboardprint?1. packagecom.manager.servlet;2. 3. importjava.io.IOException;4. importjava.io.PrintWriter;5. importjava.util.ArrayList;6. importjava.util.List;7. 8. importjavax.servlet.ServletException;9. importjavax.servlet.http.HttpServletRequest;10. importjavax.servlet.http.HttpServletResponse;11. 12. importcom.util.Dao;13. importcom.util.ServletMain;14. 15. publicclassServletManagerextendsHttpServlet16. Daodao=newDao();17. publicvoidservice(HttpServletRequestrequest,18. HttpServletResponseresponse)19. throwsServletException,IOException20. response.setContentType(text/html;charset=UTF-8);21. Stringopt=request.getParameter(opt);22. PrintWriterout=response.getWriter();23. if(opt!=null)24. switch(Integer.parseInt(opt)25. case1:26. update(request,response,out);27. break;28. case2:29. select(request,response,out);30. break;31. 32. 33. 34. /*35. *增删改通用方法36. *paramrequest37. *paramresponse38. *paramout39. *throwsServletException40. *throwsIOException41. */42. publicvoidupdate(HttpServletRequestrequest,43. HttpServletResponseresponse,PrintWriterout)44. throwsServletException,IOException45. Stringparm=request.getParameter(parameter);46. intresult=0;47. try48. if(parm!=null)/如果参数不为空，则使用自定义SQL形式49. Objectobj=getObjs(request,parm);50. result=dao.updateToAll(parm,obj);51. 52. out.println(result);53. catch(ClassNotFoundExceptione)54. e.printStackTrace();55. 56. 57. /*58. *查询通用方法59. *paramrequest60. *paramresponse61. *paramout62. *throwsServletException63. *throwsIOException64. */65. publicvoidselect(HttpServletRequestrequest,66. HttpServletResponseresponse,PrintWriterout)67. throwsServletException,IOException68. Stringparm=request.getParameter(parameter);69. if(parm!=null)70. Objectobj=getObjs(request,parm);71. out.println(dao.get(parm,obj);72. 73. 74. 75. /*76. *获取参数列表77. *paramrequest78. *paramparm79. *return80. */81. privateObjectgetObjs(HttpServletRequestrequest,Stringparm)82. Listlist=newAr