因为帮人做个网站，不想再用vs，改用java。但做小应用没必要用servlet这些重口味的。因此试试jsp，把过程写下来备忘：
一、JSP语法：
1、import包：<%@ page contentType="text/html; charset=gb2312" language="java" import="java.util.*,com.jspsmart.upload.*" errorPage="" %>
2、包含文件：<%@ include file="/conn.jsp" %>
3、常用对象：
- String yid = request.getParameter("yid").toString();//注意getParameter和getAttribute的区别。
- response.sendRedirect("abc.jsp");//注意服务器端跳转和客户端跳转的区别。
- String name = (String)session.getAttribute("name");
二、分页代码：
分页其实比较简单，取数时有两种方法，一个是全部取出来，然后根据页数展示相应数据；另一种是只取特定位置数据，需要数据库支持（此处未用）。代码分成两部分，一部分是数据展示，一部分是翻页展示。
1 <table width= " 98% " border= " 0 " align= " center " cellpadding= " 0 " cellspacing= " 0 "> 2 <tr> 3 <td height= " 25 "><b><font color= " #FF0000 ">信息列表</font></b></td> 4 </tr> 5 <tr> 6 <td><table width= " 100% " border= " 0 " cellspacing= " 0 " cellpadding= " 0 " bgcolor= " #799AE1 "> 7 <tr> 8 <form action= " newsgl.jsp " method= " post " name= " toGetBWList " id= " Form1 "> 9 <td height= " 30 " align=left> 搜索： 10 <input name= " keyword " type=text value= "" class= " button1 "> 11 <input type= " submit " name= " Submit " value= " 搜 索 " class= " button2 "> 12 </td> 13 <td align=right> 14 <div align= " center "> 15 <input type= " button " name= " add " value= " 新 增 " class= " button2 " οnclick= " javascript:window.open('newsmodify.jsp'); "> 16 <input name=reloadPage type=button value= " 刷 新 " id= " reloadPage " onClick= " javascript:window.location.reload(); " class= " button2 "> 17 </div></td> 18 </form> 19 </tr> 20 </table> 21 <br> 22 <table width= " 100% " border= " 1 " cellspacing= " 0 " cellpadding= " 0 " bordercolordark= " #FFFFFF " bordercolorlight= " #CCCCCC "> 23 <tr bgcolor= " #799AE1 "> 24 <td width= " 6% "><div align= ' center '><font color= " #FFFFFF ">选定</font></div></td> 25 <td height= " 20 " bgcolor= " #799AE1 "><div align= " center "><font color= " #FFFFFF ">标题</font></div></td> 26 <td width= " 22% " height= " 20 "><div align= " center "><font color= " #FFFFFF ">作者</font></div></td> 27 28 <td width= " 7% "><div align= " center "><font color= " #FFFFFF ">修改</font></div></td> 29 </tr> 30 <form name= " delnews " action= " newsgl.jsp " method=post> 31 <input name= " action " type= " hidden " value= "" id= " action "> 32 <% 33 int intPageSize; // 一页显示的记录数 34 int intRowCount= 0; // 记录总数 35 int intPageCount= 1; // 总页数 36 int intPage; // 待显示页码 37 String strPage; 38 int i; 39 // 设置一页显示的记录数 40 intPageSize = 20; 41 // 取得待显示页码 42 strPage = request.getParameter( " page "); 43 if(strPage== null){ // 表明在QueryString中没有page这一个参数，此时显示第一页数据 44 intPage = 1; 45 } 46 else{ // 将字符串转换成整型 47 intPage = java.lang.Integer.parseInt(strPage); 48 if(intPage< 1) intPage = 1; 49 } 50 String keyword=request.getParameter( " keyword "); 51 if(keyword== null)keyword= " * "; 52 else if(keyword.equals( ""))keyword= " * "; 53 else keyword = " * "+keyword+ " * "; 54 String action = request.getParameter( " action "); 55 if((action!= null)&&(action.equals( " del "))){ // delete items 56 try{ 57 Connection con1=DriverManager.getConnection(dburl) ; 58 for( int j= 0;j<request.getParameterValues( " NewsID ").length;j++){ 59 PreparedStatement stmt1 = con1.prepareStatement( " delete from news where nid=? "); 60 stmt1.setInt( 1,Integer.parseInt(request.getParameterValues( " NewsID ")[j])); 61 stmt1.executeUpdate(); 62 stmt1.close(); 63 } 64 con1.close(); 65 } catch(Exception ex){ 66 ex.printStackTrace(); 67 } 68 } 69 try{ 70 String title= ""; 71 String author= ""; 72 String content = ""; 73 int nid = 0; 74 Connection con=DriverManager.getConnection(dburl) ; 75 PreparedStatement stmt = con.prepareStatement( " select * from news ",java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY); 76 ResultSet rst=stmt.executeQuery(); 77 78 // 获取记录总数 79 rst.last(); // ??光标在最后一行 80 intRowCount = rst.getRow(); // 获得当前行号 81 // 记算总页数 82 intPageCount = (intRowCount+intPageSize- 1) / intPageSize; 83 // 调整待显示的页码 84 if(intPage>intPageCount) intPage = intPageCount; 85 86 if(intPageCount> 0){ 87 // 将记录指针定位到待显示页的第一条记录上 88 rst.absolute((intPage- 1) * intPageSize + 1); 89 90 int c = 0; 91 while(c<intPageSize && !rst.isAfterLast()) 92 { 93 c++; 94 title=rst.getString( " title "); 95 author=rst.getString( " author "); 96 content=rst.getString( " content "); 97 nid=rst.getInt( " nid "); 98 %> 99 <tr> 100 <td width= " 6% "><div align= " center "><input type= " checkbox " name= " NewsID " value= " <%=nid%> "></div></td> 101 <td height= " 43% " align= " center " style= " word-break:break-all; "><a href= ' newsmodify.jsp?nid=<%=nid %> ' class= ' tt4 ' target= ' _blank '><%=title %></a></td> 102 <td width= " 43% " height= " 22 "><div align= " center "><a href= ' newsmodify.jsp?nid=<%=nid %> ' class= ' tt4 ' target= ' _blank '><%=author %></a></div></td> 103 <td width= " 8% "><div align= ' center '><a href= " newsmodify.jsp?nid=<%=nid %> " class= " tt2 ">修改</a></div></td> 104 </tr> 105 <% 106 rst.next(); 107 } 108 } 109 rst.close(); 110 stmt.close(); 111 con.close(); 112 } catch(Exception ex){ 113 ex.printStackTrace(); 114 } 115 %> 116 </form> 117 </table> 118 <table width= " 100% " border= " 0 " cellpadding= " 0 " cellspacing= " 0 "> 119 <form name= " pageform " method= " post " action= " newsgl.jsp "> 120 <tr> 121 <td width= " 6% " height= " 25 "> 122 <div align= " center "> 123 <input type= ' checkbox ' name= ' selectCheck ' id=selectCheck2 οnclick= " javascript:SelectCheckBox(); "> 124 </div></td> 125 <td width= " 33% ">全部选中 126 <input name= " delbtn " value= " 删除 " type= " button " class= " button2 " οnclick= " javascript:cdel(); "> 127 128 </td> 129 <td> 130 <div align= " right "> 131 共<%=intRowCount %>条信息 当前为：<font color= " #FF0000 "><%=intPage %></font>/<%=intPageCount %>页 132 <% if(intPage> 1){%><a href= " newsgl.jsp?page=<%=intPage-1%>&keyword=<%=keyword%> ">上一页</a><%}%> 133 <% if(intPage<intPageCount){%><a href= " newsgl.jsp?page=<%=intPage+1%> ">下一页</a><%}%> 134 跳到第 <input type=text size= 3 name= " page " value= "" class= " button1 "> 页 135 <input type= " hidden " name= " keyword " value= " <%=keyword%> "> 136 <input name= " imageField " type= " image " src= " go.gif " border= " 0 " align= " absmiddle "> 137 </div></td> 138 </tr> 139 </form> 140 </table></td> 141 </tr> 142 </table>
其中33-98行是分页数据产生代码；99-115行是循环展示的HTML代码；129-137行是翻页代码。
三、访问数据库：
windows下访问access数据库有2个方法：jdbc-odbc方式和jdbc方式。windows下的jdbc-odbc方式很简单，直接用getConnection即可（至少在我的机器上无需调用Class.forName("xxdriver").newInstance()），linux下应该是没有jdbc-odbc方式吧。jdbc方式需要Access_JDBC30.jar。
1、access的jdbc-odbc方式：
String dburl= " jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=e:/Projects/workspace.win/qyjskf/WebContent/WEB-INF/qysjkf.mdb "; Connection con=DriverManager.getConnection(dburl) ; PreparedStatement stmt = con.prepareStatement( " select * from magazines where qkll=? and journals=? "); stmt.setInt( 1,yid); stmt.setInt( 2,jid); ResultSet rst=stmt.executeQuery(); int c = 0; while(rst.next()){ // do something } rst.close(); stmt.close(); con.close();
2、常用的jdbc方式，使用DriverManager.getConnection()获取连接：
// Access 数据库 jdbc驱动 try{ Class.forName( " com.hxtt.sql.access.AccessDriver ").newInstance(); } catch(Exception ex){ out.println( " [错误] 加载数据库驱动出错 "); } String dburl= " jdbc:Access:///c:/test.mdb "; // SQL Server数据库 jtds驱动 try{ Class.forName( " net.sourceforge.jtds.jdbc.Driver ").newInstance(); } catch(Exception ex){ out.println( " [错误] 加载数据库驱动出错 "); } String dburl = " jdbc:jtds:sqlserver://127.0.0.1:7788/test;user=dbuser;password=dbpassword "; // SQL Server数据库 Microsoft jdbc驱动 try{ Class.forName( " com.microsoft.jdbc.sqlserver.SQLServerDriver ").newInstance(); } catch(Exception ex){ out.println( " [错误] 加载数据库驱动出错 "); } String dburl = " jdbc:microsoft:sqlserver://127.0.0.1:7788; DatabaseName=test;user=dbuser;password=dbpassword ";
// Oracle数据库 Oracle jdbc驱动 try{ Class.forName( " oracle.jdbc.OracleDriver ").newInstance(); } catch(Exception ex){ out.println( " [错误] 加载数据库驱动出错 "); } String dburl = " jdbc:oracle:thin:@host:1521:testdb "; // jdbc-odbc桥模式访问Access // String dburl="jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=c:/test.mdb";
四、OLE数据读写：
OLE数据的读写很简单：
FileInputStream inf = null; inf = new FileInputStream(uploadpath+ " / "+file.getFileName()); int length = inf.available(); stmt = con.prepareStatement( " update magazines set title=?,abstracts=?,author=?,year=?,journals=?,filename=?,filetype=?,topic=? where mid=? "); stmt.setBinaryStream( 8,inf,length); int rst=stmt.executeUpdate(); inf.close();
读取就用getBinaryStream方法。详情可参考。
五、上传下载文件：
上传文件方法很多，大多用到组件。这里用的是jspsmart，功能很简单，但是够用了。可参考和。
上传文件代码：
1 SmartUpload su = new SmartUpload(); // 必须最先调用 2 su.initialize(pageContext); // 必须先初始化 3 // 设定允许上传的文件（通过扩展名限制）,仅允许doc,txt文件。 4 su.setAllowedFilesList( " doc,txt,pdf "); 5 // jsp,htm,html扩展名的文件和没有扩展名的文件。 6 su.setDeniedFilesList( " exe,bat,jsp,htm,html "); 7 // 上传文件 8 su.upload(); 9 // 将上传文件全部保存到指定目录 10 int count = su.save(uploadpath); // ,SmartUpload.SAVE_VIRTUAL); 11 com.jspsmart.upload.Request mrequest = su.getRequest(); 12 // 利用Request对象获取参数之值 13 String act = mrequest.getParameter( " act ")== null? "":mrequest.getParameter( " act "); 14 String title = mrequest.getParameter( " d_title ")== null? "":mrequest.getParameter( " d_title "); 15 String abstracts = mrequest.getParameter( " d_abstracts ")== null? "":mrequest.getParameter( " d_abstracts "); 16 String author = mrequest.getParameter( " d_author ")== null? "":mrequest.getParameter( " d_author "); 17 int year = 2012; 18 try{ 19 year = Integer.parseInt(mrequest.getParameter( " d_year ")); 20 } catch(Exception ex){ 21 year = 2012; 22 } 23 int journals = 1; 24 try{ 25 journals = Integer.parseInt(mrequest.getParameter( " d_journals ")); 26 } catch(Exception ex){ 27 journals = 1; 28 } 29 int mid = 1; 30 try{ 31 mid = Integer.parseInt(mrequest.getParameter( " mid ")); 32 } catch(Exception ex){ 33 mid = 0; 34 } 35 36 // 逐一提取上传文件信息，同时可保存文件。 37 if(su.getFiles().getCount() > 0) 38 { 39 com.jspsmart.upload.File file = su.getFiles().getFile( 0); 40 try{ 41 Connection con=DriverManager.getConnection(dburl) ; 42 PreparedStatement stmt; 43 int rst = 0; 44 FileInputStream inf = null; 45 inf = new FileInputStream(uploadpath+ " / "+file.getFileName()); 46 int length = inf.available(); 47 if(mid> 0){ // update old news 48 stmt = con.prepareStatement( " update magazines set title=?,abstracts=?,author=?,year=?,journals=?,filename=?,filetype=?,topic=? where mid=? "); 49 stmt.setString( 1,title); 50 stmt.setString( 2,abstracts); 51 stmt.setString( 3,author); 52 stmt.setInt( 4,year); 53 stmt.setInt( 5,journals); 54 stmt.setString( 6,file.getFileName()); 55 stmt.setString( 7,file.getFileExt()); 56 stmt.setBinaryStream( 8,inf,length); 57 stmt.setInt( 9,mid); 58 // out.println("<script>alert('do update')</script>"); 59 } else{ // add new news 60 stmt = con.prepareStatement( " insert into magazines(title,abstracts,author,year,journals,filename,filetype,topic) values(?,?,?,?,?,?,?,?) "); 61 stmt.setString( 1,title); 62 stmt.setString( 2,abstracts); 63 stmt.setString( 3,author); 64 stmt.setInt( 4,year); 65 stmt.setInt( 5,journals); 66 stmt.setString( 6,file.getFileName()); 67 stmt.setString( 7,file.getFileExt()); 68 stmt.setBinaryStream( 8,inf,length); 69 // out.println("<script>alert('do insert')</script>"); 70 } 71 rst=stmt.executeUpdate(); 72 inf.close(); 73 java.io.File myDelFile= new java.io.File(uploadpath+ " / "+file.getFileName()); 74 if(myDelFile.exists()) 75 { 76 myDelFile.delete(); 77 } 78 79 if(rst> 0){ 80 out.println( " <script>alert(\"修改成功\");</script> "); 81 } else{ 82 out.println( " <script>alert(\"修改失败\");</script> "); 83 } 84 stmt.close(); 85 con.close(); 86 // response.sendRedirect("qkgl.jsp"); 87 } catch(Exception ex){ 88 ex.printStackTrace(); 89 } 90 }
下载文件代码：
1 int mid = 0; 2 String title= ""; 3 try{ 4 mid = Integer.parseInt(request.getParameter( " mid ")); 5 } catch(Exception ex){ 6 mid = 0; 7 } 8 if(mid== 0){ 9 out.println( " <script>alert('无此文档');</script> "); 10 } else{ 11 try{ 12 Connection con=DriverManager.getConnection(dburl) ; 13 PreparedStatement stmt = con.prepareStatement( " select * from magazines where mid=? "); 14 stmt.setInt( 1,mid); 15 ResultSet rst = stmt.executeQuery(); 16 if(rst.next()){ 17 String fn = rst.getString( " filename "); 18 if(fn== null){ 19 out.println( " </script>alert('无此文件');</script> "); 20 } else{ 21 String filename = URLEncoder.encode(fn, " UTF-8 "); 22 // response.addHeader("Content-Disposition", "attachment;filename=" + filename); 23 java.io.File temp = java.io.File.createTempFile( " temp ", " . "+rst.getString( " filetype ")); 24 InputStream infile = rst.getBinaryStream( " topic "); 25 FileOutputStream file = null; 26 file = new FileOutputStream (temp); 27 int chunk; 28 while ((chunk = infile.read()) != - 1) 29 file.write(chunk); 30 file.close(); 31 infile.close(); 32 33 SmartUpload su = new SmartUpload(); 34 // 初始化 35 su.initialize(pageContext); 36 // 设定contentDisposition为null以禁止浏览器自动打开文件， 37 // 保证点击链接后是下载文件。若不设定，则下载的文件扩展名为 38 // doc时，浏览器将自动用word打开它。扩展名为pdf时， 39 // 浏览器将用acrobat打开。 40 su.setContentDisposition( null); 41 // 下载文件 42 su.downloadFile(temp.getAbsolutePath()); 43 out.clear(); 44 out = pageContext.pushBody(); 45 // out.println(temp.getAbsolutePath()); 46 // out.println(fn); 47 temp.delete(); 48 } 49 } 50 } catch(Exception ex){ 51 ex.printStackTrace(); 52 } 53 }
六、热部署(与此jsp无关)：
Tomcat6的部署很简单，把war包复制到webapps下面，tomcat能自动部署（生成一个同名的目录），不过要记得删掉那个war包，否则可能会被下载。另外，如果直接修改目录下的jsp文件也能生效，class文件未测试。
此外，通过修改配置文件也能进行部署，有很多文章介绍，可参见，另外，有篇写得我看不懂的也附上，。
对于已经部署的应用，如需修改部署名，可以修改web.xml文件的<display-name>appname</display-name>
七、配置oracle的jndi数据源（与此jsp无关）：
主要是修改配置文件：server.xml
<GlobalNamingResources> <Resource name= " jdbc/test " type= " javax.sql.DataSource " maxActive= " 200 " maxIdle= " 10 " username= " username " maxWait= " 5000 " driverClassName= " oracle.jdbc.OracleDriver " password= " password " url= " jdbc:oracle:thin:@127.0.0.1:1521:test "/> </GlobalNamingResources>
另外还要配置content.xml：
<ResourceLink global= " jdbc/test " name= " jdbc/test " type= " javax.sql.DataSource "/>
在程序中的访问方法：
1 public static Connection getJNDIConnection(String jndiname) 2 { 3 if((jndiname== null)||(jndiname.equals( ""))) 4 jndiname= " java:comp/env/jdbc/test "; 5 Connection Conn= null; 6 if(Conn== null) 7 { 8 try{ 9 Context ctx = new InitialContext(); 10 if (ctx== null){ 11 return null; 12 } 13 DataSource ds = (DataSource) ctx.lookup(jndiname); 14 if (ds != null) { 15 Conn = ds.getConnection(); 16 } 17 } 18 catch(Exception ex) 19 { 20 Conn = null; 21 System. out.println( new java.util.Date().toLocaleString()+ " [错误] 无法新建数据库连接,jndi: "+jndiname+ " - "+ex.getMessage()); 22 return Conn; 23 } 24 } 25 return Conn; 26 }