javaBean本几部实现。
首先是编class
然后放到那里。
然后在程序中
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
不懂谁能举个例子
首先是编class
然后放到那里。
然后在程序中
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
不懂谁能举个例子
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
但是它的javabean是class是放在那里呢。
我的是win2000+j2sdk1.4+tomcat4.3+sqlserver2000
放在这个包里
这个包需方在设过classpath的目录里
这个目录下有好多目录和程序
都有什么用呀
当作
import com.database.ConnectDB;
ConnectDB connect = new ConnectDB();
来理解(这只是一种认识方式,不一定是jsp中usebean的机制--因为我也不明白)“但是它的javabean是class是放在那里呢”
web项目所在的目录\WEB-INF\classes\com\database\ConnectDB.class
不难服务器找不到
然后转到你的web文件夹中的web-inf下的classes文件夹里,在这里建立一个以你的javabean里打包的包名为名字的文件夹,然后把刚才编译好的class文件放在这下面。
剩下的我把我的代码给你吧。是一个检测用户登陆的bean:
package mypackage;import java.sql.*;public class CheckBean
{
private String Username = null;
private String Password = null; public String getUsername()
{
return Username;
} public void setUsername(String newUsername)
{
Username = toChinese(newUsername);
} public String getPassword()
{
return Password;
} public void setPassword(String newPassword)
{
Password = toChinese(newPassword);
}
public int IsSuccessed()
{
try
{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://127.0.0.1;databasename=LunTan;user=sa;pwd=");
String sql = "select password from userimf where username = ?";
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setString(1,Username);
ResultSet rs = stmt.executeQuery();
String passwordtemp;
if (rs.next())
{
passwordtemp = rs.getString("password");
rs.close();
}
else
{
return 0; //用户名不存在!!!
}
stmt.close();
conn.close();
if (Password.equals(passwordtemp))
{
return 2; //密码正确!!!!
}
else
{
return 1; //用户名和密码不符合!!!
}
}
catch (SQLException e)
{
System.out.println(e.getMessage());
return -1; //SQL语句有问题!!!
}
catch(Exception e)
{
return -2 ; //连接不成功!!!
}
}
private String toChinese(String strvalue)
{
try
{
if (strvalue == null)
{
return null;
}
else
{
strvalue = new String (strvalue.getBytes("ISO8859_1"),"GBK");
return strvalue;
}
}
catch (Exception e)
{
return null;
}
}
在就是jsp中调用的代码:
<jsp:useBean id="CheckBean" scope="page" class="mypackage.CheckBean">
<jsp:setProperty name="CheckBean" property="*"/>
</jsp:useBean>
<%
int i = CheckBean.IsSuccessed();
if (i < 0)
{
out.println("系统错误,请原谅!");
return;
}
else if(i == 0)
{
out.println("您的用户名并不存在,请重新登录!");
return;
}
else if(i == 1)
{
out.println("您的密码不正确,请重新登录!");
return;
}
else
{
out.println("恭喜您成功登录!");
return;
}
}
%>
package com.databasepublic void ConnectDB()
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
ID是你在你的SCRIPT中的用的标识,例如你的类中有如下方法。sql_query();
那么在
〈%
connect.sql_query();
%>
类,在这里呀?
\WEB-INF\classes\com\database\ConnectDB.class
还有个
ConnectDBConn.class
是做什么用的
而是本来就应该放在那里
呵呵“ConnectDBConn.class是做什么用的”
看名字,应该是封装了数据库连接
你不是有代码么?看看就明白了啊
谁有这个类的java源码我想改数据库名,ConnectDB.class
你可以把<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
当作
import com.database.ConnectDB;
ConnectDB connect = new ConnectDB();
来理解(这只是一种认识方式,不一定是jsp中usebean的机制--因为我也不明白)“但是它的javabean是class是放在那里呢”
web项目所在的目录\WEB-INF\classes\com\database\ConnectDB.class想请问zcjl(莫等闲,白了少年头) 为什么我的WEB-INF下没有你所写的后面的路径呢??
他的bean带有包结构com.database,所以他的WEB-INF\classes下面会有com\database\ConnectDB.class如果你的bean中定义的是package com.zcjl.example;
那么你的路径则应该是web项目所在的目录\WEB-INF\classes\com\zcjl\example\ConnectDB.class举一反三
小颖Java源代码反编译超级引挚V1.4版
所以我说明的时候都是这样的:
“web项目所在的目录”\WEB-INF\classes\com\zcjl\example\ConnectDB.class
我现在把.class文件放在自己建立的目录下,例如:webapps\myapp\web-inf\class\mypackage下,那我在地址栏里怎么输入呢???那放在默认的目录下又怎么输入呢??谢谢了!!
不懂,使用javabean不是在地址栏中输入,而是通过jsp来调用的,如:
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
<jsp:useBean id="TheBean" scope="page" class="mybean.FileUploadBean " />
<%
String TheBean=null;
TheBean.doUpload(request);
%>
FileUploadBean代码:
import java.io.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletInputStream;public class FileUploadBean {public void doUpload(HttpServletRequest request) throws
IOException {
PrintWriter pw = new PrintWriter(
new BufferedWriter(new FileWriter("d:\\upload")));
ServletInputStream in = request.getInputStream();int i = in.read();
while (i != -1) {
pw.print((char) i);
i = in.read();
}
pw.close();
}
}
编译错误:
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 0 in the jsp file: /jsp1.jspGenerated servlet error:
[javac] Compiling 1 source fileC:\tomcat\work\Standalone\localhost\test\jsp1_jsp.java:41: package mybean does not exist
mybean.FileUploadBean TheBean = null;
^An error occurred at line: 0 in the jsp file: /jsp1.jspGenerated servlet error:
C:\tomcat\work\Standalone\localhost\test\jsp1_jsp.java:43: package mybean does not exist
TheBean = (mybean.FileUploadBean ) pageContext.getAttribute("TheBean", PageContext.PAGE_SCOPE);
^An error occurred at line: 0 in the jsp file: /jsp1.jspGenerated servlet error:
C:\tomcat\work\Standalone\localhost\test\jsp1_jsp.java:46: package mybean does not exist
TheBean = (mybean.FileUploadBean ) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "mybean.FileUploadBean ");
^
3 errors
zcjl(莫等闲,白了少年头) ,你好!可以给我看看是什么原因吗??我的bean放在webapps\myapp\web-inf\class\mybean下的,谢谢先!!
package ejb.krsoft.ora;/**
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2002</p>
* <p>Company: kerun</p>
* @author unascribed
* @version 1.0
*/
import java.io.*;
import java.sql.*;
import java.util.*;
import oracle.jdbc.driver.OracleDriver;
public class DBConnection
{
private String dbdriver = "oracle.jdbc.driver.OracleDriver";
private String dburl="jdbc:oracle:thin:@172.16.0.4:1521:frerp";
private String sdbUsrname = "kr863";
private String sdbPasswd = "krsoft"; Connection con=null;
public ResultSet rst=null;
Statement smt=null; public void init(){
rst=null;
try
{
Class.forName(dbdriver);
System.out.print("\n\n 1.恭喜你,初始化数据库驱动程序成功!!!\n");
}
catch(java.lang.ClassNotFoundException e)
{
System.err.println("\n\n 1.初始化数据库驱动程序出错");
}
}
public ResultSet executequery(String sql){
try
{
con=DriverManager.getConnection(dburl,sdbUsrname,sdbPasswd);
Statement smt=con.createStatement();
rst=smt.executeQuery(sql);
System.out.print("\n\n 2.恭喜你,查询数据库成功!!!即:==>>executequery()操作成功。\n\n");
}
catch(SQLException ex)
{
System.err.println("\n\n 2.操作查询数据库失败,请检查数据库地址、用户名、密码以及你的SQL语句是否正确。即:==>>executeQuery()出错。\n\n"+ex.getMessage());
}
return rst ;
}}
我建立个虚拟目录 10
我的bean放在 10 虚拟目录下
\WEB-INF\classes\com\database\ConnectDB.class
我在jsp中怎么调用? ? ?
<jsp:useBean id="connect" scope="page" class="这里怎么写com.database.ConnectDB"/>
^_^
其次,在jsp中这样写
<jsp:useBean id="TheBean" scope="page" class="mybean.FileUploadBean " />
<%
String TheBean=null;
是很不正确的,TheBean既然是一个Bean的实例化对象,就不能再被声明为String对象了最后,你那个bean看得我实在是郁闷
等我下班了帮你修正一下
我的bean放在 10 虚拟目录下
\WEB-INF\classes\com\database\ConnectDB.class
我是这么调用的
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
提示错误!
是什么原因呀?
HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 13 in the jsp file: /zuzhijiagou/diqu/area.jspGenerated servlet error:
[javac] Compiling 1 source fileD:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\10\zuzhijiagou\diqu\area_jsp.java:7: package library.function does not exist
import library.function.*;
^
D:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\10\zuzhijiagou\diqu\area_jsp.java:329: package com.database does not exist
com.database.ConnectDB connect = null;
^An error occurred at line: 13 in the jsp file: /zuzhijiagou/diqu/area.jspGenerated servlet error:
D:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\10\zuzhijiagou\diqu\area_jsp.java:331: package com.database does not exist
connect = (com.database.ConnectDB) pageContext.getAttribute("connect", PageContext.PAGE_SCOPE);
^An error occurred at line: 13 in the jsp file: /zuzhijiagou/diqu/area.jspGenerated servlet error:
D:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\10\zuzhijiagou\diqu\area_jsp.java:334: package com.database does not exist
connect = (com.database.ConnectDB) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "com.database.ConnectDB");
^
4 errors
<%@ page language="java" contentType="text/html;charset=gb2312"%>
<%@ taglib uri="/WEB-INF/MyTaglib.tld" prefix="mytag" %>
<%@ page import="library.function.*"%>
<%@ page import="java.sql.*"%>
<%@ include file="/msg/init.inc"%>
<%@include file="/include/tools/Tools.jsp"%>
<jsp:useBean id="connect" scope="page" class="com.database.ConnectDB"/>
<%
int ipersonnelID = userid;
String sql_query = null;
ResultSet rs_query = null;
sql_query = "select diqu_ID,diqu_name,root_id from area where root_id='0' ";
// sql_query = "select NOTE_DETAIL.ID noteid,NAME,PHONE,MOBILEPHONE,EMAIL,GROUPID from NOTE_DETAIL,NOTE_GROUP where NOTE_GROUP.ID=NOTE_DETAIL.GROUPID and NOTE_DETAIL.PERSONNELID= "+ipersonnelID+" order by NAME ASC";
int intPageSize=0;
int intRowCount=0;
int intPageCount=0;
int intPage=0;
String strPage=""; intPageSize=1; //每页显示的总条数
strPage = request.getParameter("page");
if(strPage==null || strPage.equals(""))
{
intPage = 1;
}
else
{
intPage = Integer.parseInt(strPage);
if(intPage<1)
intPage = 1;
}
rs_query = connect.query(sql_query);
rs_query.last();
intRowCount = rs_query.getRow();
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>通讯录</title>
<link href="/include/css/web.css" rel="stylesheet" type="text/css">
</head>
<script>
<!--
function deleterecord(rsid,tablename,path)
{
if (confirm('你真的要取消该记录吗?'))
{
url="/include/jsp/DeleteTableByID.jsp?id="+rsid+"&tablename="+tablename+"&path="+path;
window.location.href=url;
}
}
-->
</script>
<body leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<div align="center">
<%
if(intRowCount==0)
{
%>
<table width="100%" border="0" align="center" cellpadding="0" cellspacing="0" bgcolor="#efefef">
<TBODY>
<tr>
<td align="center" valign="middle">
<br>
<br>
对不起!目前没有记录!
</td>
</tr>
</TBODY>
</table>
<%
}
else
{
intPageCount = (intRowCount+intPageSize-1) / intPageSize;
if(intPage>intPageCount)
{
intPage = intPageCount;
}
if(intPageCount>0)
{
rs_query.absolute((intPage-1) * intPageSize + 1);
}
%>
<table width="778" border="0" align="center" cellpadding="0" cellspacing="0" bgcolor="#efefef">
<tr>
<td align="left" valign="top"><p>
<strong>通讯录维护</strong></p>
<TABLE cellSpacing=0 cellPadding=0 width="80%" border=0 align="center">
<TBODY>
<TR>
<TD bgColor=#000000> <TABLE cellSpacing=1 cellPadding=4 width="100%" border=0>
<TBODY>
<TR align="center" bgColor=#006699 class="T14">
<TD width="20%" noWrap><strong><font color="#FFFFFF">ID</font></strong></TD>
<TD width="20%" noWrap><strong><font color="#FFFFFF">姓名</font></strong></TD>
<TD width="20%" noWrap><strong><font color="#FFFFFF">手机</font></strong></TD>
<TD width="20%" noWrap><strong><font color="#FFFFFF">Email</font></strong></TD>
<TD width="20%" noWrap><strong><font color="#FFFFFF">维护</font></strong></TD>
</TR>
<%
int diqu_ID = 0;
String diqu_name = "";
String root_id = "";
String strMobilePhone = null;
String strEmail = null;
int groupID = 0;
int i = 0;
while(i<intPageSize && !rs_query.isAfterLast())
{
diqu_ID= rs_query.getInt("diqu_ID");
diqu_name = rs_query.getString("diqu_name");
root_id = rs_query.getString("root_id");
// strMobilePhone=strMobilePhone==null?"无":strMobilePhone.trim();
//strEmail= rs_query.getString("EMAIL");
//strEmail=strEmail==null?"无":strEmail.trim();
// groupID = rs_query.getInt("GROUPID");
i++;
%>
<TR bgColor=#ffffff class="title12">
<TD width="20%" align=center noWrap><%=i%></TD>
<TD width="20%" align=center noWrap><a href="/addresslist/AddressInfoView.jsp?id=<%//=detailID%>" ><%=diqu_ID%></a></TD>
<TD width="20%" align=center noWrap><%=diqu_name%></TD>
<TD width="20%" align=center noWrap><%=root_id%></TD>
<TD width="20%" align=center noWrap><a href="/addresslist/AddressModify.jsp?id=<%//=detailID%>" >编辑</a>|<a href="javascript:deleterecord('<%//=detailID%>','NOTE_DETAIL','/addresslist/AddressIndex.jsp')" >删除</a></TD>
</TR>
<%
rs_query.next();
}
rs_query.close();
%>
</TBODY>
</TABLE></TD>
</TR>
</TBODY>
</TABLE>
<br>
<table width="80%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="35" colspan="2" align="right" bgcolor="#efefef">
共<%=intRowCount%>条 页:<%=intPage%>/<%=intPageCount%> <%if(intPage>1){%>
<a href="area.jsp?page=1">首页</a>
<a href="area.jsp?page=<%=intPage-1%>">上一页</a>
<%}
else
{
%>
首页
上一页
<%}%>
<%if(intPage<intPageCount){%>
<a href="area.jsp?page=<%=intPage+1%>">下一页</a>
<a href="area.jsp?page=<%=intPageCount%>">尾页</a>
<%}
else
{
%>
下一页
尾页
<%}
%>
</td>
</tr>
</table></td>
</tr>
</table>
<%
}
connect.closeConn();%>
<table width="778" border="0" align="center" cellpadding="0" cellspacing="0" bgcolor="#efefef">
<tr>
<td height="39" align="center" valign="top">
<TABLE cellSpacing=0 cellPadding=0 width="80%" border=0>
<tr align="center">
<td height="30" colspan="2" bgcolor="#efefef">
<input type="button" class="form" value="增加新用户" onclick="javascript:window.location.href='AddressAdd.jsp'">
</td>
</tr>
</table>
</td>
</tr>
</table>
</div>
</body>
</html>
我就没有这个目录