修改成这样 html> <head><title>usebean动作范例</title> </head> <body> <%@ page language="java" contentType="text/html;charset=gb2312"%> <jsp:useBean id="dat" scope="page" class="mybean"/> my name is: <% out.println(dat.getname());%> </body> </html>
修改后的程序如下:<html> <head><title>usebean动作范例</title> </head> <body> <%@ page language="java" contentType="text/html;charset=gb2312"%> <jsp:useBean id="dat" scope="page" class="mypkg.mybean"/> my name is: <%out.println(dat.getname());%> </body> </html> mybean.java: package mypkg; public class mybean{ String name; mybean(){ name="du"; }public String getname(){ return name;} } 将mybean.java进行编译后得到的类放入文件夹mypkg中,请问您所说的mypkg放在WEB-INF\classes下,WEB-INF\classes是examples文件夹下的,还是我自己建的myapp\WEB-INF\classes? 我都放了,但还是有如下错误?
org.apache.jasper.JasperException: Unable to compile class for JSP An error occurred at line: 6 in the jsp file: /usebean_action.jsp Generated servlet error: [javac] Compiling 1 source file D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:48: package mypkg does not exist mypkg.mybean dat = null; ^ An error occurred at line: 6 in the jsp file: /usebean_action.jsp Generated servlet error: D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:50: package mypkg does not exist dat = (mypkg.mybean) pageContext.getAttribute("dat", PageContext.PAGE_SCOPE); ^ An error occurred at line: 6 in the jsp file: /usebean_action.jsp Generated servlet error: D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:53: package mypkg does not exist dat = (mypkg.mybean) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "mypkg.mybean");
我这里试过了,没错啊,结果是:my name is: du 你的web应用设置好了吗?conf\server.XML设置好了吗?
<?xml version="1.0" encoding="ISO-8859-1"?>server.xml放在D:\Program Files\Tomcat 4.1\webapps\myapp\WEB-INF下,内容是:<!DOCTYPE web-app PUBLIC "-/ Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app> <display-name>My Web Application</display-name> <description> A application for test. </description> </web-app>
上个帖子贴错了。server.xml放在D:\Program Files\Tomcat 4.1\webapps\myapp\WEB-INF下,内容是: <?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app PUBLIC "-/ Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app> <display-name>My Web Application</display-name> <description> A application for test. </description> </web-app>
to linghan2008(): 重新启动了一下tomcat,这回行了,没有错误了,结果是my name is: du ,真的很感谢!谢谢你的耐心!
只有这样才行,这也是TOMCAT的一个小问题,呵呵
<jsp:useBean id="dat" scope="page" class="mypkg.mybean"/>
我的问题,谁来帮我,急急啊!
html>
<head><title>usebean动作范例</title>
</head>
<body>
<%@ page language="java"
contentType="text/html;charset=gb2312"%>
<jsp:useBean id="dat" scope="page" class="mybean"/>
my name is: <%
out.println(dat.getname());%>
</body>
</html>
<head><title>usebean动作范例</title>
</head>
<body>
<%@ page language="java"
contentType="text/html;charset=gb2312"%>
<jsp:useBean id="dat" scope="page" class="mypkg.mybean"/>
my name is:
<%out.println(dat.getname());%>
</body>
</html>
mybean.java:
package mypkg;
public class mybean{
String name;
mybean(){
name="du";
}public String getname(){
return name;}
}
将mybean.java进行编译后得到的类放入文件夹mypkg中,请问您所说的mypkg放在WEB-INF\classes下,WEB-INF\classes是examples文件夹下的,还是我自己建的myapp\WEB-INF\classes?
我都放了,但还是有如下错误?
An error occurred at line: 6 in the jsp file: /usebean_action.jsp
Generated servlet error:
[javac] Compiling 1 source file
D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:48: package mypkg does not exist
mypkg.mybean dat = null;
^
An error occurred at line: 6 in the jsp file: /usebean_action.jsp
Generated servlet error:
D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:50: package mypkg does not exist
dat = (mypkg.mybean) pageContext.getAttribute("dat", PageContext.PAGE_SCOPE);
^
An error occurred at line: 6 in the jsp file: /usebean_action.jsp
Generated servlet error:
D:\Program Files\Tomcat 4.1\work\Standalone\localhost\myapp\usebean_action_jsp.java:53: package mypkg does not exist
dat = (mypkg.mybean) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "mypkg.mybean");
name="du";
}构造函数改为public 默认在别的包访问不到
http://community.csdn.net/Expert/TopicView.asp?id=3688699
bean放到web-inf/classes里边就可以了,注意按包名目录结构存储.
-mypkg
mybean.class
你的mybean()构造最好加上public
-mypkg
mybean.class
是什么意思?
该如何设置阿?
-mypkg
mybean.class
就是这样的:\WEB-INF\classes\mypkg\mybean.class
classPath还需要设置吗?
---------------
不用设置
--------------------------具体做法是:在mybean.java文件开头加上package mypkg;这句一定要加!!编译后放到\WEB-INF\classes\mypkg下,目录结构是自己建的
1.mybean.java
package mypkg;
public class mybean{
String name;
public mybean(){
name="du";
}public String getname(){
return name;}
}
2.usebean.jsp
<html>
<head><title>usebean动作范例</title>
</head>
<body>
<%@ page language="java" import="mypkg.mybean"
contentType="text/html;charset=gb2312"%>
<jsp:useBean id="dat" class="mypkg.mybean"/>
my name is:
<%out.println(dat.getname());%>
</body>
</html>
D:\Program Files\Tomcat 4.1\webapps\myapp\WEB-INF\classes\mypkg下。
运行还是有错误
PUBLIC "-/ Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>
<display-name>My Web Application</display-name>
<description>
A application for test.
</description>
</web-app>
<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app
PUBLIC "-/ Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>
<display-name>My Web Application</display-name>
<description>
A application for test.
</description>
</web-app>
位置是:<host....> 加在这里 </host>Tomcat版本不同可能不一样,你可以查相关资料
其实,这个D:\Program Files\Tomcat 4.1\webapps\myapp\WEB-INF下的server.xml是我自己建的,内容我也不理解,按照他人的指点考到里面的。