初级问题紧急求助：为什么我的javabean在jsp中调用时报告找不到方法？

编译了吗？
bean里为什么要加main()方法呀？

第一个文件：DOGException.javapackage p1.p1;public class DOGException extends Exception
{

public int Error; /**
* Constructs a DOG exception that contain
* an error number returned by DOG device driver
*
* @param ErrorNumber   Value returned by last call to DOG device driver.
*/

public DOGException( int ErrorNumber )
{
super( "Dog Operation Error " + ErrorNumber );
Error = ErrorNumber;
}
}第二个文件:GSDOG.java
package p1.p1;public class GSDOG
{

        //in most cases, this Global variable should be set zero.
        public  int DogCascade; //The globle variable DogAddr indicates the first memory
//address(range from 0 to 199) of user area in the MicroDog
//The sum of DogAddr and DogBytes should not exceed 200
public  int DogAddr;

//The globle variable DogBytes indicates the number of bytes
//in reading/writing operation or convertion
//The sum of DogAddr and DogBytes should not exceed 200
public  int DogBytes;

//The globle variable DogCode refers to the user code in
//the MicroDog and can be changed by DOGEDIT.exe
public  int DogPassword;

//The globle variable refers to the result of convererting operation
public  long DogResult;

//the globle variable DogData refers to the pointer variable
//which points to the data for writing/reading or converting

public byte[] DogData;

public GSDOG()
{
}

   /**
* Perform Dog Check Service
* @param none.
*/ public native int DogCheck();   /**
* Perform Dog Convert Service
* @param none.
*/ public native int DogConvert();   /**
        * Perform Dog Write Service
* @param none.
*/ public native int WriteDog();

/**
        * Perform Dog Read Service
* @param none.
*/ public native int ReadDog();

/**
        * Perform Dog DisableShare Service
* @param none.
*/ public native int  DisableShare(); /**
        * Perform Dog GetCurrentNo Service
* @param none.
*/ public native int  GetCurrentNo();

/**
* Static initializer
*/    static
    {
        try
        {
                System.loadLibrary("DOGJava");
        }
        catch( UnsatisfiedLinkError e )
        {
            System.err.println("Can't find library DOGJava.DLL");
            System.exit( -1 );
        }
     }
}      第三个文件：DOGGSMH.java
package p1.p1;public class DOGGSMH extends GSDOG
{ /**
*Checks whether a Dog is plugged in the parallel ports
*return 0 if success
*
*/
public boolean CallDogCheck()
throws DOGException
{
int retCode; if((retCode=DogCheck())!=0)
return false;
else
return true;
}
/**
*send a byte array to Dog and convert it to an int
*return 0 if success
*
*/ public void CallDogConvert()
throws DOGException
{
int retCode; if((retCode=DogConvert())!=0)
throw new DOGException(retCode);
else
{
System.out.println("Dog Convert is OK!" + "  Convert result is: "+ DogResult);
}
} /**
*write a byte array to Dog memory
*return 0 if success
*
*/ public void CallWriteDog()
throws DOGException
{
int retCode; if((retCode=WriteDog())!=0)
throw new DOGException(retCode);
else
{
System.out.println("WriteDog is OK!");
}
}
/**
*read Dog memory
*return 0 if success
*
*/ public void CallReadDog()
throws DOGException
{
int retCode;
char[] toPrint;
int i;
                int serialno=0;

toPrint=new char[DogBytes];

if((retCode=ReadDog())!=0)
throw new DOGException(retCode);
else
{
  System.out.println("Dog Read is OK!");
  System.out.print("Dog Read result ");
  for(i=0;i<DogBytes;i++)
  {
toPrint[i]=(char)DogData[i];

System.out.print(toPrint[i]);
  }
  System.out.println("");
} } /**
*get the current no
*return 0 if success
*
*/
public void CallGetCurrentNo()
throws DOGException
{
int retCode; if((retCode=GetCurrentNo())!=0)
throw new DOGException(retCode);
else
{
System.out.println("GetCurrentNo is OK!" + "  current no is: " + DogResult);
}
} /**
* disable share
*return 0 if success
*
*/
public void CallDisableShare()
throws DOGException
{
int retCode; if((retCode=DisableShare())!=0)
throw new DOGException(retCode);
else
System.out.println("DisableShare is OK!");
}}第四个文件：DogDemo.java（JSP调用这个)
package p1;import p1.p1.*;public class DogDemo
{
public boolean checkdog()
{
int retCode,i;

//System.out.println( "Microdog Sample Program for Java." );
//System.out.println( "Copyright (C) 2002 Rainbow China Co.,Ltd. All Rigths Reserved." );
       // System.out.println( "Implemented by JDK 1.2 release\n" );

DOGGSMH sample = new DOGGSMH();
sample.DogCascade = 0;
sample.DogPassword=0; sample.DogData = new byte[200];
for (i=0;i<200;i++)
sample.DogData[i]=(byte)(i+48);

try
{
sample.CallDisableShare();
}
catch(DOGException e)
{
//System.err.println( "  DisableShare Error: " + e.Error);
return false;
}

try
{
sample.CallDogCheck();
}
catch(DOGException e)
{
//System.err.println( "  Dog Check Error: " + e.Error);
return false;
} return true;
}

/* public static void main(String[] args) { DogDemo a = new DogDemo();
if(!a.checkdog())
{
System.out.println("The Call is fail!");
}
else
System.out.println("The Call is ok!");
} */} JSP:
<jsp:useBean id="dog" scope="page" class="p1.DogDemo" />
<%
out.println("The Counter is : " + "<BR>");
if(dog.checkdog()){
out.println("The Call is ok" + "<BR>");
}
else
{
out.println("The call is fail!");
}
%>然后就是上面的错！

多写了一个p1
java文件都在package p1中

bean 没有import 进来，在试一试

加了这个了<%@ page language="java" import="p1.DogDemo" %>在<jsp:useBean之前还不行。

static
    {
        try
        {
                System.loadLibrary("DOGJava");
        }
        catch( UnsatisfiedLinkError e )
        {
            System.err.println("Can't find library DOGJava.DLL");
            System.exit( -1 );
        }
     }
这段代码有问题，servlet中自己的代码不能退出System.exit( -1 );这样会造成web server退出。
你上面提的问题没有问题，不知道你那里怎么会错

我原来碰到过一次这样的问题，就是两个JSP页面都定义了一个名字为dog的javabean，实际上它们是不同的类，例如你在第一个页面定义：<jsp:useBean id="dog" scope="page" class="p1.DogDemo1" />另外一个页面定义：
<jsp:useBean id="dog" scope="page" class="p1.DogDemo" />
就会产生错误。

Bean里边可以加入main。
我建议你把jsp放到Jbuilder中检查一下，Jbuilder或许能帮你发现错误。

调试易

初级问题紧急求助：为什么我的javabean在jsp中调用时报告找不到方法？

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