Compiling servlet version two code in HFSJ

[Nalla Balu]

Errors: i am getting while compiling, i have created the same directory structure given in HFSJ, can some one help me to proceed ?
C:\Servlets\Beer-v1\src\com\example\web>javac BeerSelect.java
BeerSelect.java:3: package src.com.example.model does not exist
import src.com.example.model.*;
^
BeerSelect.java:16: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
BeerSelect.java:16: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
3 errors

[khushhal yadav]

Hi Nalla

Do one thing
Go to this destination C:\Servlets\Beer-v1\src> in your command prompt.
Now execute the command
javac com/example/web/BeerSelect.java

Or the best way is to create a classes directory inside your src directory and then executing this command from the same destination.

javac -d classes com/example/web/BeerSelect.java

Now just copy the classes directory to your WEB-INF directory.

Regards,
Khushhal

[Nalla Balu]

package com.example.web;
 
 import com.example.model.*;
 import javax.servlet.*;
 import javax.servlet.http.*;
 import java.io.*;
 import java.util.*;
 
 public class BeerSelect extends HttpServlet {
 
 public void doPost(HttpServletRequest request,HttpServletResponse response)
    throws IOException,ServletException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
out.println("Beer Selection Advice <br>");
String c=request.getParameter("color");
BeerExpert be=new BeerExpert();
List result=be.getBrands(c);
Iterator it=result.iterator();
while(it.hasNext()){
out.println("<br> try:+it.next()");
}
}
}
 

Errors:C:\Servlets\Beer-v1\src>javac com/example/web/BeerSelect.java
com\example\web\BeerSelect.java:17: cannot access com.example.web.BeerExpert
bad class file: .\com\example\web\BeerExpert.java
file does not contain class com.example.web.BeerExpert
Please remove or make sure it appears in the correct subdirectory of the classpa
th.
BeerExpert be=new BeerExpert();
^
1 error

Thanks Kushal , help ?

[khushhal yadav]

Nalla, tell me
Where is your class BeerExpert located?
Exact path location..
If possible paste it's source code also.

Regards,
Khushhal

[Nalla Balu]

package com.example.model;
 
import java.util.*;
public class BeerExpert {
public List  getBrands(String color){
List brands =new ArrayList ();
if(color.equals("mild")){
brands.add("mild amber");
brands.add("mild moose");
}
else{
brands.add("else amber");
brands.add("else moose");
}
return(brands);
}
}
 

path:C:\Servlets\Beer-v1\src\com\example\model\BeerExpert.java

BeerSelect.java

 package com.example.web;
 
 import com.example.model.*;
 import javax.servlet.*;
 import javax.servlet.http.*;
 import java.io.*;
 import java.util.*;
 
 public class BeerSelect extends HttpServlet {
 
 public void doPost(HttpServletRequest request,HttpServletResponse response)
    throws IOException,ServletException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
out.println("Beer Selection Advice <br>");
String c=request.getParameter("color");
BeerExpert be=new BeerExpert();
List result=be.getBrands(c);
Iterator it=result.iterator();
while(it.hasNext()){
out.println("<br> try:+it.next()");
}
}
}
  

path:C:\Servlets\Beer-v1\src\com\example\web\BeerSelect.java

 <web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="httP://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">

 <servlet>
 <servlet-name>Ch3 Beer</servlet-name>
 <servlet-class>com.example.web.BeerSelect</servlet-class>
 </servlet>
  
  <servlet-mapping>
  <servlet-name>Ch3 Beer</servlet-name>
  <url-pattern>/SelectBeer.do</url-pattern>
  </servlet-mapping>
  
  </web-app> 

[khushhal yadav]

Nalla, see what's happening

Errors:C:\Servlets\Beer-v1\src>javac com/example/web/BeerSelect.java
com\example\web\BeerSelect.java:17: cannot access com.example.web.BeerExpert
bad class file: .\com\example\web\BeerExpert.java

It's looking for BeerExpert in web folder.
But your BeerExpert is in model folder.

So, in BeerSelect..
Instead of writing
import com.example.model.*;
Try with
import com.example.model.BeerExpert;

Otherwise, it should execute fine.

Regards,
Khushhal

[Nalla Balu]

Thanks kushal for supporting, i am trying to execute for 3 days could not do it. i am getting the same errors

C:\Servlets\Beer-v1\src\com\example\web>javac BeerSelect.java
BeerSelect.java:3: package com.example.model does not exist
import com.example.model.BeerExpert;
^
BeerSelect.java:17: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
BeerSelect.java:17: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
3 errors

[khushhal yadav]

Did you get it now???

Regards,
Khushhal

[khushhal yadav]

Nalla,

Try it in the way, I explained above.
You will get it.

Just now, I tried with your source code only without any modification and got compilation success.

C:\jakarta-tomcat-5.0.28\webapps\Testing\WEB-INF\src>javac com/example/web/BeerSelect.java
Note: .\com\example\model\BeerExpert.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

C:\jakarta-tomcat-5.0.28\webapps\Testing\WEB-INF\src>

See what was happening in your case, once you are in web, compiler has no way to look outside this.
So there is no way, compiler will be able to find model.
Hence you were getting those errors.

You can compile from any of the folder which is parent for both web and model.

Regards,
Khushhal
[ August 22, 2007: Message edited by: khushhal yadav ]

[Nalla Balu]

it is showing these errors while compiling ,can you tell me where to check for this errors

C:\Servlets\Beer-v1\src\com\example\web>javac BeerSelect.java
BeerSelect.java:3: package com.example.model does not exist
import com.example.model.BeerExpert;
^
BeerSelect.java:17: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
BeerSelect.java:17: cannot find symbol
symbol : class BeerExpert
location: class com.example.web.BeerSelect
BeerExpert be=new BeerExpert();
^
3 errors

thank you

[khushhal yadav]

Nalla

See what is happening in your case, once you are in web, compiler has no way to look outside it.
So there is no way, compiler will be able to find model.
Hence you are getting those errors.

You can compile it from any of the folder which is common parent for both web and model.

So compile it in the way, I explained above.

Go to this destination C:\Servlets\Beer-v1\src> in your command prompt.
Now execute the command
javac com/example/web/BeerSelect.java

Or the best way is to create a classes directory inside your src directory and then executing this command from the same destination.

javac -d classes com/example/web/BeerSelect.java

Your problem will be solved.
Still you face problem, let me know.

Regards,
Khushhal

[Nalla Balu]

it works


Thanks kushal for your continuing support

[khushhal yadav]

Nalla now Happy

Keep Smiling.. A Smile is something which never takes anything away from anyone. On the other hand helps to impart Smiles to others.

Regards,
Khushhal
[ August 22, 2007: Message edited by: khushhal yadav ]

[Christophe Verré]

That sounds very rude, but do you have SCJP ? You need it to pass SCWCD.

[khushhal yadav]

Hi Christophe

But none of us has been rude at any time.
And it's not only Nalla, I have seen many people who faced such kind of problem.
They find it difficult while dealing with packages.
There is nothing wrong in it. It's OK.
While preparing for SCJP, they might not have much exposure to such kind of thing.

Regards,
Khushhal

[Nalla Balu]

Thanks Kushal

got 75% scjp5 three months ago