Trouble compiling java files inside the packages.

Question

Hello I have a question in Java when compiling with packages. Can anyone Help??
My 2 java files BeerSelect2.java & BeerExpert.java are in packages com.example.web & com.example.model respectively.
C:\MyProjects\beerV1\src\com\example\web\BeerSelect2.java
and
C:\MyProjects\beerV1\src\com\example\model\BeerExpert.java
I have compiled the BeerExpert.java in the model package.(ie the class file for BeerExpert is in the com.example.model package.)
My BeerSelect2 file which is inside the web folder is like this
package com.example.web;
import com.example.model.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class BeerSelect2 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");
out.println("<br> Got Beer color "+c);
BeerExpert be=new BeerExpert();
List result=be.getBrands(c);
response.setContentType("text/html");
out.println("BEER SELECTION ADVICE <br>");
Iterator it=result.iterator();
while(it.hasNext())
out.print("<br> try: "+it.next());
This shows 3 comile errors.
& the BeerExpert.java file which is in the model folder is like this:
package com.example.model;
import java.util.*;
public class BeerExpert
public List getBrands(String color)
List brands=new ArrayList();
if(color.equals("amber"))
brands.add("Jack Amber");
brands.add("Red Moose");
else
brands.add("Jale pale Ale");
brands.add("Gout Stout");
return (brands);
This compiles fine in the model folder.
Now when I'm trying to compile my BeerSelect2.java in the 'web' folder in which I'm trying to import the com.example.model.* which is as follows
C:\MyProjects\beerV1\src\com\example\web>javac BeerSelect2.java
which gives 3 errors like this
BeerSelect2.java:3: package com.example.model does not exist
import com.example.model.*
^
BeerSelect2.java:22:cannot find symbol
symbol: class BeerExpert
location: class com.example.web.BeerSelect2.
BeerExpert be=new BeerExpert();
^
BeerSelect2.java:22:cannot find symbol
symbol: class BeerExpert
location: class com.example.web.BeerSelect2.
BeerExpert be=new BeerExpert();
^
Can anyone help???

Answer 1

Since the classes are part of the com.example.web and com.example.model packages the most straight forward way to compile is from the folder containing "com". Assuming you want the resulting .class files to be in the same folders are their associated .java source files:
C:\MyProjects\beerV1\src\> javac -cp . com\example\model\BeerExpert.java
C:\MyProjects\beerV1\src\> javac -cp . com\example\web\BeerSelect2.javaThe -cp . part is there to set the classpath (the location that the compiler will use to locate java classes) and thereby let the compiler make sense of the import statements.
The presence of "src" in the directory path strongly suggests, however, that the intention is not to have source and class files end up in the same directory. If this is the case read up on the syntax of the http://download.oracle.com/javase/6/docs/technotes/tools/windows/java.html (java.exe) and http://download.oracle.com/javase/6/docs/technotes/tools/windows/javac.html (javac.exe) commands. (paying attention to how searching for types is done). Also read up on any documentation you were given for building the application (if you are modifying something already given).
If you are using an IDE you should say.