如何在Java中的相同程序包和相同目录中调用类？

Question

Basically I have:

package duck.reg.pack;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet {
    private static final long serialVersionUID = 1L;
    public Test() {
        super();
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.getWriter().append("Served at: ").append(request.getContextPath());
        DBConnect DB = new DBConnect();
    }
}

Class to call At Test.java:

package duck.reg.pack;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DBConnect {
    private Connection con;
    private Statement st;

    public DBConnect(){
        System.out.println("Hi there!");
        return;
    }
}

Both File Directory Location:

C:\classes\duck\reg\pack\Test.java  +  DBConnect.java

The problem is that when I compile the program with command:

C:\classes\duck\reg\pack>javac -cp "C:\Users\Unknown\JavaEEWorkspace\lib\*" Test.java

This error is thrown:

Test.java:16: error: cannot find symbol DBConnect connect = new DBConnect();

I googled a little and I found I could remove the .java Extension from Test while compiling it and I did so But Then I got this error:

error: Class names, 'Test', are only accepted if annotation processing is explicitly requested 1 error

All replies are much appreciated :)

Answer 1

You need to run the compiler from the top package (which is at the root of the tree on the filesystem). So cd to

cd C:\classes

And run

javac -cp "C:\Users\Unknown\JavaEEWorkspace\lib\*" duck\reg\pack\*.java

Answer 2

为了找到DBConnect，我们需要使用-cp（或-classpath）选项来指定包com.yyy的基本目录。

javac -cp "d:\lib\*" d:\myJavaProject\pkg\*.java

Answer 3

write at the top

import duck.reg.pack.DBConnect;

in the class that you want to import it.

Why don't you use IntelliJ it will do it for you ?