编译时错误：package javax.servlet 不存在 import javax.servlet.*

Question

I have set class path as follow: CLASS_PATH: C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib;C:\Program Files (x86)\Java\mysql-connector.jar;C:\Program Files (x86)\Java\sqljdbc_8.2\enu\mssql-jdbc-8.2.0.jre8.jar;

and I also tried using jar file at compile time:- java -cp C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar Hello.java

java -cp "C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar" Hello.java

java -cp .;C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar Hello.java

java -cp ".;"C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar" Hello.java

java -cp C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar;. Hello.java

java -cp "C:\Program Files\Apache Software Foundation\Tomcat 10.0\lib\servlet-api.jar";. Hello.java

I also tried replacing -cp with classpath but still I get the following errors every single time:

C:\Program Files\Apache Software Foundation\Tomcat 10.0\webapps\16 servlet\WEB-INF\classes>javac -cp .;servlet-api.jar; Hello.java
Hello.java:2: error: package javax.servlet does not exist
import javax.servlet.*;
^

Hello.java:3: error: cannot find symbol
public class Hello implements Servlet
                              ^
  symbol: class Servlet

Hello.java:5: error: cannot find symbol
        public void init(ServletConfig sc)throws ServletException
                         ^
  symbol:   class ServletConfig
  location: class Hello

Hello.java:5: error: cannot find symbol
        public void init(ServletConfig sc)throws ServletException
                                                 ^
  symbol:   class ServletException
  location: class Hello

Hello.java:9: error: cannot find symbol
        public ServletConfig getServletConfig()
               ^
  symbol:   class ServletConfig
  location: class Hello

Hello.java:13: error: cannot find symbol
        public void service(ServletRequest req,ServletResponse res)throws ServletException
                            ^
  symbol:   class ServletRequest
  location: class Hello

Hello.java:13: error: cannot find symbol
        public void service(ServletRequest req,ServletResponse res)throws ServletException
                                               ^
  symbol:   class ServletResponse
  location: class Hello

Hello.java:13: error: cannot find symbol
        public void service(ServletRequest req,ServletResponse res)throws ServletException
                                                                          ^
  symbol:   class ServletException
  location: class Hello
8 errors

My Hello.java Servlet file:-

    import java.io.*;
    import javax.servlet.*;

public class Hello implements Servlet
{
    public void init(ServletConfig sc)throws ServletException
    {

    }
    public ServletConfig getServletConfig()
    {
        return null;
    }
    public void service(ServletRequest req,ServletResponse res)throws ServletException
    {
        String name=req.getParameter("name");
        PrintWriter out=res.getWriter();
        out.println("Hello "+name);
    }
    public String getServletInfo()
    {
        return null;
    }
    public void destroy()
    {

    }
}

tbh I tried other Servlet java program as well on netbeans IDE and it is running perfectly but I am not able to configure it explicitly myself even after searching and trying every possible solution out there, guys please help me resolve it.

Answer 1

Tomcat 10 is currently a milestone build, so not really good for first steps or meaningful development work, unless you specifically want to go after the root cause of your problem:

Tomcat 10 is not backwards compatible as the whole Java EE (or whatever label it flew under) is now replaced with the new Jakarta EE, thus your import javax.servlet.* now needs to be import jakarta.servlet.* .

Instead of adapting everything right now, you'll probably be happier by just utilizing Tomcat 9 and go with the old and (documented everywhere) javax.servlet.*