在java中main函数如何调用外部非static方法

public class Test {
 
 public static void main(String[] args) {
  Employee employee = null;
  
  employee.setName("旺旺"); //有警告，况且这里也执行不下去
  employee.setEmail("ww@qq.com");
  employee.setPwd("123333");
  
  System.out.println(employee.getName()+" "+employee.getEmail()+" "+employee.getPwd());
 }
}

public class Test {
 
 public static void main(String[] args) {
  Employee employee = new Employee(); 
  
  employee.setName("旺旺"); 
  employee.setEmail("ww@qq.com");
  employee.setPwd("123333");
  
  System.out.println(employee.getName()+" "+employee.getEmail()+" "+employee.getPwd());
 }
}

public class Employee{
 private Integer id;
 private String name;
 private String pwd;
 private String email;
 
 public Employee() {
 
 }
 public Integer getId() {
  return id;
 }
 public void setId(Integer id) {
  this.id = id;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 
 public String getPwd() {
  return pwd;
 }
 public void setPwd(String pwd) {
  this.pwd = pwd;
 }
 public String getEmail() {
  return email;
 }
 public void setEmail(String email) {
  this.email = email;
 }
}

package com.chendi.objectNav;
public class MainClass {
  public static void main(String[] args){
    Circle circle = new Circle();
    Line line = new Line();
    //静态方法调用静态方法
    doSomeThing(circle);
    doSomeThing(line);
    //静态方法调用非静态方法
    MainClass mainClass = new MainClass();
    mainClass.noStatic();
  }
  public void noStatic(){
    //非静态方法调用非静态方法
    test1();
    //非静态方法调用静态方法
    test2();
  }
  public void test1(){
    System.out.print("1");
  }
  public static void test2(){
    System.out.print("2");
  }
  public static void doSomeThing(Shape shape){
    shape.erase();
  }
}