程序运行错误是什么原因???

以下这段代码在运行时提示出错是什么原因？请高手指点.谢谢！
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JavaProcedure.java:3: 无法从静态上下文中引用非静态 变量 this
                Husband h=new Husband("11111","张三","1999-10-11",null);
                          ^
JavaProcedure.java:4: 无法从静态上下文中引用非静态 变量 this
                Wife w = new Wife("222222","李四","1998-11-12",null);
                         ^
JavaProcedure.java:25: 找不到符号
符号： 变量 Wife
位置： 类 JavaProcedure.Husband
                        Wife=w;
                        ^
3 错误


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public class JavaProcedure{
    public static void main(String[] args) {
        Husband h=new Husband("11111","张三","1999-10-11",null);
        Wife w = new Wife("222222","李四","1998-11-12",null);
        h.wife=w;
        w.husband=h;
        System.out.println(h.name+"的妻子的名字叫"+h.wife.name);
        System.out.println(w.name+"丈夫的名字叫"+w.husband.name);

        }
        
class Husband{
    String idcard;
    String name;
    String birth;
    Wife wife;
   
    public Husband(){

    }
    public Husband(String s1,String s2,String s3,Wife w){
            idcard = s1;
            name =s2;
            birth =s3;
 k

}
}
class Wife{
    String idcard;
    String name;
    String birth;
    Husband husband;

    public  Wife(){
    }
    public  Wife(String s1,String s2,String s3,Husband h){
            idcard = s1;
            name =s2;
            birth =s3;
            husband =h;
    }
}


}