进来帮帮看看，为什么在类的本身创立自己对象不可以这样用的,该怎么处理_J2SE

进来帮帮看看，为什么在类的本身创立自己对象不可以这样用的
import java.util.*;
class ManOne{
Scanner scanner=new Scanner(System.in);
String name;
boolean sex;
long num;
ManOne ob[]=new ManOne[2];
String informationgroup[]=new String[2];
void getin(){
for(int i=0;i<ob.length;i++){
System.out.println("Input the man's name");
ob[i].name=scanner.nextLine();
System.out.println("Input the man's sex");
ob[i].sex=scanner.nextBoolean();
scanner.nextLine();
System.out.println("Input the man's num");
ob[i].num=scanner.nextLong();
scanner.nextLine();
}
}
public String toString(int i){
return "the name is"+ ob[i].name+"the sex is "+ob[i].sex+"the num is"+num;
}
void savetheinformation(){
for(int i=0;i<informationgroup.length;i++){
informationgroup[i]=ob[i].toString(i);
}
}
void shower(){
for(int i=0;i<informationgroup.length;i++){
System.out.println(informationgroup[i]);
}
}
void settheinformation(){
System.out.println("Input the man's name");
name=scanner.nextLine();
System.out.println("Input the man's sex");
sex=scanner.nextBoolean();
scanner.nextLine();
System.out.println("Input the man's num");
num=scanner.nextLong();
scanner.nextLine();
}
String getMenber(String name){
if(this.name.endsWith(name)){
return name;
}
else{
return null;
}
}

}
public class TestForManone {
public static void main(String args[]){
ManOne A=new ManOne();
A.getin();
A.savetheinformation();
A.shower();
}

}

------解决方案--------------------

Java code

ManOne ob[]=new ManOne[2];String informationgroup[]=new String[2];
------解决方案--------------------
ManOne ob[] = new ManOne[2];
这个需要初始化里面的对象啊兄弟，你只是创建了一个数组，但是数据里面没有初始化，所以[null,null]然后你用null来获取name属性，肯定就会空指针了。帮你改了一下
Java codeclass ManOne {    Scanner scanner = new Scanner(System.in);    String name;    boolean sex;    long num;    ManOne ob[] = new ManOne[2];    String informationgroup[] = new String[2];    void getin() {        for (int i = 0; i < ob.length; i++) {            System.out.println("Input the man's name");            ob[i].name = scanner.nextLine();            System.out.println("Input the man's sex");            ob[i].sex = scanner.nextBoolean();            scanner.nextLine();            System.out.println("Input the man's num");            ob[i].num = scanner.nextLong();            scanner.nextLine();        }    }    public String toString(ManOne[] ob,int i) {        return "the name is " + ob[i].name + " the sex is " + ob[i].sex                + " the num is" + num;    }    void savetheinformation(ManOne[] ob) {        for (int i = 0; i < informationgroup.length; i++) {            informationgroup[i] = ob[i].toString(ob,i);        }    }    void shower() {        for (int i = 0; i < informationgroup.length; i++) {            System.out.println(informationgroup[i]);        }    }    void settheinformation() {        System.out.println("Input the man's name");        name = scanner.nextLine();        System.out.println("Input the man's sex");        sex = scanner.nextBoolean();        scanner.nextLine();        System.out.println("Input the man's num");        num = scanner.nextLong();        scanner.nextLine();    }    String getMenber(String name) {        if (this.name.endsWith(name)) {            return name;        } else {            return null;        }    }}public class TestForManone {    public static void main(String args[]) {        ManOne A = new ManOne();        for(int i = 0; i < A.ob.length; i++){            A.ob[i] = new ManOne();        }        A.getin();        A.savetheinformation(A.ob);        A.shower();    }}